# Diane Wahlstad and biofiltration making plants suffer and causing algae?



## Matti (1 Jan 2022)

What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.

But is this all wrong?

 I read Wahlstad's "The Ecology of the Planted Aquarium" and as every one who has read the book knows, one of the  confusing parts is chapter 7 "Plant nutrition and ecology":

-"Aquatic plants can use ammonium (NH4+), nitrite (NO2-) or nitrate (NO3-) as their nitrogen source. Many aquatic plants have been found to prefer ammonium over nitrates, and this preference is substantial."
-"My point is that plants readily take up ammonium from aquarium water and probably grow better using ammonium. This means that biological filtration (nitrification) can be de-emphasized in aquariums that contain healthy aquatic plants."
-"Plants use the N of ammonium (not nitrate) to synthesize their proteins.5 So if nitrifying bacteria convert all ammonium to nitrates, plants are forced– at a great energy cost– to convert nitrates back to ammonium.
The energy loss can be detrimental to sensitive plants."
-"In my planted tanks I have been surprised at how little biological filtration is actually required. When I decreased biological filtration (by removing the filter media in the canister filters), I had fewer problems with nitrate accumulation and water acidification."

So too strong bio-filtration makes the plants suffer and cause algae?
Did I do it wrong by installing an Oase Biomaster 250 to my 55l planted tank? Instead of keeping the HBO and just replacing the bio media with a course sponge?
What makes Wahlstad's book interesting that it is the only book about aquariums where the author has real data to back her claims. For e.g the number of scientifical papers of only chapter seven is 88.


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## erwin123 (1 Jan 2022)

Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.
> 
> But is this all wrong?
> 
> ...



In UKAPS the two things I learnt are "*Plants are the filter*" and "*Flow is king*"!

Before discovering UKAPS my canister filters were packed full of filter media. Now I have removed most of my matrix/ 3DM media.  However, I like crystal clear water so I have fine sponges and polishing pads. Since these reduce flow, I need to make sure I have 'extra' flow so I have 2 canister filters.

The part about Ammoniacal Nitrogen is why some of us live dangerously and insert Osmocote into the substrate, though there is certainly debate about whether it is beneficial to do so.


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## Nick potts (1 Jan 2022)

Matti said:


> Plants use the N of ammonium (not nitrate) to synthesize their proteins. So if nitrifying bacteria convert all ammonium to nitrates, plants are forced– at a great energy cost– to convert nitrates back to ammonium.


While this maybe true, it is clearly not the case that using KNO3 causes any issues with growing happy plants, as evidenced but the sheer number of people on here who dose EI levels and have great looking tanks with lush plant growth.



Matti said:


> Did I do it wrong by installing an Oase Biomaster 250 to my 55l planted tank? Instead of keeping the HBO



No, not IMO, while lots of bio media isn't needed, flow is very important in most tanks.


Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow



I find the opposite is true, at least on this forum anyway.

I run large canisiter filters in my tanks, i dont use any "bio media", just corse sponge. The advice you will often be given here is use minimal bio media as it really isn't needed, sponges work just fine.


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## dw1305 (1 Jan 2022)

Hi all, 


Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.


I don't see a filter that is a <"nitrate factory"> as a bad thing at all. 

The <"rapid removal"> of ammonia (NH3 /  NH4+) and nitrite (NO2-) is always a good thing for your livestock, even if plant growth may be slightly compromised. 

In terms of _how compromised?_ I think we are back in the <"all day buffet">, with the <"one-legged Irishman">.

cheers Darrel


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## Tim Harrison (1 Jan 2022)

Matti said:


> But is this all wrong?


No not at all. There is more than one route to success, and discussing those routes is something this forum does particularly well.
I think what is generally advocated though is a tried and tested method that will hopefully provide the greatest chance of success. This especially so when it comes to high-energy tanks.
But like any method it's not carved in stone and is open to interpretation and experimentation.

Personally I have had success growing aquatic plants using a variety of methods including the Walstad method and the polar opposite high-energy method.


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## Matti (2 Jan 2022)

I'm quite new in this hobby, my tank is just one year old (or the second one, i broke the first one). One thing I noticed right from the beginning is that the information you get is often confusing. Or that it's not explained in a convincing manner. Like "too low CO2 is the main cause of BBA", if that's the case why increasing CO2 to the optimal level has no effect on my BBA?
And when you start to learn a bit more, you notice that things are actually more complicated  compared how they are explained by the youtube experts. Like the in the case of ammonia and how to measure it, the difference between NH4+ and NH3, and how they are related to PH and temperature. And the notion that NH4+ is actually good for your plants and not so bad for your fish,  as long as NH3 stays low. The thing I'm trying to understand at the moment: 
But all these variables are actually what makes this hobby so interesting.
"Don't waste your time and money on test kits" is one of these confusing advice you sometimes get. "Just watch how your plants grow and you see the symptoms of fert deficiency". For a beginner it's not that easy. After a year I've learned to see K deficiency on Hygrophila, and fosphate deficiency on Cuba. Rest is just guessing.
And pardon me, but even George Farmer could have a use for test kits, if you think of his discus tank and how he took  of all plants, co2 and stopped fertilising. He was suspicious that the co2 caused distress to the discus. What I'm suspecting that the combination of hard water, high dosing of CO2 and Tropica, heavy fish food together with high temperatures, all the ingredients for the perfect storm, eg a NH4+/NH3 imbalance. But this too is again just guessing.


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## erwin123 (2 Jan 2022)

Matti said:


> I'm quite new in this hobby, my tank is just one year old (or the second one, i broke the first one). One thing I noticed right from the beginning is that the information you get is often confusing. Or that it's not explained in a convincing manner. Like "too low CO2 is the main cause of BBA", if that's the case why increasing CO2 to the optimal level has no effect on my BBA?


One of the causes of BBA seems to be CO2 instability (I got some BBA recently when tuning CO2 which result to CO2 levels being all over the place until I managed to get a stable setting).
After CO2 is stable, new BBA stops appearing, but the old BBA, you may need Excel/APT Fix/H2O2 to remove them.

You may also want to read through the 2hr Aquarist website - I find it useful as well.


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## dw1305 (2 Jan 2022)

Hi all,


Matti said:


> One thing I noticed right from the beginning is that the information you get is often confusing.


I have a bit of a jaundiced view of this, some companies are selling products that they know are useless (<"pH buffers etc">). I always tell people that this forum has *nothing to sell*, we just want people to have successful planted tanks.


Matti said:


> Like "too low CO2 is the main cause of BBA", if that's the case why increasing CO2 to the optimal level has no effect on my BBA?


We just don't know what causes, or sustains, outbreaks of BBA, we have some <"very detailed BBA threads">, but without any firm conclusions.


Matti said:


> ike the in the case of ammonia and how to measure it, the difference between NH4+ and NH3, and how they are related to PH and temperature. And the notion that NH4+ is actually good for your plants and not so bad for your fish, as long as NH3 stays low. The thing I'm trying to understand at the moment:


Scientists use TAN (Total Ammoniacal Nitrogen) as a measure to get around the pH / NH3 / NH4+ relationship. Personally I would always be very worried <"about NH4+ becoming NH3">.


Matti said:


> Don't waste your time and money on test kits" is one of these confusing advice you sometimes get.


You can get accurate values for nearly all the parameters that we are interested in, water companies do this all the time. The only provisos are time and money, and you need a lot of both.  How much? I'd guess even <"if you had the kit"> it would still be several thousand a year in running costs, that is without without costing the time of the operator.

If there was a dip meter you could pop in the tank, and it gave even ball-park figures for tank health, I would unequivocally recommend it.


Matti said:


> Just watch how your plants grow and you see the symptoms of fert deficiency". For a beginner it's not that easy. After a year I've learned to see K deficiency on Hygrophila, and fosphate deficiency on Cuba. Rest is just guessing.


I understand that, I'll be honest it is all guessing for me. I don't even try and <"work out which deficiency it is"> away from <"iron (Fe)">. I used a floating plant for the <"Duckweed Index"> to take CO2 out of the equation.

cheers Darrel


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## Matti (2 Jan 2022)

erwin123 said:


> One of the causes of BBA seems to be CO2 instability


If so , then why? It cannot be the CO2 itself, it must have something to do with the way plants use nutrients, as healthy, well growing plants don't get BBA.
Watching the video above, CO2 instability means fluctuating PH-levels, which in turn change the NH3 / NH4+ -levels. Which could have an effect on plants, but again, this is just guessing.


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## Tankless (2 Jan 2022)

Matti said:


> If so , then why? It cannot be the CO2 itself, it must have something to do with the way plants use nutrients, as healthy, well growing plants don't get BBA.
> Watching the video above, CO2 instability means fluctuating PH-levels, which in turn change the NH3 / NH4+ -levels. Which could have an effect on plants, but again, this is just guessing.



You should read the bba thread and post your theory's there.






						What exactly causes BBA? Part 2 - Bacterial imbalance
					

Following on from the What Exactly Causes BBA? thread, I've been reading some of the scientific literature around the subject and I'd like to make a radical proposal of an alternative cause of outbreaks of black beard algae (audouinella) in planted aquariums. I have listed some of the sources of...



					www.ukaps.org


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## erwin123 (2 Jan 2022)

Matti said:


> If so , then why? It cannot be the CO2 itself, it must have something to do with the way plants use nutrients, as healthy, well growing plants don't get BBA.
> Watching the video above, CO2 instability means fluctuating PH-levels, which in turn change the NH3 / NH4+ -levels. Which could have an effect on plants, but again, this is just guessing.


I am totally ok with not knowing the 'why'. Its sufficient for my purposes to understand what are the common practices widely adopted by aquascapers with "successful" tanks and to try them to see if it works for me.  For 'preventing' BBA, the 2 practices suggested are (i) keep CO2 stable, (ii) keep tank clean.

By the way, I never have BBA in my low tech tank. I have other types of algae, but I've not gotten BBA yet.  In contrast, BBA appears in my high tech tank when I mess around with the CO2. Maybe in my low tech tank, the amount of CO2 is 'stable' because I don't inject any, and I don't add liquid carbon?


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## dw1305 (2 Jan 2022)

Hi all,


erwin123 said:


> By the way, I never have BBA in my low tech tank. I have other types of algae, but I've not gotten BBA yet............. Maybe in my low tech tank, the amount of CO2 is 'stable' because I don't inject any, and I don't add liquid carbon?


I usually have a bit of BBA low tech in places where <"the snails can't graze">. 

cheers Darrel


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## Matti (2 Jan 2022)

erwin123 said:


> By the way, I never have BBA in my low tech tank. I have other types of algae, but I've not gotten BBA yet.  In contrast, BBA appears in my high tech tank when I mess around with the CO2. Maybe in my low tech tank, the amount of CO2 is 'stable' because I don't inject any, and I don't add liquid carbon?


I'm getting more convinced that you should keep the tank stable, CO2, PH, NH3 etc
Aquarium is a very complex system were all factors, like PH seem to have an influence on the others.
What I'm trying to do is the keep the values stable, that means  also not doing any more those massive, weekly water changes of 50-60%
Instead I change 25% weekly, it doesn't mess up the system so much.


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## jaypeecee (2 Jan 2022)

Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.
> 
> But is this all wrong?
> 
> I read Wahlstad's "The Ecology of the Planted Aquarium" and as every one who has read the book knows, one of the confusing parts is chapter 7 "Plant nutrition and ecology"


Hi @Matti 

For many years, I ran my tanks structured around filter-based biological filtration. Two or three years ago, I was told about Diana Walstad's _Ecology of the Planted Aquarium_. Being scientifically-minded, it just made an awful lot of sense to me. So I started to explore the scientific principles on which her methodology is based. For just over three months now, I have been running a 30 litre cube that incorporates some of Ms Walstad's ideas. It would be wrong to refer to it as a Walstad tank as it doesn't have an active substrate. It is proving to be successful at this early stage.

As far as I'm concerned, there is no right or wrong way to set up and run an aquarium. Do what works for you and your tank inhabitants.

JPC


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## jaypeecee (2 Jan 2022)

Matti said:


> If so , then why? It cannot be the CO2 itself, it must have something to do with the way plants use nutrients, as healthy, well growing plants don't get BBA.



Hi @Matti 

The following is an extract from that great resource, _The Krib*_:

"Another nutrient which may be related to the sustenance of red algae is inorganic carbon. This exists in the aquarium as dissolved CO2, bicarbonate or carbonates. The equilibrium of these carbon species depend on pH. Free CO2 becomes available at pH less than 8.0 and predominates when pH is less than 6.5. In my experience, I have only seen red algae in low alkalinity, low pH conditions. Tanks with calcareous substrates will push the carbonate equilibrium from CO2 to HCO3- and red algae seem to diminish. Accordingly, I used to see beard and brush algae in my South American cichlid tanks, but never in the Tanganyikan tanks with their crushed coral substrate. It seems that red algae may be among those algae and water plants that can only utilize free CO2".

So, what is your aquarium water alkalinity/KH and water pH?

BTW, BBA is a type of 'red algae'. For some bedtime reading (!), you may find this useful:









						Black beard algae (BBA) - Aquascaping Wiki
					

Red algae in the aquarium




					www.aquasabi.com
				




* The Krib (Aquaria and Tropical Fish)

JPC


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## Matti (3 Jan 2022)

My PH is between 6,6-7,0, depending at what time of the day I measure it, for how long CO2 has been on. KH6, GH10.
The CO2/PH -theory is interesting, I once had a hard water Tanganyika tank with no CO2 and no BBA, but it had no plants either. 
So CO2 it seems to be the key factor, as it is itself a nutrient for the plants. And when there is a CO2/PH problem, the slow growing plants will first show signs of distress and cannot protect agains BBA.


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## jaypeecee (3 Jan 2022)

Matti said:


> The CO2/PH -theory is interesting...


Hi @Matti & Everyone,

Yes, it's certainly something to keep very much in mind. For anyone reading this, perhaps you could indicate the presence (or not) of BBA in your tank(s) and report the tank water KH, pH and if CO2 injection is used. That may prove to be interesting. We'd only need a few measurements to get an idea. I guess it would be possible to set up a poll for this purpose? That may be better as it's a bit of a deviation from this thread's title!

JPC


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## erwin123 (4 Jan 2022)

one way of doing data analysis would have been to 
(i) go to the Journals subforum 
(ii) perform a search "BBA"
(iii) see the threads/journals that appear
(iv) analyse each journal - injected CO2 or no-injected CO2, other parameters, etc
See if any correlation.
Except that "BBA" was too short a search term  for the forum.... maybe I will do a gradually do a manual search of low tech tank journals for "BBA" 😅


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## erwin123 (4 Jan 2022)

The data extraction would look something like this - just picked out some journals for now - i could progressively add to it since I like browsing journals and viewing tank photos. Of course, accuracy could be increased if we sent the journal owners a survey for example, in case they had BBA but didn't mention it in their journal. (but since they mentioned other algae, no reason why they wouldn't mention BBA?)

I'm not out to prove or disprove any hypothesis, just collecting the data. Darrell has already mentioned that his low tech had BBA, so its not that BBA cannot exist in low tech. Maybe its not the fact that these tanks have no CO2 injection... but that they are small, for example... anyway, this is a long away from a statistically meaningful sample size...

There are some journals that I've not included because of a lack of information  - i..e. not really a journal, just a photo gallery.


Journal LinkDescriptionAny CO2?Any mention of BBA?Algae types mentioned








						My low tech shrimp nano cube (20 litres)
					

My first proper planted tank after experimenting with a biorb.  20l Dennerle cube kit, inc. their deponit mix substrate, led light and corner filter. Interpet nano heater (mostly to keep the shrimp warm - house gets pretty cold). Two bits of bogwood leaning against each other (pretty stable)...




					www.ukaps.org
				



My low tech shrimp nano cube (20 litres)​NoNoType not specified
Photo shows green algae on moss








						35L jungle
					

Tank - 35l dennerle scaper's tank  Light - dennerle 5w Heater - nano 50w Filter - Eheim biopower 160 with sponge and seachem matrix  Using seachem stability, tnc carbon and dennerle daily fertiliser  50% daily water changes to start Substrate - dennerle scaper's soil and ada la plata and root...




					www.ukaps.org
				



35L jungle​NoNo"slimy brown algae" on moss








						Referb and restart after 30 years. Low tech.
					

I have been meaning to start a journal for this little project for ages. I have all the pics, just have not found the inclination. So here goes: The tank has not had water in it for about 30 years. It is only a Small Tank 30.588L, size cm 49.4w x 25.8d x 26.5h It used to be my breeding tank. Had...




					www.ukaps.org
				



Referb and restart after 30 years. Low tech.​NoNo"brown algae"
"stringy algae"
"bluegreen algae"








						Marshlands
					

This is my first journal, but I want to learn so don't go easy on me. My main interest is in life right along the water’s edge with a side dish of epiphytes, so my tanks tend to have vegetation either spilling out of them or with a focus on more terrestrial species entirely. Most of the setups...




					www.ukaps.org
				



Marshlands​NoNo"Cyano"








						Naufragium / Shipwreck (Dennerle scaper 35)
					

The ‘big tank’ (well, 60p) set up is on hold for the foreseeable while we wait for building work, so I’ve treated myself to a Dennerle scaper’s tank 35 as a caridina shrimp tank. I’ve fancied having a go at some caridina for a while and the excuse is that this tank is small enough to move round...




					www.ukaps.org
				



Naufragium / Shipwreck (Dennerle scaper 35)​NoNo"algae on Anubias"
Type not mentioned, but plenty of photos, no BBA seen?








						The Mossy Spider (Nano Lowtech)
					

This journal is for my new tank, a 30cm-cube which sits on my desk. I got it to keep shrimp, as they don't like my main tank's rainwater, so I'm giving them some good, old-fashioned London tap.  I started my first tank in June, and have been completely taken over by it, MTS was inevitable! Along...




					www.ukaps.org
				



The Mossy Spider (Nano Lowtech)​NoNo"filamentous thread algae"


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## Matti (4 Jan 2022)

At the moment no BBA! I had a BBA problem for months and in the end I soaked all buces and Anubis in bleach. Now I'm trying to keep it coming back: no extra fish food, less lights and a new more powerful filter. The filter was changed before I read the Wahlstad article,  a bit confusing it that sense, but it's a good filter and at least I have now better water circulation. I also took changed rotalas to hydrophila 53B, again for better water circulation, added some floaters. Now I'm trying to keep the tank stable, less water changes and not too much fertilisers, yes I know "fertilisers don't cause algae" but I am not that convinced. Especially with too much iron.
PH is between 6,6-7,0; KH6, GH10. CO2 according to those values between 18-30. It's not stable but there is not much I can do about it as injection is controlled but timer, not by PH.
I dose Tropica Specialised 4ml weekly and keep NH3 between 10-20. Tropica is low in phosphates so I add 2ml phosphates weekly. And some iron and potassium every two weeks. It's a 55l tank.


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## Zeus. (4 Jan 2022)

Matti said:


> "Plants use the N of ammonium (not nitrate) to synthesize their proteins.



Well they have Oxygen in abundance during the day. Plants may only use the N, but when we eat Carbs ( and protein when diet is low in carbs) for energy all we are after is the release of energy from the electron change in orbit in the mitochondria within cells, there is normally a convoluted chemical pathway in most living things to get what they need.

Then sometimes what seems the preferred choice of an organism of a compound for its source of its needs its the organisms preferred pathway,  eg sugar in our diet is the body's first choice to use for energy for one simple reason, sugar is toxic to body if levels get too high ( and the level isn't that high either).

I have dosed my tank only urea as its source of N for quite some time and had no problems, I did do it drip feed in tank nearly 100 small doses weekly


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## robinj (6 Jan 2022)

Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.


This was valid in the beginning. She "recommends" HOB filters now (Filter Options These Days?). 

Everyone recommending Matrix was marketing hype. I came over this article - Aquarium , which is a comprehension of a forum thread HERE. I can really recommend it to read.  The conclusion is simple: nitrification is happening even in empty tank with no filtration at all.


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## dw1305 (6 Jan 2022)

Hi all,
@robinj thank you for posting this. 


robinj said:


> She "recommends" HOB filters now (Filter Options These Days?).


This is what the lady herself says in <"APC thread">


> _......... I don't trust canister filters. The canisters, because they are relatively sealed, can go severely anaerobic. If they clog up with debris, stop flowing, or the power goes off, the outflow of dead bacteria and toxins--once the filter starts back up again-- can kill the fish. It has happened a couple of times to me. Since the AquaClear is not sealed, there's no chance of it becoming anaerobic............Yes, regular cleaning is the key to keeping canister filters safe._


<"Which is definitely"> where I'm <"coming from"> as well.


robinj said:


> I came over this article - Aquarium , which is a comprehension of a forum thread HERE. I can really recommend it to read. The conclusion is simple: nitrification is happening even in empty tank with no filtration at all.


Another interesting one.  It just reinforces what we've said in various <"pumice">, <"biofilm">, <"oxygen"> and the small <"volume of media actually required"> threads.

I should have also said that <"Marcel"> is a former member of this forum and while we eventually had a bit of a falling out (and he left) I always found his postings really interesting. 

cheers Darrel


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## Matti (6 Jan 2022)

I changed my Dennerle HBO to a Biomaster 250, as I thought it would be a good thing to do, even in a 55l tank.
I have the old media in one basket, the others are as they came in the box.
I would have expected to see some difference in performance, as the Biomaster has 4xtimes the volume and media and double the flow. But non what so ever.
After inserting Tropica the nitrites rise, and it takes the same time to get them back to 0,05.
But the BioMaster is otherwise a great filter (as is the Dennerle).

Luckily I didn't follow the youtube "experts" and throw away the sponges and replace them with something  more "pro", would feel now like a total idiot.


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## robinj (6 Jan 2022)

dw1305 said:


> I should have also said that <"Marcel"> is a former member of this forum and while we eventually had a bit of a falling out (and he left) I always found his postings really interesting.


I discovered his blog randomly and I like that rarely seen scientific-based approach. What to say, people with strong views don't get along well.


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## dw1305 (6 Jan 2022)

Hi all, 


robinj said:


> What to say, people with strong views don't get along well


I think that was the issue, some disagreements and a fairly confrontational approach. 

Personally, I never had any problem with him at all and I wish he had stayed, because I thought / think he had / has a lot to offer. 

cheers Darrel


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## arcturus (6 Jan 2022)

robinj said:


> Everyone recommending Matrix was marketing hype. I came over this article - Aquarium , which is a comprehension of a forum thread HERE. I can really recommend it to read.  The conclusion is simple: nitrification is happening even in empty tank with no filtration at all.


In  my view, a filter is nothing more than an extension to the aquarium that acts as a refuge for bacteria to colonize. A tank without a filter can have more than enough surfaces to harbour nitrifying bacteria. If that amount of nitrification is sufficient or not mostly depends on bio load and plant mass of the tank. Filters are important not because of nitrification per se but because they promote water circulation and surface agitation (and therefore oxygenation), which are required for nitrification - but one can achieve the same effect with pumps/propellers instead of filters. Filters are mostly relevant for mechanical and chemical filtration and there might be other biological processes that are taking place inside a filter (e.g. decomposition of detritus).


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## dw1305 (6 Jan 2022)

Hi all,


arcturus said:


> ...... a filter is nothing more than an extension to the aquarium that acts as a refuge for bacteria to colonize. A tank without a filter can have more than enough surfaces to harbour nitrifying bacteria. If that amount of nitrification is sufficient or not mostly depends on bio load and plant mass of the tank. Filters are important not because of nitrification per se but because they promote water circulation and surface agitation (and therefore oxygenation), which are required for nitrification ......


Exactly that.


arcturus said:


> ..... Filters are mostly relevant for mechanical and chemical filtration and there might be other biological processes that are taking place inside a filter (e.g. decomposition of detritus).


That is the issue right there, I just wish they weren't called <"filters">.

Personally I don't want my <"filter to act as a syphon">, I actively want to keep all the <"organic debris and detritus"> out of the filter.

I want all of the <"mechanical filtration"> to have occurred before the water enters the filter. All I want in the filter are <"dissolved gases">, oxygen, CO2 and ammonia.

After that the only criterion that matters is that oxygen supply <"always exceeds the oxygen demand">.

cheers Darrel


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## jaypeecee (6 Jan 2022)

dw1305 said:


> Personally, I never had any problem with him at all and I wish he had stayed, because I thought / think he had / has a lot to offer.


Hi Everyone,

I contacted him about a year ago and he _seems_ to have turned his back on the aquatics hobby. I didn't pursue it any further as I thought it right to respect his decision. Still, he has done some great work and made valuable contributions to our hobby.

JPC


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## jaypeecee (6 Jan 2022)

arcturus said:


> In my view, a filter is nothing more than an extension to the aquarium that acts as a refuge for bacteria to colonize. A tank without a filter can have more than enough surfaces to harbour nitrifying bacteria.


Hi @arcturus & Everyone,

A few years ago, I had read that light could suppress nitrification. But, at the time, I was unable to obtain any figures to quantify the intensity/spectrum of light that was relevant. So, I just did a quick search and found the following:

"Culture irradiance below 250 μmol m−2 s−1 did not show a significant effect on nitrification activity...".* This is taken from wastewater treatment so, to what extent it is relevant in home aquaria, I do not know. The above irradiance figure is in excess of most/all aquarium lighting - to the best of my knowledge.

I also stumbled across this:

"Nitrifiers are light sensitive, especially toward ultraviolet (UV/ sunlight). Room light has a negative impact on bacterial activity as well. Colonizing the filter is therefore the preferred settlement of the bacteria, as it provides a dark environment. Light exposure (i.e. cleaning the filter) will not cause stress, as the time frame is too short allowing the colony to recuperate within hours"**.

* Influence of light intensity on bacterial nitrifying activity in algal-bacterial photobioreactors and its implications for microalgae-based wastewater treatment

** Nitrifying bacteria - Breaking down aquarium waste

I am very much aware that some aquarists successfully establish a nitrifying bacteria culture by taking a sample of substrate from another tank.

If light does indeed suppress nitrification, then a filter unit - canister or sponge - provides the right environment.

JPC


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## arcturus (6 Jan 2022)

Interesting articles! At the microscopic scale of bacteria, I believe bacteria would find plenty of shaded areas in most elements of hardscape and substrate, even if those are directly exposed to light.  If light is indeed a problem, then it would mainly affect the biofilm colonization on the glass surfaces. A major advantage of the external filter is that the nitrifying bacteria colonies are mostly left undisturbed, contrary to what happens inside the tank due to maintenance and other environmental factors.  But then the filter must have suitable conditions for nitrification, which might not be the case when it is packed full of fancy media...


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## heliophyte (6 Jan 2022)

arcturus said:


> A major advantage of the external filter is that the nitrifying bacteria colonies are mostly left undisturbed, contrary to what happens inside the tank due to maintenance and other environmental factors.


Which is one of the reasons why some people say you shouldn't clean your substrate too much I suppose.


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## aec34 (6 Jan 2022)

erwin123 said:


> erwin123 said:
> 
> 
> > The data extraction would look something like this - just picked out some journals for now..


Hi @erwin123 just chipping in since two of these journals are mine. I did have a little BBA in one of these tanks - but it only appeared on a plant which I bought which came from a CO2 injected tank. I trimmed the affected leaves, and it hasn’t come back so far. 🤔


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## arcturus (6 Jan 2022)

heliophyte said:


> Which is one of the reasons why some people say you shouldn't clean your substrate too much I suppose.


Not sure if it is because of the bacteria…Disturbing the substrate can release accumulated and unwanted substances into the water column.


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## dw1305 (6 Jan 2022)

Hi all,


heliophyte said:


> Which is one of the reasons why some people say you shouldn't clean your substrate too much I suppose.


I'm not keen on disturbing the substrate, mainly because of the reasons given by Stephan Tanner in <"Aquarium biofiltration">.


arcturus said:


> At the microscopic scale of bacteria, I believe bacteria would find plenty of shaded areas in most elements of hardscape and substrate, even if those are directly exposed to light.


I'm pretty sure that is right.


jaypeecee said:


> Culture irradiance below 250 μmol m−2 s−1 did not show a significant effect on nitrification activity...".* This is taken from wastewater treatment so, to what extent it is relevant in home aquaria, I do not know.


It would be interesting so see if anyone has published on the light sensitivity of <"Ammonia Oxidising Archaea (AOA) and COMAMMOX _Nitrospira_">_. _I'll see what I can find. I'd imagine there will be some research, purely because <"photobioreactors">* have been a recent research strand, including in the treatment of (ammonia containing) wastewater and they would need light for the algae.

*S. Akizuki, _et al._ (2020) "Application of nitrifying granular sludge for stable ammonium oxidation under intensive light," _Biochemical Engineering Journal,_


> *160. *says
> _".... This study compared the nitrification activity of dispersed and granular nitrifying sludges in batch assays under a wide range of light intensities. In a dispersed sludge reactor, the original nitrification activity in dark conditions (0 μmol photons m−2 s-1) was 0.85 mg-N g-SS–1 h–1. The activity significantly decreased to 0.43 and 0.25 mg-N g-SS–1 h–1, which correspond to 50 % and 70 % less than in dark condition, with light intensities of 450 and 1600 μmol photons m−2 s-1, respectively. In contrast, the activity in the granular sludge was not significantly inhibited by light exposure..._."



cheers Darrel


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## dw1305 (6 Jan 2022)

Hi all, 


dw1305 said:


> I'll see what I can find.


I'll need time to go through all the papers, but it looks like there should be plenty of them.  Hopefully a they will provide a definitive view of just how light sensitive AOB, AOA and _Nitrospira spp. _are, or possibly just lots of conflicting evidence. 

cheers Darrel


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## jaypeecee (6 Jan 2022)

dw1305 said:


> It would be interesting so see if anyone has published on the light sensitivity of <"Ammonia Oxidising Archaea (AOA) and COMAMMOX _Nitrospira_">_. _I'll see what I can find.


Hi @dw1305 

Yes, I agree entirely. I'll also have a look. I'm limited to what can be obtained for free. But, if I find something that is available to academia, I'll let you know.

JPC


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## jaypeecee (6 Jan 2022)

Hi @dw1305

Here's a candidate:









						Development of light-shielding hydrogel for nitrifying bacteria to prevent photoinhibition under strong light irradiation
					

Microalgae-nitrifying bacteria consortia have gained attention because photooxygenation of algae can supply oxygen to bacteria which eliminates the ne…




					www.sciencedirect.com
				




Obviously, the product being described is of minimal interest. And it may not address Nitrospira. But it may contain other useful, relevant information.

JPC


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## jaypeecee (6 Jan 2022)

Hi again, @dw1305 

This _may_ be of more interest:









						Effects of light and mass ratio of microalgae and nitrifiers on the rates of ammonia oxidation and nitrate production
					

This study investigated the effects of microalgae and light on nitrifying bacteria. The oxygen production rates of microalgae were measured at various…




					www.sciencedirect.com
				




I didn't expect to find much. So, rather than drip-feeding them to you, if I find more, I'll make a list.

JPC


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## tiger15 (7 Jan 2022)

Matti said:


> What you have been told is to get an expensive oversized filter, throw away the filter sponges and use Matrix with strong a flow. The filter is super effective in converting ammonium to nitrates which the plants will use. And this is good and the only right way to go.
> 
> -"In my planted tanks I have been surprised at how little biological filtration is actually required. When I decreased biological filtration (by removing the filter media in the canister filters), I had fewer problems with nitrate accumulation and water acidification."
> 
> ...


I don’t believe that removing bio media in the filter will reduce bio filtration, as there is plenty of beneficial bacteria in the substrate, plant and other surfaces as long as oxygenated water supply is unlimited.  I agree that having no or very coarse matrix in a canister filter to promote strong oxygenated flow is better off than having tight media that get clogged up  easily. I personally don’t use any canister filter but only HOBs for mechanical and wave maker to promote strong flow.






						Is expensive bio media worth it?
					

Could a heavily planted tank take the main role of biological filtration to the point any other filtration you have would end up becoming mechanical?  Yes, I think so. Plants and the substrate. I can see that happen if you have lots of plants relative to livestock and excellent flow throughout...



					www.ukaps.org
				




It’s true that plants can uptake ammonia more efficiently than nitrate, and so do algae.  If the soil is too hot in a Walstad setup, it can trigger algae until ammonia generation is subsided.  During photo period, plants will gobble up ammonia in completion with bb, but off photo period, bb is the only game in town to detoxify ammonia.  

Walstad book cited many references from outdoor ecological studies, but glass box environment is very different from outdoor environment, and direct extrapolation of the results is not always relevant and may lead to wrong conclusion.  For example, high nitrate and phosphate  is often associated with algal boom in natural water bodies, but not so in planted aquariums.


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## dw1305 (7 Jan 2022)

Hi all,


tiger15 said:


> I don’t believe that removing bio media in the filter will reduce bio filtration, as there is plenty of beneficial bacteria in the substrate, plant and other surfaces as long as oxygenated water supply is unlimited.


I would tend to agree, my guess is that the microbial assemblage will be fairly closely matched to the amount of nutrients (carbon, nitrogen, oxygen etc ) in the system, it is back to Liebig's limiting nutrients, but this time for microbes. If we ensure that <"oxygen isn't the limiting nutrient"> then things aren't likely to <"spiral out of control">.

The advantage would be that a planted system you would have some spare nitrification capacity if the nitrogen or carbon input suddenly rose


tiger15 said:


> but off photo period, bb is the only game in town to detoxify ammonia.


Plants will still take up some ions in the dark, we talked about the differences in <"active and passive uptake"> in <"iron deficiency">.

cheers Darrel


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## dw1305 (7 Jan 2022)

Hi all, 


jaypeecee said:


> This _may_ be of more interest:


That is probably about as good as we are going to get. 

I've found a review article  Liu, J. _et al_. (2017 )<"Advanced nutrient removal from surface water by a consortium of attached microalgae and bacteria: A review"> _Bioresource Technology _*241*, pp. 1127-1137 has a schematic figure of the composition of attached biofilms.  




 
I'd guess in most cases that dark areas aren't an issue due to the biofloc effect and the turbidity of the waste water. 

cheers Darrel


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## Matti (7 Jan 2022)

tiger15 said:


> Walstad book cited many references from outdoor ecological studies, but glass box environment is very different from outdoor environment, and direct extrapolation of the results is not always relevant and may lead to wrong conclusion.  For example, high nitrate and phosphate  is often associated with algal boom in natural water bodies, but not so in planted aquariums.


The problem with aquariums is the lack of real data. There are a lot of opinions and believes , but few real theories or models that would have been tested, measured and published.
The great thing in Walstads book is that she has a tried to understand what happens in a planted tank by using real data and studies, albeit from outdoor ecosystems.
And her opinion that too strong filtration is not beneficial for plants makes sense, supported by her own experiments.
And she was right when se recommended using floaters to control nitrates. I added some Frogbits to my 55l and it's just insane how they take up nutrients! I used to dose Tropica Premium 3ml weekly, now I'm dosing 8ml the have the same nitrates levels around 10ppm.
​


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## dw1305 (7 Jan 2022)

Hi all,


Matti said:


> And she was right when se recommended using floaters to control nitrates. I added some Frogbits to my 55l and it's just insane how they take up nutrients!


You are talking <"to the converted">, I'm a <"Frogbit obsessive">, but it was Diana Walstad's <"aerial advantage"> that led to the <"Duckweed Index"> and eventually _Limnobium laevigatum_ as my <"preferred "Duckweed">.

cheers Darrel


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## jaypeecee (7 Jan 2022)

Hi @dw1305 & Everyone,

We appear to have dismissed lighting as a potential inhibitor of nitrification in aquaria. Have I missed something? That's entirely possible as this is the first time I've been on UKAPS today.

JPC


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## MichaelJ (8 Jan 2022)

dw1305 said:


> Hi all,
> that led to the <"Duckweed Index"> and eventually _Limnobium laevigatum_ as my <"preferred "Duckweed">.



Hi Darrel, Perhaps you should rename it the Frogbit index.  I wish your advice on the "preferred duckweed" would have been more obvious to me before this happened 





When the duckweed really gets going its really hard to get rid of... its almost out competing my Frogbit.

Cheers,
Michael


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## erwin123 (8 Jan 2022)

Growing plants out of a hang on back filter is an alternative way of getting the 'aerial advantage' if you want some light to reach the plants in your tank. And I don't have to water my Monstera


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## dw1305 (8 Jan 2022)

Hi all, 


MichaelJ said:


> Perhaps you should rename it the Frogbit index. I wish your advice on the "preferred duckweed"


It would have been a lot easier. In <"some ways Duckweed"> (_Lemna minor_) is the <"perfect plant"> for the Duckweed Index but it also <"has some limitations">.


MichaelJ said:


> When the duckweed really gets going its really hard to get rid of... its almost out competing my Frogbit.


That is looking very healthy,  plenty of nutrients in that tank. We may <"have a solution to your Duckweed removal issues">.

cheers Darrel


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## dw1305 (8 Jan 2022)

Hi all, 


Stan510 said:


> Monstera prices have shot up in the last couple of years


They <"certainly have">. 


Stan510 said:


> I had a few stolen that were part of a old group of stems in my yard.
> City life.


It is a shame, I used to belong to a <"Cycad growing group"> and about a third of the posts were to do with theft.

cheers Darrel


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## dw1305 (8 Jan 2022)

Hi all, 


Stan510 said:


> One thing I might be harping on in the future is highly aerated aquarium water supercharges the bacteria in the filters and that seems to really polish the water clarity with no increase in filter or pump.


It is used a lot in <"waste water treatment"> in the <"activated sludge process">.


dw1305 said:


> ..... The prime metric in nitrification isn't actually the ammonia concentration, it is the dissolved oxygen level. As you have water with greater amounts of organic pollution its Biochemical Oxygen Demand (BOD) increases, BOD values range from clean water at below 5 mg/l dissolved oxygen up to about 600 mg/L in raw sewage. Water is fully saturated with oxygen at about 10 mg/L, so you can see that you would need to continually add oxygen for nitrification to occur......



cheers Darrel


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## dw1305 (8 Jan 2022)

Hi all, 


jaypeecee said:


> We appear to have dismissed lighting as a potential inhibitor of nitrification in aquaria. Have I missed something?


I couldn't find anything specifically for the microbial assemblage that occurs in aquarium filters. I think the answer looks to be that the nitrifying bacteria are inhibited by light, but that it probably doesn't have much effect, because the bacteria are effectively shielded within biofilms. 

cheers Darrel


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## Nick potts (8 Jan 2022)

dw1305 said:


> Hi all,
> 
> I couldn't find anything specifically for the microbial assemblage that occurs in aquarium filters. I think the answer looks to be that the nitrifying bacteria are inhibited by light, but that it probably doesn't have much effect, because the bacteria are effectively shielded within biofilms.
> 
> cheers Darrel



I would think that light inhibition would be inconsequential in aquariums. If you look at a lot of marine reef tanks for example, they rely on the biofiltration taking place on mostly exposed live rock, this rock is usually exposed to very high par and light in the UV spectrum but it doesn't seem to affect filtration.


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## Matti (8 Jan 2022)

dw1305 said:


> Hi all,
> 
> You are talking <"to the converted">, I'm a <"Frogbit obsessive">, but it was Diana Walstad's <"aerial advantage"> that led to the <"Duckweed Index"> and eventually _Limnobium laevigatum_ as my <"preferred "Duckweed">.
> 
> cheers Darrel


I see Frogbites as an alternative to massive water changes. You can dose ferts quite relaxed as you know that the floaters are using them like crazy! The only downside is my red plants that are not so red any more. But  BBA has not returned, so Frogbites rule!


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## MichaelJ (8 Jan 2022)

dw1305 said:


> That is looking very healthy,  plenty of nutrients in that tank. We may <"have a solution to your Duckweed removal issues">.


Yes, the "duckweed index" works well for gauging nutrients levels - I am big fan!  With regards to removing the duckweed, I sort of already went down the route of making it a regular part of my maintenance routine to net every floating plant except for the pennywort and rinse off the duckweed. That keeps it somewhat in check. The duckweed came in with some other plants long ago - so they are in the tanks somewhat unintentionally.

Cheers,
Michael


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## _Maq_ (27 Jun 2022)

tiger15 said:


> For example, high nitrate and phosphate  is often associated with algal boom in natural water bodies, but not so in planted aquariums.


I find this a big mystery. Does anyone know why? Why do we so rarely encounter phytoplankton in aquaria?


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## _Maq_ (27 Jun 2022)

Matti said:


> The problem with aquariums is the lack of real data. There are a lot of opinions and believes , but few real theories or models that would have been tested, measured and published.
> The great thing in Walstads book is that she has a tried to understand what happens in a planted tank by using real data and studies, albeit from outdoor ecosystems.
> And her opinion that too strong filtration is not beneficial for plants makes sense, supported by her own experiments.


(1) Papers on outdoor ecosystems... If you truly read those papers, you'd see that many scientific experiments are performed in tanks made of glass, which are called ... hmm ... let me recall... yes - _aquarium_.
(2) I happened to read quite many of the papers Ms. Walstad added to her lists. Her selections of facts are strongly biased to support her stance. Actually, I caught her quoting a paper without context, while the paper as a whole arrived at exactly opposite conclusions. So, she went at great length to appear as a scientist, but in my opinion, she's not. (Besides, she never published any scientific paper.)
(3) Take her statements about submerged plants' preference for ammonia over nitrate. That is a gross simplification. If judged without context, then yes, taking ammonia and creating amino-acids from it is energetically less demanding. But in reality, it is subject to many other factors. pH is one among them. Nutritional status another one. Mineral content of the water is another. And light intensity is next one, and yet not the last one. The only correct answer to the question of ammonia or nitrate is - both should be available, and let each plant to choose.
(4) Have you read the list of plants which she kept in her tanks? If I were able to keep only such easy plants, I would not dare to provide advice to anyone, not to mention publishing "a scientific treatise".


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## tiger15 (28 Jun 2022)

_Maq_ said:


> I find this a big mystery. Does anyone know why? Why do we so rarely encounter phytoplankton in aquaria?


One explanation is that most environmental  studies were conducted either in waters without aquatic plants or in temperate zone where aquatic plants are seasonal.  Without active growing aquatic plants for competition, high nitrate and phosphate is naturally associated with algal bloom. If more studies were conducted in tropical waters with perennial aquatic plants, the association may not be apparent.


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## dw1305 (28 Jun 2022)

Hi all, 


_Maq_ said:


> Have you read the list of plants which she kept in her tanks? If I were able to keep only such easy plants, I would not dare to provide advice to anyone, not to mention publishing "a scientific treatise".


I'd cut her a lot more slack than that, it <"may not be perfect">, but I still think it holds up pretty well and is one of the <"most useful books"> ever published for planted aquarium keepers. 

cheers Darrel


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## tiger15 (28 Jun 2022)

Her book was the first one I read on planted aquarium. Her book sounds scientific with references supporting every one of her viewpoints.  While many concepts appear theoretically sound, they may not be relevant to glass box culture and cannot be validated in practice.  For example, her recommendation for no water change approach by listing  complete nutrient availability in fish food, waste and tap water.  In practice, it rarely works out and an invitation for algae and deficiencies except for the easiest plants like Hornwort.


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## castle (28 Jun 2022)

tiger15 said:


> Her book was the first one I read on planted aquarium. Her book sounds scientific with references supporting every one of her viewpoints.  While many concepts appear theoretically sound, they may not be relevant to glass box culture and cannot be validated in practice.  For example, her recommendation for no water change approach by listing  complete nutrient availability in fish food, waste and tap water.  In practice, it rarely works out and an invitation for algae and deficiencies except for the easiest plants like Hornwort.



To be fair to it, Hornwort is quite a nice plant.


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