# High water turnover - discuss :)



## Matt Holbrook-Bull (18 Jun 2008)

Due to this subject cropping up on lots of other threads I thought Id start a proper thread for it, so we can hammer it out!! *nudge Clive*   

The subject is filtration and high turnover.. 

Back in the old days a few years ago, Tom Barr was advising low turnover due to the fact that ferts and CO2 can get filtered/rattled out of the water column, obviously causing expense and/or problems.. this opinion seems to have changed over the time as the hobby has  progressed and we've all learned more about how things work.

My point is this... Due to the obvious need for good circulation to provide ferts/co2 to any plant in the tank, a high flow rate is obviously desirable.  But, surely the answer isnt to increase the size of your filter.. surely its better to add power heads to the tank to get the same effect?  I realise these are ugly things, but they can be hidden almost anywhere with decent scaping.

Anyway.. thoughts and different experiences most welcome


----------



## ceg4048 (18 Jun 2008)

Hiya Matt,
               Yeah, powerheads can help quite a bit - there's no denying it whatsoever, but haven't you noticed the trend towards removing things from the tank and to reduce clutter in the tank - inline heaters, inline diffusers, glass pipework etc? This aesthetic movement is away from clunkiness and towards a more streamlined and minimalist look.

Once you determine how much extra circulation you need then you have to pick the right size powerhead, and that can be unsightly. Remember we talked about how to achieve various flow patterns as well? It isn't just the added flow throughput but the circulation lines to eliminate dead spots, so this means you have to really get creative about how and where you position the pumps. That means that now your aquascaping has to encompass the geometric solution of fluid dynamics as well as art. No thanks.   Have you seen Barrs latest 180G effort? It looks fantastic until your eyes wonder over to the rocket propelled grenade launcher on the left, ugh...http://www.barrreport.com/general-plant ... ar-13.html

That does illustrate however how committed he is to flow and I believe if you read through the thread his total flow is a massive 4000 LPH. The larger the tank the more committed you need to be about flow. CO2 becomes more problematic as tank size increases but is important in all sizes.

The other thing to consider is that the bigger the pump rating of a filter the more filtration you have. More biomedia means more bacteria and that means better NH4 control. We should be committed to getting NH4 outta there as quickly as possible especially if the tank is highly lit.

I've use lower flow, powerhead augmentation and bigger filters and the hands down best solution from an algae, plant growth as well as from an aesthetics standpoint I've found is massive filtration. Remember that my tank is lit by 1/2 kilowatt of CF T5 with reflectors and sits in a conservatory open to sunlight. It is extremely well lit. The difference in algal blooms was immediate as soon as I upgraded the filtration. 

Now does this mean that you won't get algae if  you have massive filtration? Hardly - a high filtered tank is subject to the same rules, so that poor dosing or too much light or poor CO2 will cause trouble. Does that mean you can't be successful with lower flow? No, not at all, many do. What we're saying is that massive filtration is your ally. It means that if you do suffer an algae attack then it's loads easier to get rid of when the throughput is higher because you have a bigger bacterial army as well as better nutrient delivery. What it means is that you can upgrade your lighting with less trepidation because CO2 delivery is more efficient with higher flow. You can also overstock more with less fear - so there are lots of benefits of higher filtration besides the added flow. George is even more fanatic than I am. I think he follows the 20X rule...  

Cheers,


----------



## Matt Holbrook-Bull (18 Jun 2008)

Im trying to talk myself OUT of buying more stuff!!  Your not helping!!   

Yes, the aesthetic angle is a really deal breaker.. while I dont like to be led by the trends of the world there's no doubt that a tank devoid of any hardware is a more beautiful one.

Flow seems to be much more of an issue the larger you get.. back when I had a 140, it was no issue to get the flow I needed, even though it was long and narrow, not long and fat like this 235 is.  Today Ive sat and watched the tank clearing after its rescape (pictures to come I promise!) which has given me a chance to closely observe the flow patterns in the tank.  Its rare you have the turbidity to see it clearly enough, and there are dead spots.. even with the spareness of a newly planted scape.  

Ive moved the power head around to point the other way and now I have a nice 'sway' on everything.. but I worry as things get bigger that that will reduce.

And yes, boy does Gerryd have some serious flow going on in that tank.. its a wonder he keeps anything rooted!! To me thats overkill and no mistake.

I wont have the wedge for a new filter until end of the month anyway, so thatll give me a chance to observe the growth differences now Im using AS before I inevitably fork out another Â£150 on this pile of water in my living room!

Still be interested in anyone elses opinions though as a matter of discussion, especially your's George and Dan.


----------



## aaronnorth (18 Jun 2008)

Also too add, why spend moner on just extra flow when you can have filtration aswell? Say you get a cheap powerhead like the maxi-jet 400 http://www.warehouse-aquatics.co.uk/max ... -145-p.asp for Â£13, why not spend this on flitration? If we look at the fluval 05 series, this Â£10 can get you the next size filter up which means more filtration and flow (100l)


----------



## Matt Holbrook-Bull (18 Jun 2008)

aaronnorth said:
			
		

> Also too add, why spend moner on just extra flow when you can have filtration aswell? Say you get a cheap powerhead like the maxi-jet 400 http://www.warehouse-aquatics.co.uk/max ... -145-p.asp for Â£13, why not spend this on flitration? If we look at the fluval 05 series, this Â£10 can get you the next size filter up which means more filtration and flow.



youre not helping either!!!!


----------



## Garuf (18 Jun 2008)

If you can track it down Tom posted a series of photos showing the same stretch of river in high to low levels of flow, even in nature low flow = algae, and you've guessed it plants out in the fast flowing area, devoid of any algae.
I'm an advocate of what was previously considered over filtering but there has to be a stand point where there is simply too large a filter. 
I'm about to set up a fx5 for my 15gallon tank (anyone know where I can get cheap filter media? pm me), it can go 2 ways, disaster or success I think the benefits of high flow are clear to be seen especially when you consider that you will have items inline that will limit the flow anyway.


----------



## JamesM (18 Jun 2008)

I've still got a copy of PFK where they warn higher turn over causes algae


----------



## George Farmer (18 Jun 2008)

Hi Matt

For the record, I think the filtration, flow and circulation 'new-school thinking' is one of the biggest developments in the hi-tech planted tank hobby, behind CO2.

Bigger is better, simple as that.

20x turnover rule is good for me for smaller tanks under 100 litre.  10x for bigger tanks.  Jeremy Gay and I joked about this actually.  One should not go for the 10x turnover rule, but the 10x rated rule i.e. a filter rated for a 1000 litre tank should be used for a 100 litre tank.

I think it's also important to combine the good flow and circulation with good biological filtration to further help minimise potential algae isssues.  So I'd always opt for bigger and better filters, over filter+powerhead.

BTW I've had good results with less i.e. Juwel internal filter.  But this was low light and I highly suspect that with high lighting etc. then it wouldn't be enough.  And that's a very important point.  In lower lit tanks, the importance of getting all the CO2 etc. around the tank isn't as important. 

So Matt, what would I do in your tank?  Probably have 2x big externals with a combined rated flow of around 2400+lph.  



			
				JAmesM said:
			
		

> I've still got a copy of PFK where they warn higher turn over causes algae


Those were the days.  Well, the days before some jumped-up, over-enthusiastic geek called George Farmer came along and preached about the 'dark arts' of NPK dosing etc.


----------



## milla (18 Jun 2008)

Agree totally with Clive & George the more circulation the better.
I was skeptical when i first read some of the posts by Clive.  
I was having trouble dealing with GSA at the time and decided to give it a go. I added a second Tetratec  1200 to my 180l tank  (overkill i know). But the change in the tank within 2 weeks of adding the extra filter was astounding.  GSA gone, foreground plants really took off, this was one area i had really struggled in.  The stems and crypts in the tank look healthier  and grow faster than before. 
I changed nothing except the extra filter,  No changes to co2 or dosing. Water never been as clear either. 
Though it did take a day or two for the fish to peel themselves off the back wall.


----------



## ulster exile (18 Jun 2008)

I like the idea of overfiltering, not just because of the additional redundancy you could build into your fishkeeping by having an extra filter (if you choose this method) but because I do worry about not being able to rely on the flow of water around the tank.

On my 200l, I have to date run one 2026 (950lph if you believe Eheim) and have just bought a new 2026 to run on the other side of the tank.  It was only through some of the filtering discussions on this site, that my eyes were opened to the differences between the advertised flow rate and the actual flow rate with filter media/head height included.  I realise that if one assumes that you may only achieve half of the advertised flow rate, I'm still only doing 5x turnover by running both, then at the least I will have achieved a better flow of water, nutrients and CO2 through the tank and increased my biological/mechanical filtration whilst we're at it.

My only real concern is the fish.  My fish in the little tank are much more subdued with a stronger filter and I'm picking up some fish at the weekend who prefer slower flow so I will have to see how it goes!

On a side (and slightly smug) note, my second 2026 was bought BNIB as a second from Zooplus for Â£37.50 plus postage.


----------



## Matt Holbrook-Bull (18 Jun 2008)

Chrisi! I missed you 

ok ok ok.. Ill buy a new filter!

so.. next question.. Â£150, which one?  I can get an FX5 for bit less than that.. but the big Eheims are going over.. advice please!


----------



## Garuf (18 Jun 2008)

Ehiem fx5's are HUGE, and as far as I can tell they'd be perfect for your set up.


----------



## a1Matt (18 Jun 2008)

Matt Holbrook-Bull said:
			
		

> so.. next question.. Â£150, which one?  I can get an FX5 for bit less than that.. but the big Eheims are going over.. advice please!



Just a thought... You could buy two Tetratec 1200's for Â£150  :!: or just one if you want to save some money 
I bought one a couple of months ago and the only downside is that it is not silent. Although saying that I am now used to the hum and don't hear it anymore.


----------



## Ed Seeley (18 Jun 2008)

Well I'll stick up for the powerheads here.  The aesthetics are the problem, but I don't mind that as mine is tucked at the rear top corner.

However I wouldn't use a normal powerhead but one of the flow pumps.  They have much broader flow patterns that move a lot of water in a more gentle way while keeping detritus and CO2 bubbles in suspension long enough for the filter to get the dirt or for the CO2 mist to dissolve.  Mine also doesn't blast my fish or shrimps around the tank too much; in fact the Blueyes love playing in the flow.

As to Biological filtration, the limiting factor on bacterial growth is almost certainly nutrients (in this case ammonia) in well filtered tanks, not the area of biological media!  If you have the same bioload and add twice as much media the competition in the biofilm at any one point may reduce allowing a wider range of microbiological fauna, but they won't start assimilating more ammonia as there won't be any more to feed any more bacteria.  I think the simple fact is that larger filters may improve mechanical filtration but there is a limit to biological performance based on the nutrients supplied.  Using a media that promotes a wider range of fauna by giving a roughened, variable surface will improve filtration by allowing better establishment of the biofilm.  Once a good biofilm is established then it is very resilient too.

I can't see a mechanism where it would increase the rate of uptake of Ammonia, except for the fact that the improved turnover will get the ammonia into the filter more rapidly.  I can't see it making that much difference to be honest.


----------



## LondonDragon (18 Jun 2008)

I added a powerhead to my tank and its doing the trick, its really a small internal filter which as a sponge and all, works pretty well for my size tank and since then I haven't had any more problems, things just grow like weeds. Its well hidden behind the plants and you can't really see it unless you go looking for it as you probably can see on the photos from my tank.
I will replace my external eventually but I will wait until it breaks or something like that.


----------



## JamesC (18 Jun 2008)

Ed brings up some interesting ideas on the biological side of things which I totally agree with. Going against what is commonly suggested I think that adding 2 large filters on a tank is just a tad overkill. A single good filter will more than adequately deal with the tiny amounts on ammonia that are created in planted tanks. They are designed with much heavier bioloads in mind. Have a sudden ammonia spike and I would think that a single filter would probably deal with it very nearly as quick or as quick as 2 or more filters.

IMHO stable low levels of ammonia are no big deal and don't cause algae as is commonly suggested. Many people dose ammonia products daily with great success. I've dosed urea daily for 2 months and noticed no algae whatsoever. Those of you who dose Tropica Plant Nutrition Plus are dosing ammonium nitrate. All the other commercial nitrogen products that I know of also contain urea or ammonia compounds.

Flow is a different thing and is very important in a heavily dosed, high light and high CO2 tank. Adding more filters to add flow is fine or you can save your money and use pumps.

I'm sure many will probably disagree with me.
James


----------



## ceg4048 (19 Jun 2008)

James/Ed,
                 I've thought about your points and while they do seem reasonable, they bring up more questions than they answer. Now, remember my arguments are based on premise that NH4 + light cause algae. If you don't buy that premise then the arguments are not valid.

James, I remember that urea experiment you did and Barr brought up the strong possibility that the filter and sediment bacteria were reducing the ammonia in the urea via enzymatic action of urease. That would mean the bacterial reaction to NH4 is very quick, and that suppression of NH4 spikes are attributed to rapid nitrification.

I guess I also disagree with the assessment that "...tiny amounts of ammonia..." are produced in a planted tank. I would argue that the ammonia production is high and is constant simply by virtue of metabolism. Just consider the amount of ammonia generated during a tank cycling. That ammonia production rate never stops, and in fact it accelerates when we add plants and animals and food. It's just that we measure a low concentration level because the NH4/NO2 is being processed. Barr brought up the point in that thread that if you thought ammonia production in a tank was low, all you need do is to turn off your filter for a while and see the results.

All we have to do is to look at our empirical evidence. How many reports are there of algal blooms in a planted tank? Algae has become almost a central theme. A contributing factor? Ammonia production not attenuated by the available bacterial colonies. So what you say is true, that low stable levels of ammonia keep the blooms at bay but _how_ does one achieve low stable levels? Its certainly not stable when one feeds the fish for example. Metabolic rates and organic waste decay are not really all that stable as the plants grow or are trimmed, or when water is changed. I would argue that an aquarium is the least stable aquatic environment known to man. If sintered glass media or sponges function as we think they do, by making space available for hosting bacteria, then more space means that a rise in NH4 allows these germs to increase their population more easily. If less space is available would this not affect the rate of bacterial population increase necessary to consume an NH4 spike?

We observe that detritus and organic waste buildup stifle a filter by blocking the pores of the media reducing the bacterial population. Detritus sitting in the filter breaks down into ammonia which fails to be processed by the colony. The result is often BGA if filter maintenance is not performed. It seems obvious to me that if you have more filter capacity to begin with the likelihood of this condition is reduced. Maintenance is still required, obviously but you have more biomedia and space to begin with so the effect is lessened and your margin of error is widened.

I also don't buy the assumption that bacterial populations are necessarily limited by NH4 availability. Of course this could be the case under certain conditions but we really haven't measured populations versus NH4 concentration so this would be speculative. Also it's not certain that all the NH4 in a volume of water is removed during a single pass though the filter. So if I connect two filters in series this assumption would mean that bacteria colonies would be established in the first filter and not the second. Clearly, while the available space is not completely filled in both filters the available space represents a potential that affects the speed at which the population can increase. This population agility allows absorption of ammonia spikes which occur constantly.

Again, I refer to the urea thread in which Barr referenced a list of K.R. Reddy journals. Further investigation reveals that bacteria, like plants and animals require more than just Nitrogen to prosper. They require Carbon and Phosphorus as well as other ingredients. So a bacterial population could easily be limited by the availability of other nutrients. Like Nitrogen the other nutrients must be in the right form for them to digest. Some bacterial species can obtain their nutrients in a variety of forms (i.e. organic and/or inorganic) or they can use substitute elements for their biological processes, such as Sulfur in lieu of Oxygen. Other species are less agile and suffer die off if their specific needs aren't met.

We all agree that flow is definitely King, but I view the extra filtration capacity as a "shock absorber" that processes ammonia spikes which helps to suppress algal blooms. It is difficult to quantify though how much of one's success is due to the extra flow versus the extra filtration capacity. :? 

Cheers,


----------



## Matt Holbrook-Bull (19 Jun 2008)

that FX5 is colossal.. rated at 2300lph Loaded, and 3500 unloaded.. mental.


----------



## ceg4048 (19 Jun 2008)

Yes, but you'll never see that flow rate in real life, especially if you fill it with biomedia.

I should add that the only _real_ thing I have against powerheads is their lack of aesthetics. As mentioned, they _ are_ a much cheaper alternative and if you don't mind the looks, or if you have a clever way to hide them then they give you a lot of flexibility as you can point them in whatever desired direction. In the final analysis if economics forces you to choose between healthy plants with ugly thunderball jet packs versus less healthy plants with clean tank lines, well, go for the jet pack... 8) 

Cheers,


----------



## aaronnorth (19 Jun 2008)

> In the final analysis if economics forces you to choose between healthy plants with ugly thunderball jet packs versus less healthy plants with clean tank lines, well, go for the jet pack...  8)



nice summary lol


----------



## Wolfenrook (20 Jun 2008)

I can see the merits in both methods, and at the end of the day our aim is to combine good circulation with large biological capacity is it not?

Now Clive argues that this is best achieved by using a filter with a high flow rate, in my experience this is not always the case however, there are a lot of external filters out there with really powerful pumps but absolutely tiny capacities!  My last filter for example!  It was a Sicce Genio2 with a rated flow of 700lph, which is identical to my current filter, however it had a tiny media capacity!  My current filter is a JBL Cristal Profi 250 (yes I would have liked the 500, but space and money didn't permit at the time, I operate on quite a low budget most of the time) which also has a rated flow of 700lph but I managed to fit the entire quantity of biological media from my old filter into just 1 of the 3 baskets in it!!  So high flow does not always equate to large volume, especially at the lower end of the market.

My filter has absolutely great media volume, but not so great turnover, so this is where pumps/powerheads really shine!  As already noticed they are considerably cheaper than larger filters, especially if you already own a filter and are looking to upgrade the flow!  Now I quite happily admit that in my tank the circulation from my JBL would be nowhere near adequate, but pumps come to the rescue here!  I currently have a fluval 2 (that I have owned for many years) loaded with filter wool only at the opposite end to my filter outlet, pointed towards the front glass.

I get very little algae growth, and excellent plant growth.

Oh and one thing I would say if using very large filters with high outputs, I should think that you need to make sure that this output isn't coming all from one outlet.  So perhaps important to make sure that newbies don't go plonking an Fx5 on their 180 litre, and then putting jet outlets onto it!   Surfs up! lol

As to aesthetics, I don't really notice my little Fluval 2 much once the plants grow in.  On a more minimalist 'scape' though I can easily see why some people wouldn't want all that kit in there.  As to the tren for using inline kit, sure some of the poeple are buying this for aesthetic reasons, but I would bet that an awful lot are buying it to be 'fashionable'.  Planted tanks are currently all the rage, so it's only natural that this bit of the hobby will get it's fair share of 'fashion victims'.

Ade


----------



## Matt Holbrook-Bull (20 Jun 2008)

hehe surfs up indeed!

Im aiming to upgrade to an FX5 and rig up something to split the flow between a full lateral spray bar, and another outlet washing down the back wall, or something similar.. that way it should lesson the ferocity and provide a good mixing action, will see how it goes.


----------



## Dave Spencer (21 Jun 2008)

I won`t allow any hardware in to my tanks that will dictate where I have to aquascape to hide them.

When I set my tanks up intitially, I always have high light, turbo growth and be able to grow anything from an unresticted plant list in mind. With this, and the fact that I love my fast growing stems, I look to keep filter media down to a minimum and turn over to a maximum. I have never cycled a tank or witnessed any ammonia or nitrite. One thing I don`t underestimate with my turbo growth biomass is their performance in keeping the water column safe for my fish.

Using in line CO2 reactors is a pain, because I find they can restrict flow considerably. I have recently upgraded my 60l to a Tetratec 700.

Dave.


----------



## Ed Seeley (23 Jun 2008)

ceg4048 said:
			
		

> James, I remember that urea experiment you did and Barr brought up the strong possibility that the filter and sediment bacteria were reducing the ammonia in the urea via enzymatic action of urease. That would mean the bacterial reaction to NH4 is very quick, and that suppression of NH4 spikes are attributed to rapid nitrification.
> 
> I guess I also disagree with the assessment that "...tiny amounts of ammonia..." are produced in a planted tank. I would argue that the ammonia production is high and is constant simply by virtue of metabolism. Just consider the amount of ammonia generated during a tank cycling. That ammonia production rate never stops, and in fact it accelerates when we add plants and animals and food. It's just that we measure a low concentration level because the NH4/NO2 is being processed. Barr brought up the point in that thread that if you thought ammonia production in a tank was low, all you need do is to turn off your filter for a while and see the results.



As I biologist I draw the analogy to a Tropical rain forest with a healthy planted tank - Lots of nutrients locked up in the plant mass, but small amounts detectable free as the plants rapidly assimilate it.  There is a distinct possibility that bacteria are outcompeted for nutrients at times by the plants assimilating the ammonia as well as the factor that other nutrients may at time limit bacterial growth such as oxygen.



			
				ceg4048 said:
			
		

> All we have to do is to look at our empirical evidence. How many reports are there of algal blooms in a planted tank? Algae has become almost a central theme. A contributing factor? Ammonia production not attenuated by the available bacterial colonies. So what you say is true, that low stable levels of ammonia keep the blooms at bay but _how_ does one achieve low stable levels? Its certainly not stable when one feeds the fish for example. Metabolic rates and organic waste decay are not really all that stable as the plants grow or are trimmed, or when water is changed. I would argue that an aquarium is the least stable aquatic environment known to man. If sintered glass media or sponges function as we think they do, by making space available for hosting bacteria, then more space means that a rise in NH4 allows these germs to increase their population more easily. If less space is available would this not affect the rate of bacterial population increase necessary to consume an NH4 spike?



I think a key factor in a lot of algae outbreaks is a lack, or reduction, of maintenance.  It's easy to say that this is ammonia, but there will be lots of other organic molecules floating around too - maybe those are a trigger too/instead?

I don't really think it's the space per se that's the real benefit of sintered glass material.  I think the texture allows a range of micro habitats within it that allow a wider range of microbiological life that means the filter is better equipped to deal with all sorts of changes, whether that's nutrient levels or other problems.

As to space there will be more preferable sites for certain fauna to proliferate and they will be the real estate that is in demand and therefore more highly populated.  Huge amounts of media will probably be under occupied as there isn't anything for them.  Whether all the nutrient is used in one pass or not really isn't the issue and wouldn't necessarily indidcate limitations as some nutrients will pass through in area without contacting the biofilm regardless of filter size.  

Bacterial colonies will form a denser biofilm and this can be thicker or thinner depending on the limiting factors to bacterial growth so you only need enough space, not lots of spare space IMO.



			
				ceg4048 said:
			
		

> We observe that detritus and organic waste buildup stifle a filter by blocking the pores of the media reducing the bacterial population. Detritus sitting in the filter breaks down into ammonia which fails to be processed by the colony. The result is often BGA if filter maintenance is not performed. It seems obvious to me that if you have more filter capacity to begin with the likelihood of this condition is reduced. Maintenance is still required, obviously but you have more biomedia and space to begin with so the effect is lessened and your margin of error is widened.



But isn't the same amount of detritus going in regardless?  Surely the last thing you want is it sitting in a large filter producing ammonia?  Best to remove it ASAP.  
And why will blocked pores reduce the bacterial population?  They may decrease one type but another will take over as long as areas don't become anoxic and this will only happen if the filter isn't maintained and a larger filter may lengthen this time.  Surely it's better to have a smaller filter and clean it more often to remove the detritus and therefore the soruce of ammonia?



			
				ceg4048 said:
			
		

> I also don't buy the assumption that bacterial populations are necessarily limited by NH4 availability. Of course this could be the case under certain conditions but we really haven't measured populations versus NH4 concentration so this would be speculative. Also it's not certain that all the NH4 in a volume of water is removed during a single pass though the filter. So if I connect two filters in series this assumption would mean that bacteria colonies would be established in the first filter and not the second. Clearly, while the available space is not completely filled in both filters the available space represents a potential that affects the speed at which the population can increase. This population agility allows absorption of ammonia spikes which occur constantly.
> 
> Again, I refer to the urea thread in which Barr referenced a list of K.R. Reddy journals. Further investigation reveals that bacteria, like plants and animals require more than just Nitrogen to prosper. They require Carbon and Phosphorus as well as other ingredients. So a bacterial population could easily be limited by the availability of other nutrients. Like Nitrogen the other nutrients must be in the right form for them to digest. Some bacterial species can obtain their nutrients in a variety of forms (i.e. organic and/or inorganic) or they can use substitute elements for their biological processes, such as Sulfur in lieu of Oxygen. Other species are less agile and suffer die off if their specific needs aren't met.



Whether it's ammonia or some other nutrient that limits the bacterial growth, it certainly can't be space in an established biofilm as the bacteria will also be colonising every other surface so why add more filter capacity?  


I've been thinking long and hard about this whole idea in reference to my koi pond and trying to apply some of the ideas from there to planted tanks.  While many things are different and some ideas do not translate the basic principles in both are completely sound.  The biggest factor in effective biological filtration in a koi pond is not size as such but the oxygen present in the filter.  The two most effective filtration methods used in new ponds tend to be either fluidised bed filters where a slightly bouyant media is kept in suspension by large quantities of air bubbling through it and a shower type filter using ceramic media where very large amounts of water at high turnover rates are chucked over the filter.

Both work well as they do a number of things;
Neither settle out any detritus in the filter (the fluidised filters need a static bed to act as a strainer and the Showers simply process the waste thanks to their special ceramic media - don't ask how!!!).
They keep large amounts of oxygen in the water to allow large amounts of aerobic respiration.
They use a relatively small amount of media but use it very effectively and produce a range of niches where different microorganisms can flourish.

When you compare the amount of waste these filters have to process compared to that in a planted tank then it's stratling to me that we worry about adding extra filters.  I think if our filters' turnovers were up to the job then we wouldn't need to worry about adding anything extra.

I don't think an extra filter can possibly hurt, but I really don't think they're usually necessary either.


----------



## JamieH (25 Jun 2008)

Ed Seeley said:
			
		

> I don't think an extra filter can possibly hurt, but I really don't think they're usually necessary either.


ther


There's a couple of other points though...

What of asthetics? Crystal clear water in a display tank is attractive - larger / more filters aide in this. Also, taking more particulate matter out of suspension surely helps light penetration in the tank, too.


----------



## Ed Seeley (26 Jun 2008)

JamieH said:
			
		

> Ed Seeley said:
> 
> 
> 
> ...



But if your filter has a turnover of 4 times the tank's volume anyway then it only takes 15 minutes for all the tank's water, on average, to be passed through the filter.  If your filter isn't removing fine particulate matter then the flow rate is either too high and fine particles aren't settling out in the filter or you need to use filter media that filter out smaller particles like floss or or JBL Symec Micro.  You don't need huge turnovers through a filter to do that.


----------



## plantbrain (27 Jun 2008)

I do not think I ever told anyone to do lower flows etc in the past. I've always been a strong advocate of over filtration and higher flow rates.

It's just thinking about it in the context of CO2 and mixing and reduction of flows due to the thick plant beds as they grow and fill in a tank are newer concepts I've raised to the attention of hobbyist.
Fish can get lazy and fat, much like us if they do not swim a lot, they will eat better, behave better etc also.

Steve and George Lo at AquaForest also over filter, 20X turnover is good.
Dupla long ago suggested high good current as well.

I have not 4000 lph, rather, 3.785X that, 3000 gph.

1000gph from the Filter, 2000 from the powerhead, I have 2 of them, but then reduced it back to 1 because the plants swayed in a manner that bugged me and it was a bit too much.

I use powerheads for added flow and a nice rippling like in the ADA photo's(he just does that for effects for the photo with a hair dryer). This allows good directed flow and good surface movement with minimal eletrical cost.

Ed, I think you and the rest of the folks here are on the right track.
The NH4 is locked up in biomass and is rapidly cycled to another critters, plant, bacteria etc.

When growth wanes, then we see more NH4 backed up, we see higher CO2 and lower O2(unless low CO2 caused this, then you know and can predict the mess from there.......).

Plant cuticles are made most of esterfied C16-C18 molecules which require a lot of reduced Carbon, no carbon, plants stop making it and use the reduced carbon for more essential functions.
Algae then can easily grow on the surfaces.

"What induces algae" needs to be a focused question.
It does relate to plants etc, but keep it on it's own.

Ask yourself if you where an algae spore, what signals would allow you to grow, bloom, and repduce sexually and produce more spores for the next season?

Plants are just vegetatively growing massive weeds.
There's no sexual phase to 99.99% of folks' horticulture methods. 
All clonal cuttings.

Germination occurs in algae much like plants. Temp, CO2, O2, intensity of light, duration of light, NH4, current(which relates to CO2/O2). I have not found much else.

Regards, 
Tom Barr


----------

