# Walstad revises



## Soilwork

I've read on a few forums now that D.Walstad now advocates water changes and filtration? And the lack of is what is causing problems in some cases but I am yet to find any direct quotes from Diana herself.

Does anybody know where this was said/stated? I don't want to become a victim of regurgitation without having seen the original text.

Thanks


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## dw1305

Hi all,


Soilwork said:


> I've read on a few forums now that D.Walstad now advocates water changes and filtration? And the lack of is what is causing problems in some cases but I am yet to find any direct quotes from Diana herself.
> 
> Does anybody know where this was said/stated? I don't want to become a victim of regurgitation without having seen the original text.
> 
> Thanks


(Inactive) UKAPS member "@Ghosty" had a conversation with Diana, here <"Talking with Diana Walstad....">, there is also an interview on <"Aquariss.net">, where she specifically mentions water movement.


> .....I have filters or aerators to  create mild water movement. This speeds up decomposition and the recycling of fish wastes into plant nutrients and CO2.


cheers Darrel


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## Soilwork

Thanks for the links.  It's still not clear cut in these posts about water changes in general.  Perhaps when first laying the soil that's a given.

I was under the impression that she had changed her opinion on water changes but it seems that this is not the case.  I think she has always encouraged water movement but not much aeration.  

I think I failed because I had little flow, little aeration, little oxygen and failing plants.  I would lose a fish every few weeks.


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## dw1305

Hi all,
She mentions water changes in "_Small Planted Tanks for Pet Shrimp_" on page 9. 





> My DSM tanks require more maintenance than the bowls. They are move vulnerable to algae.
> 
> I had to change water at least once every week during the first 6 weeks following submergence. Occasionally, I had to remove small algae mats (using a toothbrush) that threatened to spread over the plant carpet.
> 
> However, I noticed that the algae retreated considerably once the Frogbit started growing well. I continue with biweekly water changes and thinning out excess Frogbit.


Cheers Darrel


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## alto

She did some interviews on sites that are no longer active ... I don't recall where I read the discussion(s); as you may be aware, she experienced mycobateriosis in her rainbow fish populations (eventually she shut down & sterilized tanks), she felt that lack of water changes may've contributed & began to advocate water changes ... I don't recall the details
I've not read new editions of her book  




Soilwork said:


> I think I failed because I had little flow, little aeration, little oxygen and failing plants. I would lose a fish every few weeks.


In theory, the plants will provide oxygen - there are planted tank water column measurements where water is "supersaturated" with oxygen, & even initial photoperiod measurement show good oxygen levels

I never felt comfortable with the concept of no water changes on a system with livestock - there are too many variables, especially when first starting out


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## Soilwork

Cheers to both.  

Alto.  You are correct however, in order for plants to produce oxygen they have to be photosynthesising and in my case they were just dying.  I had a severely underpowered filter with little aeration, a freshly submerged soil with little water changes and poor plant health.


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## dw1305

Hi all,





Soilwork said:


> You are correct however, in order for plants to produce oxygen they have to be photosynthesising and in my case they were just dying. I had a severely underpowered filter with little aeration, a freshly submerged soil with little water changes and poor plant health.


I  think this is one reason why floating plants (usually _Eichornia_ or _Pistia_) are used for <"phytoremediation">, they have access to atmospheric gases.

cheers Darrel


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## PARAGUAY

It just goes to show a well respected person like Diana Walsted can prove that despite the science,experience etc that nothing is permanent and it's truly refreshing to validate us all from experts to hobbyists to question things,try things and learn more ,Everything is always evolving


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## dw1305

Hi all, 





PARAGUAY said:


> It just goes to show a well respected person like Diana Walstad can prove that despite the science,experience etc that nothing is permanent and it's truly refreshing to validate us all from experts to hobbyists to question things, try things and learn more


That is it. 

Experiments have shown that your original theory wasn't quite right, so you develop a new theory, if possible one that you can test empirically. It is how science moves forward.   

If some-one can prove that the speed of light isn't absolute then all the laws of physics are wrong and we have to start again. It is Karl Popper's <"Philosophy of Science">, because the law that states that the speed of light is absolute is falsifiable.

The problem in Ecology is that there aren't any laws, it is nearly all conjecture (see <"Thomas Kuhn">), so we are into the realms of consensus and <"probablility">, and probability is an area where a lot of people (including many scientists) struggle.

cheers Darrel


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## Soilwork

You are both quite right.  I have lost count of the amount of times I have read her book or picked it up for quick reference.  I was an avid believer in her approach as a more natural means of system stability appealed to me and was logical.

There were probably a multitude of reasons that this didn't work for me.  I have been in the shadows for quite some time before I joined this forum and as a result I am well aware of the importance co2 plays in underwater plant growth and the importance of oxygen in this system and what is means when there is a lack of.

To be fair I was probably trying plants that are just not cut out for the method because ethe Anubias and crypts did pretty well. 

The carbon subject was the one I was looking forward to covering in her book but I quickly found that it was the weakest. 

If I was to use soil again (just dug it all out) I would mineralise it and have a lot more flow and do bi-weekly water changes.  I would have a nice ripple up to to reduce biofilm accumulation and choose more plants that are suited to the environment.  Most of my plants died and I would lose fish regularly.  Since then I have gone down the injection route with EI.

I would like to try the low tech approach again knowing what I know now.  Maybe in the future.

Edit:  the point of this thread was to clarify that what I had been advising people with regards to D.Walstad rethinking things was accurate.

I'm still not convinced she would wholeheartedly say that her method needs revising, especially if other have success.  After all, at what point does it stop being the Walstad method and just a regular low tech approach if these changes were to be implemented?


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## Manisha

I've really enjoyed reading this thread because I maintain a low tech aquarium but wouldn't feel comfortable with few water changes or topping up. Although the traditional Walstad tank is achievable (I immediately think of Big Tom's Bucket of Mud) I think very few people would be able to maintain a balance between basic inputs & outputs. In my case, choosing to keep Angel fish means the 'input' is high & would have to be very on point with my outputs wrt filtration & plant choice or increase my tank volume & plant mass. I think its important to remember a fish tank is a closed system in comparison to what occurs in nature & I think it would take a great deal of experience to achieve this without water changes.



dw1305 said:


> Hi all, That is it.
> 
> Experiments have shown that your original theory wasn't quite right, so you develop a new theory, if possible one that you can test empirically. It is how science moves forward.
> 
> If some-one can prove that the speed of light isn't absolute then all the laws of physics are wrong and we have to start again. It is Karl Popper's <"Philosophy of Science">, because the law that states that the speed of light is absolute is falsifiable.
> 
> The problem in Ecology is that there aren't any laws, it is nearly all conjecture (see <"Thomas Kuhn">), so we are into the realms of consensus and <"probablility">, and probability is an area where a lot of people (including many scientists) struggle.
> 
> cheers Darrel



Great links - took me a while to read. I find these ideas & theories facinating. I think we build ourselves on ideas (& forget they are ideas) & as we age, this worsens!  Because the building block we started with holds many others. However we look towards older more experienced folk (perhaps more set in their inaccurate ways?!) Rules & models...


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## dw1305

Hi all, 





Soilwork said:


> I'm still not convinced she would wholeheartedly say that her method needs revising, especially if other have success.


I'd have to say straight away that, despite having some reservations about the lack of water changes etc, I still think her book is an absolutely fantastic resource, and no-one else has attempted to write a book with similar scope or scientific rigour. 

I'd also recommend <"The "Optimum Aquarium" by Horst and Kipper">, I only <"read it recently">, following a recommendation on this forum (it was published in the 1980's). 





Manisha said:


> Although the traditional Walstad tank is achievable (I immediately think of Big Tom's Bucket of Mud)


 I think tank volume, and architecture, has a considerable bearing on the likelihood of success. If I was going to have a "strict Walstad" tank, I'd make it a <"large volume, but shallow, tank">.

cheers Darrel


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## zozo

For the people who understand the German language or maybe still want to try to learn it.. This might be a very intersting source.. It's from MyFish.org it's a German radio channel/talkshow about pets and care, every thursday evening they have 1 hour about everything you like to know about aquarium.. These are interviews with people who are almost all over 30 years active in the aquatic hobby or professionaly involved in the bussines from plant nurseries, fishbreeders, fish doctors, university professors, field researchers etc. and talk about all sorts of issues encountered in aquaristic.. Some very interesting and sometimes very different theories, statements and ways of viewing are shared. Some are realy puzzling others again realy inlightening.

Here are the recorded podcasts of this radio program..
http://www.haustier-radio.de/shows/my-fishorg-aus-freude-an-der-aquaristik.html

Unfortunately only in German.. But Germany is a very big country and has done a lot in the history of aquarium hobby.. So there are many interviews with very professional people in this field.


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## sciencefiction

Soilwork said:


> I've read on a few forums now that D.Walstad now advocates water changes and filtration? And the lack of is what is causing problems in some cases but I am yet to find any direct quotes from Diana herself.



She was active on a forum called aquarium plant central. As an answer to some poster's question she mentioned her changed opinion on water movement, i.e. oxygen related. I can't remember the exact words but the idea is that decomposition of organics produces CO2 in the presence of oxygen. Lack of oxygen or low oxygen will also impact the co2 produced from decomposition, and in turn can also lead to anoxic conditions that would affect negatively both fish and plants. She initially thought that too much CO2 would degas if there is a lot of water movement but in fact the water movement is essential for the co2 production because of the better oxygen exchange.

When I set up my walstad tanks, I set them up with mineralized soil, excessive flow and plenty of surface movement. I haven't had a problem that way. I did regular water changes too. I tried with no water changes for 5-6 months at some stage during the years and it surely didn't work. The TDS of the tank shot very high, nearly doubled up in that amount of time. My plants liked it, but my fish surely didn't. Some of them got sickly during that period so the no water changes experiment ended. My tank at the time was lightly stocked.


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## zozo

That, whole no water change concept is imho something for tanks with no lifestock.. Me too i did it for a i do not even remember for how long, only topping off the water level without water changes. And this was all about 30 years ago. At that time it was very common and freqeunt water changes wasn't realy recomended in any book available for what i remember. Actualy back then, all information was rather very one-sided  and short compaired to what available nowadays.. 

In the end the chances that no water changes doesn't work is higher than the other way around, because there are some may things that can have impact on a small confined ecosystem as an aquarium. And the majority aint even visible with the naked eye and the longer you are into the process the narrower the turning point can get. The moment it becomes visible, 9 out of 10 times you are to late and there already will be damage done. 

Preventing is beter than curing..

In theory it might well be possible but in practice it stays a gamble even if you are very experienced.. And we should not experiment nor gamble with the health of our precious fish etc. ANd we certainly should not see our hobby as a sport to proof theories. 

With all respect to Diana Walstad here books are realy very interesting.. But what's in the end the point of not having the need of doing water changes?
Is it to benefit your expenses and make it cheaper? Or because the water from the tap actualy aint aquarium suitable and need a lot of work to condition it, which makes it such a hassle? (Rather lazy than tired?) 

If one of the points above is the argument.. You actualy should not have an aquarium at all and look for another hobby..  Something like a poodle maybe, also a pet you can scape with..


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## sciencefiction

He, he, zozo. Perhaps we should change the type of pets we keep. One can get a dog for example, no water changes needed and plenty of co2 for free.


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## zozo

Yes an Iwagumi poodle. Who knows it might be a commercial break through too..


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## dw1305

Hi all, 





zozo said:


> With all respect to Diana Walstad here books are realy very interesting.. But what's in the end the point of not having the need of doing water changes?


 I just think that when she had found just how effective plants were in maintaining water quality she got a bit carried away and began to see plants as an alternative to water changes rather than an adjunct. 

I was just looking at this post (on Aquatic Plant Central) <"Diana Walstad and Discus">. 





zozo said:


> And this was all about 30 years ago. At that time it was very common and freqeunt water changes wasn't realy recomended in any book available for what i remember. Actualy back then, all information was rather very one-sided and short compaired to what available nowadays..


 I think this is a very valid point, I used to <"kill my fish with sickening regularity when I started fish-keeping">. Aged, yellow tinted, water used to be looked on as a good thing, rather than as an, invariably toxic, brew. 

cheers Darrel


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## zozo

I think that in nature in what we consider small bodies of water there will Diana's theories be spot on.. But in a fishtank with in comparison only a few litres of water it is a ticking time bomb where you just might get lucky. Most of the times if it goes south it usualy goes south very hard.. And indeed if you are not among the lucky ones you probably end up with sick and dead fish.. 

But in nature it probably functions excactly the way she describes it.. If you look at the drainage reservoirs wich are dug next to the motorways and how fast such a small body of water is teeming with life with loads of plants and fish in no time brought in by the birds. And can be perfectly healthy and crystal clear for decades and only fed with rain water now and then.. I know a few 20 metres long and 8 metres wide maybe, 1 metre deep depending on the rainfall. Where i did catch beautiful fish as a kid with a net also 30 years ago and it is still there today with kids fishing in it.. 



dw1305 said:


> Aged, yellow tinted, water used to be looked on as a good thing, rather than as an, invariably toxic, brew.



Yes this indeed was the case, that i also remember from back then, the older the beter.. It even was adviced to keep your hands out of the fishtank as much as possible, like cleaning the tank was a sin. Little substarte syphoning with such an air driven sucker and filter cleaning that was it.. And if there where problems, you go to the LFS and they sell you some medicin and a bag of carbon and still nobody said do a partial water change. I remember blaming myself that it was me sticking hands in the water was making the fish sick.. It's actualy sad and hilarious at the same time, but we didn't know any beter..


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## Manisha

zozo said:


> That, whole no water change concept is imho something for tanks with no lifestock.. Me too i did it for a i do not even remember for how long, only topping off the water level without water changes. And this was all about 30 years ago. At that time it was very common and freqeunt water changes wasn't realy recomended in any book available for what i remember. Actualy back then, all information was rather very one-sided  and short compaired to what available nowadays..
> 
> In the end the chances that no water changes doesn't work is higher than the other way around, because there are some may things that can have impact on a small confined ecosystem as an aquarium. And the majority aint even visible with the naked eye and the longer you are into the process the narrower the turning point can get. The moment it becomes visible, 9 out of 10 times you are to late and there already will be damage done.
> 
> Preventing is beter than curing..
> 
> In theory it might well be possible but in practice it stays a gamble even if you are very experienced.. And we should not experiment nor gamble with the health of our precious fish etc. ANd we certainly should not see our hobby as a sport to proof theories.
> 
> With all respect to Diana Walstad here books are realy very interesting.. But what's in the end the point of not having the need of doing water changes?
> Is it to benefit your expenses and make it cheaper? Or because the water from the tap actualy aint aquarium suitable and need a lot of work to condition it, which makes it such a hassle? (Rather lazy than tired?)
> 
> If one of the points above is the argument.. You actualy should not have an aquarium at all and look for another hobby..  Something like a poodle maybe, also a pet you can scape with..



I think if you were a hobbyist but worked away from home a lot, a fishless planted tank would be a good compromise


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## zozo

Manisha said:


> I think if you were a hobbyist but worked away from home a lot, a fishless planted tank would be a good compromise



The only compromise..


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## PARAGUAY

Water changes a doddle compared to tiring this fella out


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## Soilwork

I think the main thing to consider is that nobody in the hobby goes out to purposely kill fish and although the methods of our forefathers were less than ideal, at the time we thought what we were doing was for the best interest of this fish and plants.  Sadly, that wasn't the case.

As for water changes.  I agree that even in a Walstad they are necessary but the volume and frequency is variable depending on the system in question. 

But is a tank that has a soil underlayer, good water movement and frequent partial water changes a Walstad tank anymore? 

I believe that soil is the best substrate for the plants.  It just became a hassle moving plants that eventually had had enough.  I've gone with Eco complete just for its CEC.


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## dw1305

Hi all, 





Soilwork said:


> But is a tank that has a soil underlayer, good water movement and frequent partial water changes a Walstad tank anymore?


I think it probably is. 

Her underlying concept is very much that dense planting, with some plants having the "aerial advantage", is the thing that makes tank management easier, she calls them <"Natural Planted Tanks" NPT>.  

The soil substrate provides nutrients (and a source of carbonate hardness) and also a healthy microbiological environment. This is spoken about by Stephan Tanner in <"Biofiltration">. 

cheers Darrel


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## sciencefiction

Soilwork said:


> think the main thing to consider is that nobody in the hobby goes out to purposely kill fish and although the methods of our forefathers were less than ideal, at the time we thought what we were doing was for the best interest of this fish and plants. Sadly, that wasn't the case.




I understand that sometimes we do things without meaning any bad outcome but ignorance doesn't equate innocence. We must have an open mind.



Soilwork said:


> But is a tank that has a soil underlayer, good water movement and frequent partial water changes a Walstad tank anymore?



She did popularize low tech tanks using soil as substrate so I'll keep calling it "Walstad". Any idea is open to modification. There is always a better way.


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## zozo

I think that the term Walstad tank will eventualy apply to all low tech tanks no matter what kind of substrate you use.. If you give it time enough they all end up with the same propperties.. One can go for garden or pond soil to speed up some processes where an inert substrate will take some more time to eventualy do the same thing. Inert substarte wont be inert forever it's only an inert start..

If you break down the composition of a bag of soil what do you end up with? Sand, Clay, peat, worm castings maybe some other composted vegitation with you could kinda also put into the peat category..

Then i'm not so very different with using crushed lava and small gravel instead of sand, akadama instead of mineralized clay, some peat pellets and laterite clay balls at places i planted. Now after almost a year into the process, there is a load of organics like fish and shrimp castings added too and is the substrate pretty mineralized i guess.
Only thing i did, i didn't took it premixed from a bag, mixed my own and let the tank do the job.

How do you say that in English in the end it is all tared with the same brush..


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## Soilwork

How do you suppose Eco complete compares to a soil substrate in terms of microbial development in biofilms.

I chose Eco complete for its high porosity and CEC and the fact that it doesn't need replacing.  Other than lacking the benefits of Humic substances do you think Eco complete provides a good substrate/root interface for plants and microbes?


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## dw1305

Hi all, 





Soilwork said:


> How do you suppose Eco complete compares to a soil substrate in terms of microbial development in biofilms.





zozo said:


> If you give it time enough they all end up with the same propperties.. One can go for garden or pond soil to speed up some processes where an inert substrate will take some more time to eventualy do the same thing. Inert substarte wont be inert forever it's only an inert start..


I'm with Marcel ("Zozo") on this one. 

I don't think it really matters what your original substrate is, if you wait long enough, and <"leave it relatively undisturbed">, over time it will become more soil like.

cheers Darrel


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## zozo

How does it compare, i realy do not know if there is a definitive answer to that.. If i look back at my early beginnings in the 1970's it all was very simple.. As stated above water changes where considered a sin, aquarium plant fertilization was a nonsense and nowhere mentioned.. Walking into the LFS there where only bags of washed river sand and different sizes of gravel to be found and a pile of pumice and driftwood.. There were not so many plants, we had valis, sword, shoelase, cabomba, elodea, sag, and maybe a few other easy plants.. Mosses, never heard of it, we had algae for that and it comes for free..

And still i managed to grow a huge carpets of sag and have nice large swords and shoelases etc. It worked to a sertain extend for a periode of time usauly a year for the lucky ones maybe 2 years and then you started over again..

So we all kinda used a rather coarse river sand only and let the tank to it's own devices providing everything it needed by itself.. It took some time and eventualy it does, then it booms till it crashed into old tank sydrome..  And the cycle restarts, clean the tank and start over.. That was common practice.. Much later the importancy of water changes where acknowledged and resulted in much longer fun and have a health tank for numbers of years..

And now when you walk into the LFS there are 20 bags of different types of soil all driving you completely mad, all telling their own beautiful story. And in the end only overcomplicate things.

To be honnest, i do not read those commercial stories i only look at the easthetic value it has for me and the price.. It's always the price making me deside to look for alternatives in other places than LFS.. Then rather an inert alternative,so i can deside myself what more i put in and see how the plants grow and antisipate to that during the process of development..

And even in the todays high tech era, you can do as good on sand only as on any other available substrate..


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## sciencefiction

zozo said:


> Inert substarte wont be inert forever it's only an inert start..



I think in inert sand, low tech tank, my plants suffered for a year or two. Then they took off. The soil gives you an immediate effect and has much higher CEC


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## dw1305

Hi all, 





sciencefiction said:


> The soil gives you an immediate effect and has much higher CEC


I think those would definitely be the advantages of using soil. 

cheers Darrel


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## zozo

Yes that is true, that's why people using sand also add clay root tabs to rooting plants.. Then you create little pockets of high CEC clay into the sand bed.. Circle is round again... And there are so many different expriences going around that it is actualy a never ending discussion of yes versus no.. And all have a certain truth to the story but also is it a "what if" concept.. This because very aquarium is totaly different ecosystem..

Lately i ran into a discussion about deep sand bed substrates and the danger of anoxic/toxic anaerobe pockets.. Where one stated he had an aquarium for years with 20 cm of sand and never a problem.. While other aquariums he had with coarse gravel always developed gass pockets.. Explaination, gravel is more coarse debri sinks in much more easily and can develop a dense layer and anaerobe pockets, sand is less coarse so debri can't sink in so easily.. It's a valid point.. It's the same point why another one says that's the reason why i do not use porous lava based substrates, the debri sinks in creates anaerobe pockets and turns into a nitrogen bomb. Also a valid point, it can indeed happen..

The question remains, why does it happen and where are the mistakes made? It all depends how you set things up and maintain it afterwards.. For example do you have a lot of wood, what kind of wood, how old was it, what condition was it in when you did put it in the tank? Tanks with a lot of wood have much more debri (bioload) than tanks with only rock.... I see it in my current low tech, it has 5 kilo's of Mopani and the first 6 months it was a complete mess, never have seen so much debri accumulate on the substrate in such a short periode..

Look for example at a cup off tea which stands for an hour, it has brown tannin stains on it left by the tea.. Wood does the same in a tank, it not only stains the glass it also staines the substrate.. This are tiny particles, they accumulate and sink into the substrate over time and clog it.. Then you could say in certain scenarios, is it wise to put a lot of wood into a tank with a rather high elevated porous substrate? How is your flow? Where does it accumulate the most according to that..

Only time will tell.. Cause and effect..

These are all combinations of setups you could and should take into consideration, and think twice before one yells sand is better than gravel.. 

Not even to speak of, what lives in the substrate? How often is it turned over by the critters crawling around in it, some have them, some don't..
Do you have digging fish, they can completely distroy a sand bed substrate and make sink everything in.

So many things to take into consideration making comparisons even more difficult if not near impossible..


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## Soilwork

These are all good points.  I think one the best things about using a lava based gravel is that if you really wanted to you could gravel vac it from time to time whereas with sand or soil you can't (I'm trying to justify my purchase here to make me feel better) 

Does the same kind of thing happen in a filter.  The much that comes out when I clean is much like a soil.  Should we be leaving canister filter alone for longer periods before a clean or do they become inefficient and danger of low o2 levels.  


Plant aside, We should be able to rely on the bacteria/archeae in the filter for biofiltration?


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## dw1305

Hi all, 





zozo said:


> I see it in my current low tech, it has 5 kilo's of Mopani and the first 6 months it was a complete mess, never have seen so much debri accumulate on the substrate in such a short periode..
> 
> Look for example at a cup off tea which stands for an hour, it has brown tannin stains on it left by the tea.. Wood does the same in a tank, it not only stains the glass it also staines the substrate.. This are tiny particles, they accumulate and sink into the substrate over time and clog it.


 I think there are two different issues, the tannins and debris might clog the substrate and filters, but they actually add very little to the bioload. 

Most of a living tree is actually dead and comprised of a structural carbohydrate skeleton, the <"lignocellulosic">  material we call "wood". It has evolved to resist decomposition and is extremely low in nitrogen and sugars. The carbon will burn, but only a very <"specialised suite of micro-organisms"> can degrade it.  

There is a more complete explanation here: <"PlanetCatfish: Wood for tanks?">.  

cheers Darrel


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## zozo

dw1305 said:


> I think there are two different issues, the tannins and debris might clog the substrate and filters, but they actually add very little to the bioload.


That's why i did put bioload in brackets, i wasn't sure if bioload was the right word for, actualy also do not know if putting it in brackets means the same in english grammar, shouldn't have used the word at all in this case.. But as a very tiny dust like particle of biological origine it can indeed clog a substrate sooner then one might think.. And some wood can release quite a lot of it for a long time..  

Thanks for correcting and the links..


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## dw1305

Hi all, 





zozo said:


> But as a very tiny dust like particle of biological origine it can indeed clog a substrate sooner then one might think.. And some wood can release quite a lot of it for a long time.


That is sort of how a lot of the conversations on "PlanetCatfish" started. 

People kept _<"Panaque_"> and _<"Panaqolus">_ spp., (which are wood eating) and, <"then used the filter as syphon"> for the saw-dust and faeces with disastrous consequences. 

cheers Darrel


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## darthpaul

Had a walstad tank now for over 3 years without any filtration on it. I dont do water changes, I do top it up when it evaporates but that is dependent on the time of year. I only have snails and cherry shrimp but they seem happy enough. My thread is here although the tank is a lot more overgrown than the last picture I added! http://www.ukaps.org/forum/threads/mini-s-walstad.28426/


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## PARAGUAY

A good look in for low tech is"Natural Aquarium" which the founder mentions no mechanical filtration,basic t8 lights,but plenty of water changes .As often said by Darrel the plants are the filters


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## dan4x4

just for info, I have John innes number 3 substrate. I reduced the flow as some of the old leaves on the plants had started dying. I assumed that this was a lack of co2 - as reading "Ecology of the planted aquarium" co2 is always the limiting factor. No improvement was observed over approx 2 weeks. I then reduced it further and I'm now observing an increase in algae. 

People on here recommended me not to reduce flow haha I should of listened. Anyways, I also put leaves in. Beech leaves, Oak Leaves & Alder cones. No changes based on the leaves. But the cones made the water shaded, day by day. However after 2 weeks and no water changes, the tannins where gone and its crystal clear again. 

I pruned back heavy also at the time of reducing flow.

Im just going to see what happens now I've increased flow. Plants arent dying anymore, Im assuming the alder cones provided a boost in co2 with the humid substances.


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