# Water movement in a Walstad tank



## Karl M

In a traditional tank I was always told that your filter should circulate a minimum of 3 to 5 times your tank volume per hour. In a Walstad tank where the plants are doing all or at least most of the cleaning how much water should a powerhead move to provide ideal circulation?


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## kerrigan007

In my 3 Walstad tanks, I have a filter which is more intended for water movement than filtration (only 1 media in each filter, not more). One of these filter is not meant for a 10 gal but for a 5 gal and I have absolutely no problems with that tank (as in the others). 

Since it is very well planted, I feel that there is not need for better water movement. 
In fact, Diana Walstad even suggests that you use no filter at all, but you may use a powerhead to create some water movement and help with oxygenation. So in my opinion, you can go with a low circulation filter. I would not bother about this. 

But let's wait for other answers, since I'm new to Walstad method (since february).


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## Karl M

Thanks kerrigan or your response.

Maybe I should give a little more info. I have had many aquariums and raised many fish over the years but have not had one set up in about 13-14 years. I have tried to raise plants and have the "balanced" aquarium but have always failed. A few plants survived but none thrived. Recently I have been thinking about setting up an aquarium again and began doing some research to see what had changed in the hobby. That is when I came across Diana Walstad's book which I purchased and read. I have read many articles and watched many videos and think I am about ready to take the plunge. I have a 55 gallon aquarium that has been used as a terrarium that I plan on setting up "El Natural". I plan on having a well planted tank with a low to moderate fish load. I originally had my eye on an over the back filter that was in the 250+ gph range but have since realized that I didn't really need that. So for a 55 gallon aquarium does an 70 gph flow create enough circulation, or is 120 better, or 150. I know that there is probably a range of answers depending on the types of plants and fish but I am curious what more experienced aquarists think.


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## SBS

I setup two Walstad tanks this year and both have very good filtration and flow to about 10x the water volume an hour. From one point of view it's better to have filtration as a backup in case something happens with the plants, they start melting, not growing fast enough to support the bioload or just for insurance to have a more stable tank and give you room for extra bioload.
And from another point of view good flow transports all nutritients and co2 equally to the plants around the tank. It also gives you mechanical filtration to keep the water clear. I also found them beneficial this summer with my tanks hitting over 30C(86F) temperatures. 
And of course, the fish you intend to keep may like a degree of flow too.

Here are a couple of pics of my tanks I've setup NPT with lots of filtration. If anything,I can only see benefits of having good flow and filtration in such tanks. I think even Diana said it recently that it's better. The water is yellow not because of the soil, but because I've put alder cones and oak leaves in the tanks.

Tank is a bit overgrown as I've had no time, so sorry for the jungle mess. This is my 100G with 3 external filters giving about 1000G/H flow overall.









This is my 7G with a 120G/H filter


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## Michael

I agree with SBS on this. There is a good thread here on how to set up circulation http://www.aquaticplantcentral.com/forumapc/filtration/88242-how-setup-proper-water-flow.html


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## jojo jose

Karl M said:


> In a traditional tank I was always told that your filter should circulate a minimum of 3 to 5 times your tank volume per hour. In a Walstad tank where the plants are doing all or at least most of the cleaning how much water should a powerhead move to provide ideal circulation?


Hi Karl M!

A few days ago I posted that exact inquiry here in my thread and had exactly the same thoughts on water circulation that you had. We also had the same assumption on the Walstad concept and just wanted more specifics on water movement... I guess after some reading on the issue and after seeing many setups here at APC, there is not really a definitive answer like math. Any possible combinations/methods you would like to apply can and may work in a Walstad tank. On the other hand, those same combinations may also not work at all given your specific situation. What is important though is keep a watchful eye on what we are doing and tweak things as we deem appropriate as we move forward, just keeping the basic guidelines in mind.

My take on water circulation is more on (some) movement only since I only have a tall 20gal tank, minimal filtration just to polish the water column, light bio-load on a new setup in order to keep things stable during the "formative" days. Movement becomes more important with the longer tanks as I recall at 24inches++ length. HTH


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## Karl M

Thanks everyone for your thoughts! I appreciate your wisdom and your willingness to share it. It will be a couple of months probably before I get the aquarium going. I am looking forward to getting back into the hobby.


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## apctjp

In a low tech, planted tank environment, old plants will die and new growth will take place. As organic material breaks down and decays, the process depletes oxygen, that is surrounding the material, and eventually creates methane gas. The power head should create just enough circulation to replace these pockets, of depleted oxygen, with new water.


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