All plant filtration? - El Natural

jsuereth · 03-16-2012, 08:10 PM

Hey guys!

I'm setting up my 125G for "El Natural" growth. I have two questions, but the first is what's bugging me. Is it possible to have an *all plant* biofilter?

I read blogs like this one and it makes me want to tinker with things.

Well, I have an empty 125G waiting on money to finish its sump. BUT, what if I el-natural it and go filterless? How many fish could I support in the tank? Ideally, I want otos, corydoras + tiger barbs (my daughter's in love with them), but I have no clue what kind of biomass emergent plants can maintain.

I ordered some Cyperus Umbrella sedge, a similar plant to what's used in the above. I also have a *ton* of plant for inside the aquarium.

My plant list so far:
* Cyperus Umbrella sedge (main source of filtration, grows 2-6 ft tall)
* "Centerpiece Cluster" E. Ozelot (Red), Rotala, C. Wendtii (Red)
* "Invert hiding" L. Mauritona + E. Tennellus (Or whatever it's called now)
* Some type of Amazon Sword (large leaf).
* E. Augostifolia "Vesuvius"

I've tested all the plants (except the cyperus) in the same aquarium for allelopathic issues. Things *appear* ok.

Do you think these plants will provide enough filtration? Should I pick up more 'aerial' plants? Anyone grow Water Hycianth before?

Thanks for any help. I figure, this is the best forum, of any, to ask

Michael · 03-17-2012, 06:23 AM

Yes, you can set up a tank using only plants to filter the water. You will need to provide circulation with powerheads. Aim for total water movement of about 10x the tank volume per hour. Arrange the powerheads to create a smooth circular flow in the tank. The circulation is important so that nutrients and oxygen are distributed evenly throughout the tank. You are relying on the biofilm that forms on every surface in the tank for most of your filtration, so you want water flowing around all of those surfaces.

The cyperus will become enormous--mature plants can easily be 5 feet tall. I don't think it is practical long term in a home aquarium.

Keep your fish population low until the plants are well established and growing, then you can stock normally.

jsuereth · 03-17-2012, 06:38 AM

10x my water size per hour, so... 1000 GPH? If I set up two 500 GPH pumps on either side, will that provide enough flow across the tank? I.e. is this more about flux (as I suspect) or raw flow?

As for the cyperus growing 5 ft tall, I'm ready for it. I picked up "dwarf" cyperus, which claims to only get to 2', but I'd prefer a good 3-4' before I trim. In the room I have this set-up I think it'll actually look pretty good.

As far as stocking, I'm trying to dry-start the plants now, so I hope to have them very well established before adding fish.

It's good to know the idea is not insane. I can't wait to see how much filtration pure plants can handle.

Any other suggestions for high-filtration plants? i.e. if you didn't use cyperus, what would you use?

Fabien01 · 03-17-2012, 12:09 PM

I think all emergant plant ( aerial advantage ) would be good !

i have had a cyperus in my open tank, it was Cyperus alternifolius ; approx 1m20.

there is a pic on my NPT blog : http://aquanp.blogspot.fr/ to give you an idea.

And Cyperus has very strong roots !

Michael · 03-17-2012, 04:43 PM

Quote:

Originally Posted by jsuereth

10x my water size per hour, so... 1000 GPH? If I set up two 500 GPH pumps on either side, will that provide enough flow across the tank? I.e. is this more about flux (as I suspect) or raw flow??

Exactly. Put the pumps in diagonal corners, with one pointed along the front glass, and one along the back. In most set ups with short plants in front, the pump in the front corner can be deeper, or directed slighly downward. The one in the back usually must be mounted high because the tall plants block the flow. If your soft-leaved plants are swaying gently in the current you have it right.

I'm glad you know about the cyperus, most people are not prepared for it's size when mature. And it will be interesting to find out how large the dwarf variety actually gets.

Douglas Ingram · 03-23-2012, 10:27 AM

I have a 30 and 40 gal running with no pumps at all and they're doing ok. They'd probably do better with some movement, but I'm seeing what they'll do this way for now. Its been about 1 year so far.

My 90, which can be seen in the NPT photo thread has only a simple HOB filter running to help clear out floating debris. Other than that, the plants are doing all of the work.

Experiment with the pumps, you'll see what flow works best for you. There is no single, simple, answer.