DIY bio filter material

[Sarkazmo]

So I've got plans to make a DIY sump and need suggestions on what to use for biological filtration media. I know what the stores sell for this but what I'm looking for is something that can be used for it but not intended to be used for it.

So far I've come up with:
Lava Rock
Tons of bath scrubbies (nylon webbing)

What do you suggest?

Sark

[Cliff]

If I remember correctly, Aeonflame did a post about a DIY filter he made for a pond using a 5 gallon bucket and DYI filter media.

I can't find this thread for the life of me tonight.

Hopefully he will see this post and offer advice,

[Sarkazmo]

You mean this thread?

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Sark

[MCHRKiller]

You could also look into some CPR skimmer "bio bale" you get a ton of it for the price.

[tanks4thememories]

Im really impressed with the statistics ive been reading on matrix by seachem. wow Im doing research on nitrafying bacteria and Im impressed.

[Cliff]

You mean this thread?

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Sark

Yup, thats the one, hidden right in plain site

If it was a snake it would have bit me (blush)

[BIO-Linist]

How big are "scrubbies" and how much do they cost?
It may actually be cheaper to use intended filter media, perhaps in unconventional ways...

On my pond I have planted, floating platforms made from big Marineland filter pads with pieces of disposable foam lunch plates stuffed inside for flotation. Each 1 inch thick, 1ft x 2ft pad cost near $6 at pet store. You may be able to get a better deal as I've seen them advertised down to about $3.something on the internet. In addition to the great surface area of the pad itself, the plant roots provide lots of surface area for nitrifying bacteria. Depending on your energy costs, you could possibly do the same in the sump with grow lights.

The plant I used is Bacopa. A local version called 'ae'ae is commonly used as a groundcover plant. It grows much better with the stems and leaves out of the water.

One major problem with this system is insect infestation. Aphids and other pests came and destroyed most of the plants every once in a while and the water turned brown like tea. This is much less likely to happen in an indoor setup. The picture at the top shows the plants recovering after a major attack. The second picture is an older picture when the plants were really growing good.

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Another option is to use floating plants like duckweed, but I think they're too messy and hard to control. And I also really dislike them for environmental reason as they tend to be highly invasive - a while back there was this huge infestation of salvinia in a lake.

I have also read about setting up a system consisting of plastic screen with water flowing over it and lights, to grow algae to eat up nitrate and phosphate. It's promoted as a "mega powerful nitrate and phosphate remover" (search that phrase). And there's this guy(?) who posts at many different sites hawking it like a salesman (mostly encourages people to diy it but (s?)he does sell).

Will you answer my questions in your previous sump designing thread?
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