Plants in the sump: extra bio-filtration?

[Mount_Prion]

So in breaking down my 30g planted into a grow-out, I realized I'll have an extra very powerful plant light sitting around.

I had the idea to lie it on the ground angled facing the bottom, empty part of my sump, right under the bioballs, and to fill that empty space with plants for extra biological and mechanical filtration. You can't have too much filtration, and obviously the idea of a lush, living layer of filtration in my sump is appealing.

So far moss balls (lots of them, big ones) seem like the best choice to fill up the space with. They seem like they'll thrive having detritus drizzled on them from above (and just grow bigger around it) unlike some plants that would get dirty leaves and die, and the moss balls seem like they don't need a ton of C02/fertilization to survive. Being marimo, they will obviously have great surface area for physical filtration.

In the below artist's rendition of my ~30g sump, the light blue line is my standard filter pad, the blue Stars of David (mazel tov!) are my bioballs, the pink bar with the yellow lines is the light, and the brown arrows represent the pumps. The red square is a CO2 diffuser (put under the sponge from the pump that pushes out to where most of the plants in the tank are) and the gray bar with yellow stripes is my wall of filtration, made up of bags of ceramic bio rings, phosphate reducing stuff, and eheim torf pellets. This wall of filtration is meant to put the water chemistry where I want it whilst physically stopping detritus from reaching the filter sponges.

So ultimately, does this setup make sense? Do moss-balls seem like a good idea or should I put some other kind of plant? I was thinking of throwing a little java fern in there for good measure.

And should I try putting anything that moves down there? Like maybe some albino bristlenose plecos or some kinda shrimp?

Thanks!

 

[wrslrcichlid]

I could be wrong on this (maybe got bad info), but I'm pretty sure you are supposed to squeeze marimo balls every once in a while because they catch waste and then it kind of sits in the middle of the ball (if I remember correctly they are hollow). I believe this is what the moss feeds on, but at the same time they can get pretty full. Just something to maybe look into and think about with having them in the bottom of the sump.

Otherwise I think it is a great idea and say go for it.

 

[mitchb]

Those are very nice stars of david, which is what I thought they looked at when I opened the thread. The only thing that I could see causing an issue is that Marimo balls are supposed to be very slow growing, which would imply that they do not use a lot of energy which could mean that they don't eat up a lot of nitrates? I guess with a lot of them you could eat up nitrates, but if you had too many the light would not be able to get through to get to the ones higher up or behind the initial row.

When people talk about plant bio filtration pothos seem to be a great choice, and they grow very fast which is where I am getting my reasoning from regarding the DE-nitrification being based on growth of plant size...

Personally I would just have some pothos coming out of the side of the tank with their roots in the water that settles from your drip tray. If you are going to put a light down there I would want to get the biggest advantage out of it and get the most nitrate reduction possible.

You could also look at a turf scrubber if you just want the nitrates out and want to go with algae/moss or whatever grows on it?