freshwater tank, green water

[Hermie]

Hi all, figured I'd ask on here being my most trusted aquarist website...

I have a 20H tank with partial dirted substrate (about 1/3) capped by seachem flourite.

The tank's water is totally green as of the past few weeks. I've never really experienced this in freshwater, however what would you recommend?

• I think the dirted nutrients are leeching out into the water column because the flourite is such "large grain" so I may need to cap the flourite with sand. What do you think?
• The tank's only filtration and circulation is an air powered sponge filter, but I am not sure if increasing biological filtration would prevent green water. Should I increase circulation to help the plants grow better?
• I am trying to keep the tank as low tech as possible, and mainly I have it to grow snails. I don't like impellars in this setup because snails will get stuck and ruin them...

The tank currently has a ton of christmas moss (dubyana), a few Jungle Val plants, 2 cypress helferi, 1 struggling onion plant and numerous java fern "plantlings"

 

[Bryson.bobby]

Maybe try a UV sterilizer

 

[Hermie]

Maybe try a UV sterilizer

yea I just took my UV off my reef tank and put it in the 20H but I'm worried it won't be a long term solution

 

[Waters]

I would pick up a cheap green machine UV and just leave it running on the tank. The green water could be caused by a lot of things....excessive nutrients, lighting, etc.

 

[riche]

Are you in direct sunlight? The only reason you get green water is from too much light.

Water changes and less light will help long term. A uv light helps but its a band-aid to the issue

Another thing that will contribute to green water is lack of water movement, so adding a air stone helps a ton.

I'm more of a freshwater guy so I know more about freshwater then I do saltwater :)

 

[riche]

And after reading more of your post you are for sure doing it right. A sand cap will work and help keep the substrate from getting kicked up.

Since you have a sponge filter ( All I will use in my fish room breeding tanks), light is what is causing your green water.