Wierd stuff at the bottom of tank?

[Jason the Lost]

I vacumm this stuff up and a week or so later I start seeing patches of it again. It looks like little strands of somthing...at first I thought it was just decomposing plant as the plants were getting in bad shape, but thats under control and everything is pretty green...no idea. Its not attached to anything.

 

[rich311k]

Looks like normal mulm to me. Fish waste excess food etc.

 

[tropicfishman]

yep same ehere

 

[Devilishturtles]

Same here. Its ugly, but there isn't much to do about it. Fluff reccomended to me to get more plants so you can't see it.