Nitrate will not go down...

[Carandiru]

Yeah the porcupine puffer will only be moved if he gets too big. The snowflake eel however is planned to be moved to a tank downstairs already before he gets aggressive and eats other fish.

I do like DIY but I'm now wondering about a denitrator coil, I might aswell build one of these along with the pvc skimmer. Do they work? The sound so simple to build just wondering if anyone has built one.