Mike is correct. If you can get 30LBs of LR
in there, you won't need a filter. The LR
/sand will give you the biological filtration you need, along with a PH or possibly two.
The sand, I dont know anything about FW
. Is it silica based sand or aragonite? I would imagine you could use the sand in your FW
tank, but I would get some more opinions, first. Aragonite is preferred, since it opens up options for clean up crew and sand sifting critters/fish.
Mike is also correct about the copper treatment. If it have been used in that tank, you will have possible problems keeping inverts alive in the tank.
Here are some fish that are considered nano fish, or at least better suited to smaller tanks:
a small cheap skimmer (recomendation please!),
If you are going for a FOWLR
, you could probably skip the skimmer, for now, especially if money is a concern. This is one of the pieces of equipment, I have read you should not skimp on. With proper PWCs, and good filtration, you should be good without one. That is just my opinion. I have a 55G and don't use a skimmer. There are plenty of others that love them.