Well I changed my mind - I like saltwater too much - I wondered about any contaminants from previous critter or treatment in this used tank, it seems to be OK. I want to raise sea horses, the tank is 36L x 18W x 24H - I think it will be perfect for horses. I hope some of the horse keepers chime in, the only thing that is changing with the sum is where the basket of bio balls or red brick I will put a skimmer - I can add a fuge with a separate tank, have a few kicking around - 20 gallon in mind already drilled. I am excited to read more about them, I have read the stickies on this forum. Hopefully something can be put together that works for me. I would really appreciate some guidance. Thanks for now.