I don't want to throw you off track here, but I may have a solution for your water area. I've built most of my own filters for my ponds from your basic pond pump and various other materials. I'm currently building a 20gal PCF tank with about 2in of room for water. The filtration I'm using is the same idea a my pond just scaled way down. There are small shallow pumps out there. If you PM me your email or phone #, I can email/text you what I'm doing for my build. I also cannot post pics with my phone, but would happy to send them directly to you.