The tanks are stacked...sort of like a reef tank with a sump...same theory anyway. The top tank is drilled in the bottom glass and has a PVC
"overflow" that drains into the bottom tank. The bottom tank has a DSB
, a Lee CC skimmer and a MaxiJet 1000 PH that is used to return water to the top tank. No other filtration. There is a blue damsel in the bottom tank and 2 green chromis and a sailfin blenny in the top. There is an assorted collection of crabs and snails in both tanks. I feed these tanks like crazy...all the fish can eat and lots of chromaplex and phytoplex. I also had some CSL coral food, but I'm out of that now. I throw in some frozen "invert food" once in a while too. Nitrates have never been readable. I haven't done a water change yet
...just topped off with fresh water every day.