I am running 2 externals on this tank, but the issue with my Discus is that they really don't like much flow in the water. They can handle a little bit, but if the flow gets too much then they will try and find a dead spot in the tank and all huddle there. With near zero flow they casually swim around looking happy. To get around this I previously had complete UG plates under the bed, and plumbed the filter return lines into what were normally the uplift tubes. With this I could run both filters wide open and the water would be seeping up through the gravel across the entire floor of the tank, and thus creating no flow. I had also plumped the Co2 in to the tubes so that the plants were getting a nice even amount of Co2. It worked really well, and also help keep light sediment in suspension and the gravel clean. Anyway I can't do this with the sand, so I will have the UG feed plates under the gravel at the hardscape end so that one filter can run full throttle, with the second filter returning water to the top of the tank, but at a low flow. I will revert to a regular ceramic diffuser for the Co2, and locate it at the planted end.
Here's the plates and uplift to be feed by one filter.....
......
Now a thin layer of gravel to cover the plate at that end......
very beautiful
and your welcome
Love your discus fish so much
