thanks guys,
I appreciate your comments very much.
gregkn73, i have seen Dymico system, it seems a filter in which nitrification take place in the upper, more oxygenated part, and denitrification take place in the bottom, where the oxygen lacks.
I don't see differences (biologically speaking) with a DSB.
Yes, my temperature is actually 31°C (or 88°F)...I have a single pump with an asynchronous three-phase motor that generates a large amount of heat, more than I expected, and is only 350 W.
Room temperature is about 26°C...probably I will need a chiller.
All the techical tools are located and hyded under the tank.
In spite of the temperature, my fishes are comfortable and thanks to the oxygen cylinder, in the water I can mantain 8.2 mg/l O.
Luca