[Gennariello]

Santamonica, I am writing in English for you.
I am planning to build a filter using one of the two overflow connecting the tank to the sump. I will have quite a big waterflow, the tow of them support more than 1200lt/h.
I will use a very simple design. I will use an horizontal pipe with the cut in the middle end the net located in the cut as usually. As my sump has a very high side glasses, I will use that to protect the lights. Out of the sump I will locate some impermeable strips (it is not really needed, but safety first). I will use red led-stripes.
With this design I can have light only on one side of the net, I know is not the best... :(
How large should the net be?
How many Watts?

My tank is about 300l and has many problems of phosfate and nitrate. I think I am not overfeeding but maybe I do!