Hola, me hacia falta traducir un texto, pero los traductores que hay por internet no me lo dejan muy claro ya que no entiendo practicamente la traduccion.

Si hay alguien tan amable de echarme una mano, se lo agradecería mucho.

The tanks overflow (come back on that later 1) the water goes trough the pipes and comes in the spray bars, I made those spray bars to get the water as much as possible over the surface of the foam. The water goes trough the top layer of the foam. The top layer of the foam (1 of the 3) is above water this is kind of my "dry filter". The other 2 layers of foam are under water (my wet filter).

The filter foam is laying on the creates, in a few filter systems I used 4" pipes with holes that they use for drainage to put the foam on. Because I ran out of free creates lol.
I put the foam on the creates and pipes to get a space under the foam (come back to that too 2).
So the water goes trough the top layer of foam and trough the 2 layers of foam under water.
At the bottom of the filter is a pipe that brings the water to the pump under the rack, the pump pumps the water to the tanks and (1) the tanks overflow.

Okay the space under the foam I made with the creates and pipes I did for a reason (as everything I do lol) (2)
The pump, that brings the water back to the tanks, is on one side of the filter system at the other short side of the filter system is the refill point for the filter system. If I do a water change I just change 2 valves, I close the valve to the tanks and open the one to the drain, so the pump that normal brings the water to the tanks, pumps it now to the drain.
Most of the dirt in the filter ends up in the open space under the foam. Most of the dirt goes with the water, trough the pump into the drain.
Now there is always some dirt left, before we refill the filter system again, we "flush" the system a few times, that means we open the REFILL for 10 seconds at the other side of the filter and the water flows trough the open space from the refill side to the pump side of the filter system, taking all the dirt with it. If this is done, we refill the filter again, switch the valves again and did the water change.