I have a Wet/Dry sump filter in a non-drilled tank.
There is an assembly called the "overflow" which prevents overflowing to happen.
In truth, in order to prevent overflow a few things are needed, none of them hard to do:
1) The output hose, from the water pump or
powerhead in the sump to return water to the tank, if submerged below the tank's water level will reverse the flow -from the tank to the sump- every time power is off in the water pump or power head. To prevent this you need to make sure that unwanted siphoning back is interrupted by: a) keeping this output hose above tank's water level at all times; b) keeping it slightly submerged, making sure it will siphon back some water but will stop siphoning before your sump gets flooded, c) drill a tiny hole in that hose, above water level, that will suck air in when reverse siphoning occurs and that air build up will brake the siphon (this needs an inverted U or inverted U like shape form in the output hose).
2) The overflow device keeps the input siphon in place, at stall or stand still, when the water no longer enters in it. When power is restored, it will continue flowing. The best way is either to purchase one of this assemblies or carefully build a
DIY model.
3) The sump water level must stay somewhere in the midline so you have enough room to accept incoming water without flooding the whole place. Keep in mind that when you do maintenance you need some flexibility here.
Side notes: The overflow assembly consist of two boxes, one goes inside the tank, the other one outside. Both boxes are connected by an inverted U shaped rigid tube, which will have a small airline hose inside it. The U shape tube needs to have one side longer than the other; usually one inch difference is used. The shorter side goes in the inside the tank box; the longer one in the outside box. The inside the tank box usually have many vertical indentations, that will allow water to flow in to a certain level. The outside the tank box usually have a cylindrical hollow sponge around the hose that takes water from this box into the Wet/Dry sump input.
Once you check your system is over-flow risk free, take it easy, you have one of the best available filtration systems in place!
Pepe
Santo Domingo
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