Last weekend we worked on the overflow system, where the water in the fish tank overflows into the sump tanks. I bought a 3 inch diameter bulkhead fitting (the grey thing sitting on top of the cinder block) for each of the two fish tanks. The above photo is Burr cutting the hole in the side of the fish tank where the fitting is installed. The tank material won't bond with any sealants for very well so we knew we only had one chance to get the hole right.
This is what the bulkhead fitting will look like when it is set up in the tank. The top part is inside the tank and the bottom part is outside the tank.
The white PVC pipe flows from the fish tank at the top of the photo...
...to the sump tanks. These two tanks are connected underground, so that when water is added to one, the level will equalize between the two. The pipe with the red valve in between the the tanks is a water supply line that will eventually be hooked up with a float valve to add water to the system if the water level is low. I am on well water, so I don't have to worry about chlorine in the water.
