Originally Posted by jzon414
i dont think it can be tempered at this point cuz it has a chip in it already and survived so.... and the return would be at the same level as the drain, the first picture just doesnt show that, but either way should have a check valve in it anyways though.
and what do you mean cuz its a horizontal overvlow? what would make it a vertical one? cuz its only horizontal at the point where it comes out of the tank which i would think would be the case with any overflow
EDIT** unless yout talking about a hole drilled in the bottom of tank right? if thats the case would it be better to build a corner overflow box and have the bottom drilled for thte drain?
Yes bottom drilled means vertical, which has faster flow rate; this is not important if you plan for it, I like horizontal overflows and make them on all my tanks, they are quieter and safer. If my overflow fails I lose 5 inches of water out of 25 at the most. If a bottom overflow fails you loose 25 inches of water. The reason vertical is faster is the flow is aided by gravity, the whole time. Where as a horizontal its only aided by gravity after it leaves the tank, it still has to flow sideways to exit the tank.
If the return and drain are the same height a check valve on the return only adds restriction and no safety.
Another nice part about horizontal is if you design it right you can change it to be a drain for water changes. For example when I want to change the water I used to just turn the 90 degree elbow so instead of facing up at the top of the tank it faced the bottom, I then added the proper length of pipe. this would drain the tank to that level very easy.
Since then I have drilled a dedicated water drain just for water changes, and placed a ball valve on it, now my water change is consist of truning two ball valves. I turn the first one go get a snack come back and the tank is drained to the proper level, I close that valve and open the one that adds new water to the from the houses water main.