Home made overflow box

NanoTy · Sep 13, 2015

Has anyone ever tried to make there own overflow with a hob filter? And if so did it actualy work or were there issues?
Ik hob filters have an impeller motor to pull the water over the side and the feed tube in the tank sits well below the water line but a simple hole to help break the siphon would be as simple as drilling one and if the motor dies or burns up most hob filters are cheap and the motors/pumps are removable so replacement could be fast instead of having to rebuild a new.
Pros/cons, if you have tried it or not, or even if the idea just interests you please voice your opinion I will be starting the project in the next few days to see how well it will work for myself.

Harold Green · Sep 13, 2015

I bought four specimen containers and cut drain teeth in two of them. Bottom drilled the other two and placed a one inch pvc fitting into them to drain down under the tank. Bought two clear one inch siphon tubes to go from inside container to outside container. Drilled a hole in the top of each siphon tube for a one way valve with airline tubing draining into the drop down one inch pvc to automatically remove air bubbles. Ran well for years into a wet/dry I was using at the time.

NanoTy · Sep 13, 2015

That seems like alot more work to set up than what I have in mind.

Harold Green · Sep 13, 2015

Much easier to use a reef ready tank or drill your own. Since you would normally have a pump in the sump returning water there wouldn't be any way to actually match that pump to a hob filter that's pumping water out of the tank. If either one got ahead of the other you'd end up with water everywhere and burn out pumps to boot. The only way I could see to make that work would be to use a filter that's submersible and put it into the tank with a float switch controlling that pump and it would have to pump more than the return pump so it could keep up.

NanoTy · Sep 13, 2015

The hob wouldnt actualy be pumping water to the sump, only out of the tank and then a bulkhead would be on the back of the hob as the overflow to the sump and any extra flow would return to the main tank.

NanoTy · Sep 13, 2015

But like you said a pre drilled tank would be easier...but im not looking to go that route. And also the pump on the hob wouldnt run dry if the bulkhead is on the back of the hob in the middle or at least above the pump and lower than the water line.

Fin · Sep 13, 2015

I don't think that will work. I believe you are thinking that it will work like an overflow, but if your sump pump overwhelms your HOB filter pump, the water won't just run out the back of the HOB filter through the bulkhead, it will run over the top of your tank and onto the floor. If the HOB pump fails or stops up, you are in trouble. The amount of flow out of the HOB filter is dependent on what it can pump out of the tank. I vote drill your tank. You will be a lot happier in the long run.

Harold Green · Sep 13, 2015

If you don't want to drill the tank then the second option is to just purchase a good factory hob overflow. As long as you size it properly for the return pump and then keep the air out of it, it can work almost as well as a drilled overflow.