# Drilled overflow - box or screened outlets?



## Richard M (Apr 16, 2016)

I'm about to build a sump for my new 6 x 2 x 2 tank; I'm going to use drilled overflows from the main tank to a 4 foot sump below.

I've been looking at a Herbie-type overflow box but the only professionally made ones I can find are in the USA, they're expensive for what they are and the postage is horrendous - I don't really want to spend $AU200+ (more than I paid for the 4ft sump tank) on something so simple - it really grates with me.

The other possibility, which I've seen in local pet/fish shops is a simple screened inlet screwed into the drilled outlet hole with a bulkhead.
Any pros/cons to doing this?

I was thinking 2 x 40mm (1.5") outlets set horizontally, with a third open outlet set vertically, a little higher than the others to act as an emergency overflow.


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## CeeJay (Aug 16, 2016)

I think the only thing you might get is just a little more noise. If I had the choice I would drill the back and not the bottom. Just a safety thing. If you would get a leak in a bulk head the whole tank could leak out. I have seen a lot of articles Herbie-type over flow on the net it doesn't sound that hard to build yourself. If noise is and issue I would think this something you could over come in others ways. Even store bought overflows can be quieted down with more then one returns or using a manifold. They also make what they call a muffler to put on your down flow pipes.

Hope this helps.


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## Narwhal72 (Sep 26, 2006)

A simple screened overflow can cause problems.

1. it doesn't do a very good job of surface skimming. You need a wier (an internal wall) for the surface water to go up and over for it to surface skim properly.
2. If it gets clogged your aquarium overflows. The strainer can clog up with all kinds of debris and when it does the water level in the tank rises. Depending on how close your water level is to the top of the tank you could overflow your tank before the sump empties. Your emergency drain will probably prevent that. But why add that if there is a better way to do it to begin with?

Putting in a weir will conceal the bulkheads and piping, gives you good surface skimming, and helps prevent overflows. You can build one out of a simple piece of cut acrylic. Inside the weir, you can do a variety of different plumbing methods to make it run quieter.

Andy


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## LXXero (May 4, 2016)

you can just buy some glass pieces and silicon them in place to build your own if your comfortable with that, probably cheaper than shipping stuff overseas.


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