When you chose your return pump make sure it has enouth capacity to keep the overflow box flowing strongl. I had a Rio 1200 and the u tube kept developing an air bubble which would start to restrict the flow. Following advice from this forum, I upgraded to a Mag 5 and that solved the problem. And that is for an overflow box with a 3/4 " u tube. One with a bigger diameter must need more flow.
about overflow boxes
- Thread starter tangov559
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fullkontact
New member
Aren't there only 2 dangers with spillage? 1, if you lose siphon, and the return pump tries to empty the sump into the tank. (if you plumb the return pick up so it always takes the top couple inches of water in the sump, shouldn't that take care of it?)
and 2, if your return pump loses power, (just have enough room in the sump to cover for that low amount of tank water.)
I don't really know what I am talking about, I just read that somewhere and it made sense. Am I wrong?
and 2, if your return pump loses power, (just have enough room in the sump to cover for that low amount of tank water.)
I don't really know what I am talking about, I just read that somewhere and it made sense. Am I wrong?
Avi
Premium Member
That's just about right....but losing the flow through the U-tube is a very unlikely event. Most likely, this would only happen if an errant Turbo Snail got into the internal part of the overflow and blocked the flow through the U-tube. So it's a good idea to put some kind of cover on the top of the part of the overflow that's in the tank. That would make a problem of that kind even more unlikely. Still, if you ever do lose the "siphon," then the water wouldn't be making it's way down to the sump and once the water level in the sump goes down to the sump-return pump, the flow would stop. Depending on the water level in the sump, that's how much would be sent back to the tank without water being drained down. The flooding that would result would be the amount of water that would be pumped to the fishtank after your tank fills up to the brim and starts to overflow its sides and the sump-return pump running dry. But remember, this is like a worst case scenario because, again, the failure of an overflow with a U-tube is inlikely. By the way, you can ensure that this is never a problem by having two overflows if the tank's size would make it possible.