can a hang on overflow box?

[ryangina]

can a hang on over flow box flood a sump if the pump fails to return water to the tank like with a power outage?and whats the difference between a the hang on deal an having a tank with an overflow built in? thanks ryan

[bobby]

it will if you dont have it set up right i dont know if all o/f have nuts to adust the hight but some do and you can adjust it so the rim were the water flows will have room to keep sucking down water but not too much room were it sucks too much down if the power goes out and over flows it and a built in o/f will alway have continus flow with uot overflowing if the power goes out becuse it will run dry and doesnt have the hump over the tank to fill back when it goes dry now there are weir o/f with a pump for continus flow for the time the power does go out so when it dose go dry from the power outage and the pumps turn back on the pump will fill the o/f again i have heard some bad thing about the weir type but dont know much about them my self may sombody else can answer that one for good luck

[ryangina]

so a built in over flow is the way to go?from what i understand of them the return pump from the sump makes it work but shouldnt flood the tank as long as the pumps gph is lower than the o/f? ive ive got a couple extra tanks and would like to make a sump and o/f im just trying to get some better knowledge on how the system works and all.

[Bifferwine]

I have an overflow box. It will overflow the sump if you don't set it up right, so after you set it up it's a good idea to do some "practice power outages" and turn everything off to make sure things would be okay in a real-life power outage.

The idea of the overflow box, is that it will only send the amount of water to the sump that is above the lip of the overflow box. Any water below it can't overflow the lip and be syphoned out. You need to have enough empty space (i.e. not filled with water) in your sump so that if the return pump turns off, the overflow box can drain all of the water above it without flooding the sump. So if you put the overflow box too deep in your tank, the sump will not be able to hold all the water above it and will flood. If you put it at the very top of your water column, the unfilled portion of the sump will be able to hold any water above that level. I hope this helps and wasn't too confusing...

[ryangina]

thank you that does make alot of sense.so what i have is a 55 gallon walmart tank that is sw it has live rock and live sand only two big peices of rock but i have a blue spot ray and she has to have a bit of room to bury im also running a fluval fx5 and a seaclone 150.so what i wanna do is switch to a sump so i can have only sand in the tank for the ray even though she doesnt bury much.

[Bifferwine]

I have a 55 gallon Walmart tank too. The overflow box I have works fine with it. You will be fine as long as you don't put it too far below the water level. The problem with mine is that I also have a Walmart stand, which is too small to fit any sump underneath it (not even a 10-gallon tank fit), so I had to put a 20-gallon sump on the floor next to the tank. Hopefully you have a better stand than I do!

[ryangina]

Originally Posted by Bifferwine

I have an overflow box. It will overflow the sump if you don't set it up right, so after you set it up it's a good idea to do some "practice power outages" and turn everything off to make sure things would be okay in a real-life power outage.

The idea of the overflow box, is that it will only send the amount of water to the sump that is above the lip of the overflow box. Any water below it can't overflow the lip and be syphoned out. You need to have enough empty space (i.e. not filled with water) in your sump so that if the return pump turns off, the overflow box can drain all of the water above it without flooding the sump. So if you put the overflow box too deep in your tank, the sump will not be able to hold all the water above it and will flood. If you put it at the very top of your water column, the unfilled portion of the sump will be able to hold any water above that level. I hope this helps and wasn't too confusing...

ok so with that these o/f boxes are makeing more sence so now if it doesnt overflow the sump when the power goes out will it overflow the tank,does the sifon stop?

[Bifferwine]

When the power goes out, the return pump will stop, so it will not overflow the tank. The overflow will keep siphoning, which is why you need to make sure you have enough empty space in your sump to hold any water above the lip of the overflow box. You also need to make sure you have a one-way valve or holes drilled in the pipe where the water gets returned to the tank to keep a reverse siphon from happening. A reverse siphon will occur when the power goes out, and a vacuum is created from the return pump stopping and water will get sucked from your tank backwards through the return pipe, backwards through the pump and back into the sump. This will overflow the sump very quickly and you'll end up with a flood on your dining room floor! I learned this the hard way, don't forget a one-way valve somewhere along your return plumbing.

The only ways you can overflow the tank is if your overflow box gets clogged and the return pump moves too much water from the sump to the tank, or if your return pump is returning water faster to the main tank than the overflow can move water to the sump (which will result in a very slow flood). This is why you need to make sure that any water in the return area of the sump can be held in the main tank without overflowing it. For example, if the return area of the sump is two gallons, make sure you have enough space at the top of your main tank to accomodate two gallons of extra water. This way, the return pump will send all the water in the return area to the main tank, and will run dry (because the overflow is not working and can't send more water to the sump), but the main tank will not overflow because it had enough empty space to hold that extra water in case the overflow quit.

I guess what I'm long-windedly trying to say is that your sump has to be able to hold any extra water above the overflow box, and that the tank needs to be able to hold any extra water that is in the return section of your sump. You also need to put a one-way valve in your return plumbing to stop a reverse siphon.

[ryangina]

ok i think i get it know lol. have evough room in both tank and sump to accomidate the flow but not so much that it will over flow the tank or aquarium. it was something i thought if the power went out and the siphon stoped and you didnt overflow the sump when the power came back on it would over flow the tank because the siphon being stoped that was my thougts