Overflow box for 150 gal aquarium

[thoap]

Would anyone know how to calculate the proper gph for an overflow I'll be connecting to my sump tank. Also, does anyone know if they make a variable rate sump pump, so that you could adjust the gph to very closely match what the overflow is putting out. :confused:

[AW2EOD]

9 times out of 10, which ever overflow box you get, it will tell you what GPH it's rated for. Then, you just make sure, when you get your pump, that the GPH of it matches that of your overflow box.

For instance, on my 200gal. tank, I have an overflow box rated at 900 GPH. The pump, in my sump, is rated at 890 GPH. The calculations do not have to be EXACT...just definately make sure you get as close to matching as you can. If you can, go to a plant nursery/fish pond store to buy the pump. It'll be alot cheaper than if you bought it at a fish store.

Also, if you get a decent pump, it'll most likely have a dial on it that you can turn to either slow down or speed up the return rate.

[Xzibit]

Correct me if I'm wrong, but I think as long as the overflow is rated = or > the gph of your pump you should be fine. No matter how high the over flow is rated for it will only take as much water as your pump is pushing out. Also a pump rated for lets say 900 gph will not be pushing out that same 900 gph when you factor in how high you have to go from the sump to the tank and the lenth of travel of the hose.


X

[thoap]

Also, if you get a decent pump, it'll most likely have a dial on it that you can turn to either slow down or speed up the return rate.
I guess that I worded my question wrong. What I was wondering was how big of an overflow box to get for a 150. Since you have a 900gph on a 200, I probably should get something about that big. Is there a rule of thumb to go by to determine what the gph should be.

Also, AW2EOD, what brand of pump do you use in your sump? Does it have the dial?

Also, Xzibit, if your pump stops pumping, wouldn't the water from the overflow just keep coming and 'overflow' the sump? (unless you had one of the floats attached to shut it off).

[Xzibit]

Yes, it will keep comming until the water level is = or < the level at which the skimmer is. On my tank that will fill up my sump 3/4 of the way. You have to be careful though if your returns sit lower in the water then the skimmer box does and you pump shuts off they will start a reverse flow and fill it even more. I have a 900gph skimmer box on my 120 and a Magdrive 900 pump. With the distance it has to push the water i would say its about 700-750 gph and it works just fine. The skimmer box by nature can not take more water than it is given by the pump becaue it takes from the waters surface. However if you pump was pushing say 1000 gph and you had a 900 skimmer i would overflow the tank (assuming there is enough water in the sump to do so) or it would just drain the sump into the tank and fill it with lots of little bubbles as it sucks up air. Just watch your returns like I said, I went to clean and do a water change and I almost soaked my floor becaue I didnt realize what was happening.


X

[thoap]

Xzibit,
How many gallons is your sump and where do you have it located? (under your tank in the stand???)

[Xzibit]

Its about 20 gallons and located under the tank in the stand.