sump and pump question

[jfrank]

My little giant pump on my 75g crapped out the other day. The tank doesn't have anything live in it but sand right now so it's no big deal but I'm trying to figure out about replacing it. I picked up a Quiet One Pump (which is anything but quiet) for it rated at 780gph. I'm still sealing up leaks and all but what I'm noticing is that the pump is draining the return section of my sump faster than it can refill. Is my pump too strong for my sump or am I missing something here? The sump is actually just an empty wet dry. It's not real big but it's not tiny either... Maybe 10-20 gallons? Let me know what you think.

EDIT: and what about just scrapping the sump and running everything within the tank? 4 Maxijets in the tank would give me 15.7X circulation per hour. Plenty of live rock would be the filtration... Opinions?

 

[Brad]

Sumps are optional...you can do fine without one. IMO, you should try to keep the sump, especially if it is mostly there already. There's too many benefits to it.

You didn't mention what sort of system is returning water to the sump, but I'll assume it is some kind of overflow, gravity based system.

Since you can't control the maximum flow of the overflow, you have to slow down that sump pump. This can be done by putting a ball valve in the return line between the pump and the tank. You can just cut off the flow until the overflow is able to keep up.

You also didn't mention having any problems with the tank. If the sump pump was actually draining the sump faster than the overflow can suppy the sump...then your display tank is headed toward overflowing.

 

[jfrank]

Sumps are optional...you can do fine without one. IMO, you should try to keep the sump, especially if it is mostly there already. There's too many benefits to it.

You didn't mention what sort of system is returning water to the sump, but I'll assume it is some kind of overflow, gravity based system.

Since you can't control the maximum flow of the overflow, you have to slow down that sump pump. This can be done by putting a ball valve in the return line between the pump and the tank. You can just cut off the flow until the overflow is able to keep up.

You also didn't mention having any problems with the tank. If the sump pump was actually draining the sump faster than the overflow can suppy the sump...then your display tank is headed toward overflowing.

Yeah it's a hang-on overflow. I didn't consider the ball valve... that's a good idea. Might have to try that. I only had the pump running until it sucked the return dry... Then I shut it off and posted. Thanks for the suggestion.

 

[loganj]

You could also upgrade to an overflow with a higher flow rating. If you do install a valve on the pump, make sure it goes between the pump and main tank. If you put it between the sump and the pump, you'll have trouble with impeller cavitation and your tank will be full of bubbles.

 

[MarineFlake]

If the overflow is dual ported, make sure both lines are attached. Also, if the overflow is constantly 'sucking' then you should try adding another j tube for more water flow from the tank to the overflow box. Is there a valve on the overflow? If so, (And there should be..) then make sure to open it up. This is how you would adjust the water level in your tank (with the return pump at full blast). I cannot imagine there would not be one. 780gph is not what you'll get at 4ft. Assuming your 75G is on a stand, which puts the return (Head) at about 4ft. The flow rate is substantially lower than 780gph and according to the specs I saw on the Quiet One 3000 (rated at 780gph) you will get just under 600gph, looks more like 580 - 590 under optimal conditions (thats about 7.3 - 7.5 times/hr). There are many discussions about flow rate, that is, how many times an hour you should turn over the water in your tank. I have found from personal experience (Using a RIO 3100 wide open) that the tank stays practically crystal clear and the corals seem to like the higher turn over rate. A ball valve can be used to limit the flow of the return, but it typically leads to a never ending battle of fussing with it due to fluctuations in the water level of the display tank. I might also add that the back pressure is harder on your pump.
My $0.02
Best of luck!