People with wet/dry systems, please come in here....

[mapleredta]

That 72 gallon bowfront system I was given has a wet/dry sump under it. I tossed the bio-balls in the trash, and am in the process of getting it ready for set-up. If I were to guess the sump is probably 15 gallons, I will be getting the dimensions of the sump and getting the exact water volume within the next day or so. My question is about power outages. I know the water will drain down below the slots of the overflow and down into the sump. Is there a way to prevent a flood with such a small sump? We were thinking if the drain pipe was taller, less water would flow down.

Help me prevent a mess ARC!

 

[miami dolfan]

After 5 floods which ruined my hardwood floors(sorry honey) adding a 1" pipe to my overflow's bulk heads did the trick.

 

[cr500_af]

If you run your standpipes taller (higher level in the overflow box), you are correct. Less water will flow into the sump. Keep in mind that since most standpipes are not glued into the bulkheads, they will leak very slowly, meaning that if your power is out long enough your overflows will drain down below the level of the top of the standpipes.
Best thing to do IMO is set it up with the sump level very low, then kill the power and observe how much drains... if it goes up 3 inches, for example, that will tell you how much room you have to allow... plus I'd recommend a generous extra amount allowed for safety.

 

[michaelf1478]

cr500_af;459513 wrote: if you run your standpipes taller (higher level in the overflow box), you are correct. Less water will flow into the sump. Keep in mind that since most standpipes are not glued into the bulkheads, they will leak very slowly, meaning that if your power is out long enough your overflows will drain down below the level of the top of the standpipes.
Best thing to do imo is set it up with the sump level very low, then kill the power and observe how much drains... If it goes up 3 inches, for example, that will tell you how much room you have to allow... Plus i'd recommend a generous extra amount allowed for safety.

+1

 

[rbredding]

yeah... just modify the height of your drains to dial it in..... (I've got the same issue in my 90 - a relatively small sump)

 

[weaglereefer]

I have to disagree here, leave your standpipes alone, you'll want to lower the flow of the return pump. If you have lots of flow, the water level will be higher on the overflow teeth than if the flow were lower.

Turn all pumps off and fill the sump to an inch or so below the rim. Turn the return pump on and the water level should lower a bit. It should stabilize at some given height. If it gets too low (like right above the pump's inlet) you'll need to dial the pump back a bit til the level in the return chamber is at an acceptable level. Turn the skimmer on and the water level should lower a bit more. At this point you'll want to mark the water level or set your ATO float. This means that if there is a failure, the water will not overflow the sump. You may have to significantly reduce flow through the sump, but as long as you're getting 3-5x turnover per hour, you'll be fine.

 

[porpoiseaquatics]

Don't forget to put a backflow preventer on the return side. These tend to be several inches below the water level of the tank and will siphon backwards during a power outage. Learned this one the hard way.

 

[mapleredta]

porpoiseaquatics;459633 wrote: Don't forget to put a backflow preventer on the return side. These tend to be several inches below the water level of the tank and will siphon backwards during a power outage. Learned this one the hard way.

Great information. I think will set it up out side and do some test runs. :up:

 

[weaglereefer]

Don't rely on a check valve. Your return uses PVC and Locline, right? At the PVC elbow, drill a 1/4" hole. This will shoot a bit of water inside the overflow, but is not a major issue. It will act as a siphon break if the power goes out. When the power returns, some bubble will squirt into the tank, but those are usually gone in a minute or two. I think there are a few members here with bad check valve experiences.

 

[mapleredta]

I'll get some pictures of it tonight and post them up.