Sump overflowing when power is off

[roadster33]

I have just converted to a pentagon reef tank. It was custom made and I believe it is between 75-90gals. My dilemna is I had the tank built with a built in overflow.
The overflow goes into my Del Rey 125 wet/dry system. However, tonight testing the system, I shut off the power to simulate a power outage and the wet/dry overflowed.

There is nothing in the tank right now.
Will my system work when I start to add my live rock and live sand? or I am missing something....

Please help

Pentagon Tank (actual gals not known)
Rio Hyperflow 17
Del Rey 125 wet dry system

 

[DaveM]

Well you did the right thing by testing that first. I had a similar problem when I first started. Either the sump isn't large enough or you have to much water in system. I concurred mine by spending ten bucks at lowes on a check valve to keep water from back filling the sump. Hope this helps

 

[austinsdad]

Yep. One of two things. The sump has too much water in it. Not unusual to only fill sumps only half to 3/4 full. If your tank is drilled, maybe the return pipe needs a siphon break hole in it so that it not only returns the water in the supply line when power goes off, but it doesn't suck more water out of the main. If that's it, drill a small hole in the hard return pipe just below the water line.

Check this thread out. http://www.aquariumadvice.com/forums/f11/siphon-break-help-21945.html

 

[tjm80]

+1 on the siphon break. I overlooked that very, very critical step.

Luckily I caught it after it spilled out only about 2 or 3 gallons.

 

[roadster33]

update

I just purchased a check valve on the return line with stop valve to control the amount of water flow.

I am interested in the siphon break...could you give me a diagram? The tank is custom built with overflow that goes to my del rey sump below my tank. The return is pumped back by a rio hyperflow 17 (4 ft return line back to tank so waterflow was calculated to be 800gph).

Am i missing something as I never had a overflowing sump problem in my previous traditional 50gal rectangular tank with del rey 125 system?

Back then , I even had my protein skimmer hooked on the sump for a more aestethic appeal (no parts sticking out). Never once a overflow problem...don't know if it is due to my overflow box was a small 5x5 black box with grates.

Your input is needed


TIA

Pat

 

[austinsdad]

Not near a computer but I'll try. Your return line, is it that lok line stuff the bends and flexes? Anyway, the horizontal pipe that sits under the water after the 90 degree turn in the return box. That submersed line can suck water when the power goes. A small hole drilled barely below the water line makes a siphon break as it sucks air instead of water.

 

[David S]

next time you test,turn off everything first then start filling via the DT to the highest point in the sump you want it to go in a power cut,and make sure you drill the return line as stated,the return pipe from the pump in the sump needs 2 holes drilled into the pipe( just in case one gets blocked by algae,snail etc.)To get the correct position for the holes fill the system as stated then just above this water level in the DT drill the 2 holes in the return pump pipe.Test the system by turning everything on,when all running correctly mark the water level on the sump and again mark it when everything has been turned off,this will give you the levels to top up(bottom line whilst running) and top line PWC when not running

Hope this helps

 

[roadster33]

fixed

It is solved - adding a check valve on the return line solved the problem.

Also, as I was working on the plumbing issue, I thought I should add a gate valve to allow more control/access to the sump.


Thanks for all the help

 

[melosu58]

Moved to General Hardware and equipment discussion.

 

[mr_X]

check valves are not 100% effective. very shortly they get slimy stuff/tube worms/fan worms/starfish..whatever in them and no longer seal 100%. i would drill the hole below the water line also.

 

[roadster33]

Drill a hole?

Drill a hole below the water line where?
The drain and return lines are through the custom overflow.

If I drill the hole on the return line in the overflow. From the sump - return bulkhead - vinyl return line - spray/output.
Wouldn't I lose pressure going out?

Sorry but I haven't heard/done this before...

 

[mr_X]

the hole should be drilled in the return line just as it enters the water. the spray output. it will not even be noticeable, as far as pressure is concerned. when the power goes out, the water level will drop and that hole will suck air and break siphon almost immediately.