Backflow flooding problem

dmbnpj

New member
My power went out today. My tank backflowed into my sump and overflowed. I had about 1/2 inch of standing water in the base of my cabinet. I have a 75 gallon tank with a 10 gallon refugium and about a 15-20 gallon sump. I normally keep the water from 1/4 to 1/2 way high in the sump. I also run a ASM G3 skimmer in the sump(couple gallons of water in that too). I have had the power go out before with no problem(obviously I had less water in the sump those other times). How can I prevent this from happening again?

Thanks for any help!
 

crumbletop

New member
You can adjust the ends of the output lines so they are not as low in the display tank, thus breaking siphon sooner and letting less water flow back to the sump. That's what I do. Another option I have heard of is drilling a small hole near the top of the in one of the return lines -- again to break siphon to prevent backflow. You can also put a flap valve in the return line but this doesn't prevent all back flow, adds resistance to the line reducing flow, and needs to be cleaned from time to time. HTH

Jack
 

jdieck

New member
Just must keep the sump empty enough to receive any excess water draining from the main and or equipment.
Also check that your return line is not syphoning back. Drilling a small hole in the base of the return line will help prevent the syphon, in addition a check valve in the return line will help prevent the line to wmpty preventing bubbles when the pump restarts.
See the folloing diagram:
18470Drain.jpg
 

AZDesertRat

In Memoriam
Don't waste your time and money on a check valve. They are a mechanical device and although simple they will fail eventually. They get the same stuff you scrape off the tank glass and that collects in the sump inside them and they will never seat fully after a short time.
Your best option is to never fill your sump above thet certain point no matter what. Un plug the pump and play with it until you establish that point and then paint it or use a sharpie and mark it directly on the sump so you never ever and I repeat EVER fill past that point. If you do Murphy will be looking over your shoulder and cause a power outage that evening when you are in bed or away from home.
You can also drill 2 small air break holes in the returns. Use a small drill bit and drill holes so they are normally jsut under the surface and when water draws down past that point they suck air and break the flow. The problem with these is they get dirty if you don't remember to clean them out regularly and then it doesn't work.
Best bet is establish the sump level and stick with it. Remember if you lower the returns like is possible with LocLine the level will change so figure out what could be worst case and use that point.
 

dmbnpj

New member
Ok, that kind of sucks....that low level in the sump requires a constant checking on because my evaporation level is really high and I have 2 pumps in the bottom of the sump which cannot run dry. So when I go away for a couple days I normally just fill the sump as high as I can (bad idea I know, I've just been taking my chances). I guess I need to look into a float valve or something that will automatically add water from a 5 gallon jug when I need it and keep the water level below that "safe line."
Cool, I thank you all for the replies!!
 

jdieck

New member
<a href=showthread.php?s=&postid=7525383#post7525383 target=_blank>Originally posted</a> by AZDesertRat
Don't waste your time and money on a check valve. They are a mechanical device and although simple they will fail eventually. They get the same stuff you scrape off the tank glass and that collects in the sump inside them and they will never seat fully after a short time.

Az I use both a check valve and the orifices in case it fails.
The reason is that I turn off my pumps every time I feed. If I do not have the valve the line gets empty and when I restart the pump I have an aquarium full of air bubbles and lots of slimy corals.
BTW, even as I expect it to fail it has not and has been running for the last four and a half years. I think that because the lack of light inside, the stuff accumulates very slowly or because I turn it off and on at least once a day it keeps it functional.

So as far as the syphon breaks are there I also recommend the installation of a check for that reason
 
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