Check Valves?

[saltysteven]

Does everyone use check or no? I dont see them on to many systems and i was wondering how would you keep the water from syphoning out if you didnt have one. Or is the sump so big it can handle the extra water?

I have about 30 feet of 1.5 in pipe plus my exits sit into the water about 3-4 inches.

Is there anything bad about using these valves?

[MalHavoc]

check valves fail. You design your system so it can handle the backflow, and you also drill small holes just below the water surface in your return lines so when the power goes off and the water drains, the minute it hits those holes, the siphon breaks. Drill a bunch of them. Maybe a quarter inch below the water surface.

[AZDesertRat]

Don't ever rely on a check valve or drilled holes either one, both fail. Check valves are designed for pristine fresh waters and not saltwater or an aquarium with fish wastes, food, snails, algae etc. Driled holes get covered by algae, flake food, a snail etc.

The best possible solution is keeping the returns close to the surface so you backsiphon or drain a small calculated amount of water back to the sump in a power outage. That and always maintaining sufficient room in the sump for that amount plas a little fudge factor is the only sure way to prevent floods.

My tank is a100G and I have a 30G sump. I know in a power outage I siphon less than 4 gallons of water to my sump so to be safe I keep at least that amount plus some available even when topping off the sump.

[saltysteven]

wow - i think im going to need a bigger sump

[AZDesertRat]

Why so much pipe and so big? Is the sump in a basement or something? 30 feet is a lot even for a basement location?

[AZDesertRat]

Why so much pipe and so big? Is the sump in a basement or something? 30 feet is a lot even for a basement location?
Even so 30 feet of 1.5" pipe only holds 3 gallons of water so thats not that big a deal. If you keep your returns close to the surface you should only drain down to about the bottom of your overflow teeth or maybe another 3 or 4 gallons so if you kept 8 gallons or so free you would have plenty of room. You have to experiment on exact volumes but I''ll bet I'm close.

[stagger19]

I have a simalir issue, Im getting ready to drill my 55. My stand will only allow me to use a 10" wide sump, plus I dont want to sacrifice the whole cabinet for a sump, so im using a 12 gallon (same footprint as a 10, just a lil higher) for my sump.

I have to be careful with the returns as AZDesertRat mentioned.

A smaller sump can work, as long as you are careful on your planning, and allow more than enough room for error u should be fine.

be sure to calculate and allow for all the water in your piping, as this will drain back into the sump if the power fails

[Blown 346]

I have had a check valve on my 125 for over 4 years now withouyt failure. Basically when the check valve is engaged once power is lost, the retunr pump stops pumping water to the tank. The check valve closes from the water running back down towards the sump. The water level you have ion the sump and the tank stay the same.

[saltysteven]

the tank is in the basement and the pumps and sump is piped into the next room. its a 117 gallon cube and i have a well im not exactly sure how big the sump is maybe around 25 gallons. the way i just had it setup was like you have explained with keeping the exits up high- i was just curious about those check valves.
Could they hurt if i throw one on for extra protection? (in case somehow the exits get moved lower by accident)

[stagger19]

sure, they cant hurt, any extra protection agaist a flood is better than not enough.

[AZDesertRat]

They will cause a head loss restriction in the return piping. Depending on the type it can be equal to several feet of vertical lift added to the discharge so the flow will drop. At a minimum it will be equal to one or two fittings added to the head loss calculation. I wouldn't waste my money and I deal with valves for a living.

[Blown 346]

<a href=showthread.php?s=&postid=11137847#post11137847 target=_blank>Originally posted</a> by saltysteven
i was just curious about those check valves.
Could they hurt if i throw one on for extra protection? (in case somehow the exits get moved lower by accident)

I dont see how they can have a negative effect. They will stop the sump from overfilling, if the return pump or the power goes out. As far as restriction, like said above they will restrict flow a little bit. I myself will always use one after my return pump failed and my sump overflowed 30 gallons of water on the basement floor. They are a cheap investment, what can they hurt?

[Playa-1]

I don't think check valves have any place in a salt water environment.

[Macimage]

Check valves will fail for all the reasons that AZDesertRat mentioned (fish wastes, food, snails, algae, etc.).

The reason that you don't see the mentioned much on this site is because it is far better to design your system so that it functions without them.

I don't believe I've ever seen a Tank of the Month with check valves. TOTM tanks are the best designed in the world and I'd take note of the fact that they usually don't have any check valves.

Joyce

[saltysteven]

yea ive noticed the tank of the month guys never have this on but then again they have huge sump systems. ill just have to come up with enough water space in my sump somehow. i was thinking worse comes to worse i could just pipe another 30 into my sump. this would make enough room for water but would be a bit backwards in sump building but would save me money instead of buying a 75 gallon and making a new sump

[AZDesertRat]

You should have plenty of room in your existing sump. I maintain 6 to 8 gallons of freeboard in my 30G sump and top off 5 to 6 gallons evey 4 days with no problems. You don't have to keep the sump clear full.

[saltysteven]

your probably right i do have to check it out. im going off of memory right now since i stopped the running tank for piping remodel. (its a new tank with nothing in it)
i think if i keep those exits up it should be fine. the water from my skimmer also gets blown into the sump at power off as well.
So no check valve- okay

[wizzbane15]

I agree on the no check valve. I had one fail last summer and my tank back siphoned and over-flowed my sump:

Result: I need a new floor.

I drilled a hole at the top of each of my returns and have since removed the check valves. If you drill holes, don't forget to test it because there will be a little bit of water that back siphons into the sump.

[meco65]

Make it a habit to clean the siphon prevention holes when doing glass cleaning, they wont get stopped up that way.

[AZDesertRat]

Correctly placed returns = no maintenace. Drilled holes = maintenance?