Explain check valves to me and do I need one?

[HighChiefKC]

I see these on some builds, and some I don’t. I’m getting ready to plumb my new 225 with sump. My old 180 I never had any of these. I just had my return lines high enough in the water, that if power went out it only drained enough that my sump could handle it. Is that still a reasonable idea? Been out of hobby for almost 15 years.
If I need check valves do I install them vertically on each return line, or do I just need one installed horizontally before it Tees to 2 returns?
thanks!

 

[JoshH]

Plumb it the way you always have. You don't need check valves, atleast IMO they are a complete waste of money and time. A properly designed plumbing setup will never need check valves as the sump should handle any and all back flow from the tank if the pumps are shut off.

The only time I would ever suggest check valves is if you were running dual return pumps on the same return line..

 

[Silver14SS]

It's one more maintenance item, if you can run your plumbing without them, I see no reason to add them. If you decide you want them, I recommend using unions so you can remove them easily.

A diagram of your plumbing would help . You should be able to do one right after the return pump if you have a vertical section there.

 

[Super Fly]

This is one of those subjects that many folks will agree to disagree... if u decide to put one in, it should be vertical. They have union check valves that r easy to remove for cleaning.

True Union Check Valve

Spears makes the highest quality True Union check valves. Use them to add a last line of defense against overflows. Check valves allow one directional water flow and are used to prevent back siphoning. They are commonly used on return pump outputs to prevent water overflowing the sump in the...

www.bulkreefsupply.com

 

[Silver14SS]

This is one of those subjects that many folks will agree to disagree... if u decide to put one in, it should be vertical. They have union check valves that r easy to remove for cleaning.

True Union Check Valve

Spears makes the highest quality True Union check valves. Use them to add a last line of defense against overflows. Check valves allow one directional water flow and are used to prevent back siphoning. They are commonly used on return pump outputs to prevent water overflowing the sump in the...

www.bulkreefsupply.com

I agree, they "should" work horizontal, but if I used one, I'd sure prefer to have it vertical.

 

[Codiak]

For the price and effort of including a check valve, why wouldn't you? A siphon break is for poor people and a check valve is pure piece of mind.

 

[W1ngz]

A well designed plumbing setup can incorporate both siphon break and check valve, and use the advantages of each.

A wye check valve is easy to clean (but you should still have unions anyway).

When it's all working and clean my return nozzle stays just below the water line, so there is no splashing or air belching out of the line on pump restart after feeding, and the water line stays just at the weir on my overflow so the overflow box begins filling immediately on pump start. Normal flow takes under 15 seconds to quiet down and stabilize.

 

[Admann]

My 2 cents, if you use a flapper type it should be on the horizontal as they can hang in the open position on the vertical due to bio or trash buildup

 

[kschweer]

If thought out and plumed correctly there is no need for a check valve. They provide a false sense of security as they can and will eventually fail, where as plumbing the return just under the water surface and leaving enough room in the sump for any excess water works every time. Take your time and plan things out.

 

[Admann]

If thought out and plumed correctly there is no need for a check valve. They provide a false sense of security as they can and will eventually fail, where as plumbing the return just under the water surface and leaving enough room in the sump for any excess water works every time. Take your time and plan things out.

I agree check valves will fail. Check valves are designed to minimize backflow not eliminate it, unless specifically stating they are bubble tight.

 

[ironman187]

For the price and effort of including a check valve, why wouldn't you? A siphon break is for poor people and a check valve is pure piece of mind.

False. Check valves can and do fail or get clogged. Syphon breaks are more reliable. Really, a check valve is cheap, it has nothing to do with price. Smh.

 

[Gw2kpro]

For the price and effort of including a check valve, why wouldn't you? A siphon break is for poor people and a check valve is pure piece of mind.

Not following this line of thought. Check valves aren't exactly a high dollar item.

 

[waterskiguy]

I always just use air gaps created by a 1/4" John Guest Fitting, in the top of the return lines, to break siphon. The outlet dumps right behind my overflow, so I can always see the flow, to make sure they don't get clogged. I haven't had one clog in the last 8 years though.

 

[RocketEngineer]

Let’s explain WHY check valves fail. In order to work, a check valve uses a movable device ( a ball, a flap) which engages a seal when the flow through the valve stops/reverses. The issue boils down to this seal existing in a biologically active system (our tanks) where several different types of organisms grow on any and all available surface. Whether it’s a sponge, tunicate, or feather duster worm, all it tanks is some random organism taking up residence on that seal to cause the check valve to fail. No amount of cleaning is going to 100% remove this issue.

By comparison, having returns close to the water surface that quickly pull air into the return to break the syphon relies on nothing more than physics. As long as there is water coming out, air can get back in. Simple, fail safe.

Check valves have no place in a reef aquarium IMO.

 

[Greybeard]

Keyword... need. No. You don't need one.

Regardless of having or not having check valves, you can't count on them. They will fail. Every, single, one. No doubt about it, they will fail. That said, you can't design a system that requires them, and be safe.

So, if you design your system so that it doesn't need one, as you must, considering that they will fail, why would you want one?

When they work, they can stop back flow immediately. Faster than venting, etc. They'll keep tank levels and sump levels closer to normal than they would be without them. Startups splash less, and take less time to normalize. It can make startup quicker and easier.

Do you want one for that? Your call. I'll never plumb one in again, it's too easy to count on them, think you're safe, and disaster is one little snail shell away.

 

[ca1ore]

Sometimes the less expensive option is also the smarter option. Putting the return outputs close to the water surface is 100% fool and fail proof. Most experienced reefers use this approach. In addition to the tendency to fail, check valves also add back pressure to the pump. Singularly pointless in my experience.

 

[Sisterlimonpot]

Let’s explain WHY check valves fail. In order to work, a check valve uses a movable device ( a ball, a flap) which engages a seal when the flow through the valve stops/reverses. The issue boils down to this seal existing in a biologically active system (our tanks) where several different types of organisms grow on any and all available surface. Whether it’s a sponge, tunicate, or feather duster worm, all it tanks is some random organism taking up residence on that seal to cause the check valve to fail. No amount of cleaning is going to 100% remove this issue.

By comparison, having returns close to the water surface that quickly pull air into the return to break the syphon relies on nothing more than physics. As long as there is water coming out, air can get back in. Simple, fail safe.

Check valves have no place in a reef aquarium IMO.

exactly how I would explain it. You can't argue with any of that. One clever idea that I saw for breaking the siphon to the sump during power outage is the reverse check valve:


Although it will still need to be serviced often, it is easily accessible.

Now with all that said, these days with DC powered return pumps having battery backups as well as the ability to program a slower speed during feeding to keep the pipes primed, a revers check valve isn't worth the hassle.

 

[Nick30G]

Yea dont use check valves. Your going to really hate yourself when you come home one day and have many gallons of water all of your floor due to poor planning on your tank and the failed check valve. All you need to do is get a decent sized sump relative to your display tank size, and have your return pump output nozzle right at the water's surface so it immediately breaks siphons during a power outage so it back siphons the least amount of water possible. Also account for the few inches of water that is running over the overflow teeth and the amount in your overflow box. This method always works and requires no matienece, a check valve dosent work all the time.

 

[Billdogg]

I will agree with all the wise gentlemen who don't use them. Never had one, never will. I've already got too many things to clean and I won't intentionally add more.

Use one if you want. Just don't expect it to work when you really need it to - like right after you leave for vacation.

 

[jschultzbass]

You don't need them but I LOVE having mine for the reasons @W1ngz mentioned. I'll never plumb a tank without one. If it fails, I still have it plumbed in a way that my sump won't fill up before the siphon breaks. I've had tanks with and without but after having with, never looking back! Necessary? No. But to me, definitely worth it. I have no idea why there is so much hate on this thread for them...especially if used correctly (meaning not the sole safety)