Returning under the water line

[jimlad]

Hi all,
I'm getting a new 200l tank built and so i want to hide my drain and return in the weir box i also want my return nozzle to be 10" below the water line.
My question is "will a check valve on the return stop my tank emptying in a power cut?"... and can anyone recommend a decent return jet/ nozzle?

thanks Jim

 

[James77]

No, check valves are not reliable. You would want to drill a hole on the return pipe, just below the surface. The idea is to let air in to break a sipon should the power get killed. Even that is not without risk, as a stupid snail could be covering the hole right when you need it.

 

[billdogg]

^^^what he said^^^

there are those who use checkvalves, but IMO, they are risking a big flood. Checkvalves WILL fail. unless you clean them pretty much daily.

Oh - and drill 2 holes (best to have a spare) just below the waterline, and angle them so they shoot down.

 

[justinm0424]

I use a checkvalve without a problem. I've tested it multiple times and haven't had it even drip before. I have the return coming from the bottom of my 150 gal tank so i'm taking a huge risk but i believe check valves work fine. You could however use 2 checkvalves on the same line if you can fit them both in.

 

[jimlad]

Thanks guys!
I can appreciate that some people are for and some are against.
Has anyone ever heard of them slowing/ reducing the flow. I do feel why would they make them if they don't work but do the pros outweigh the cons?
What other methods do people use to return weather efficiently and quietly to the tank?

Thanks, Jim

 

[pmrossetti]

PLEASE don't rely on check valves. They will ultimately fail.

 

[Freed]

Someone posted a thread just last week about their check valve failing on them.

 

[justinm0424]

I have virtually no head loss. Plus for me I only need 2 feet of head since it's drilled right above my sump. If plumbed to the top of the tank i'd have over 6 feet plus all the 90's it'll take. Mine are angled also so if any sand or debris comes in it traps it onto the side so it won't block the flow. I planned on cleanning them every month but it's usually around 2. I just have threaded bulkheads and put a plug in them and remove them. They're the true union ones so it's simple.

 

[justinm0424]

<a href=showthread.php?s=&postid=15632744#post15632744 target=_blank>Originally posted</a> by Freed
Someone posted a thread just last week about their check valve failing on them.

Do you know where the thread is or what it's called? I've searched and googled but haven't found any threads about failed check valves or anything.

 

[kaskiles]

<a href=showthread.php?s=&postid=15632785#post15632785 target=_blank>Originally posted</a> by justinm0424
Plus for me I only need 2 feet of head since it's drilled right above my sump. If plumbed to the top of the tank i'd have over 6 feet plus all the 90's it'll take.

Wouldn't you still have 6 feet of head loss, unless the tank isn't filled up all four feet of depth? You have eliminated 4 feet of pipe friction and 'all the 90s'.

 

[Shane Hoffman]

If you use a check valve I would use two in series....If one fials you have a back up. Also filter your water right before it enters the pipe with the check valve to keep algae out of valve......

 

[Gary Majchrzak]

Re: Returning under the water line

<a href=showthread.php?s=&postid=15629679#post15629679 target=_blank>Originally posted</a> by jimlad
Hi all,
I'm getting a new 200l tank built and so i want to hide my drain and return in the weir box i also want my return nozzle to be 10" below the water line.
My question is "will a check valve on the return stop my tank emptying in a power cut?"... and can anyone recommend a decent return jet/ nozzle?

thanks Jim

design your system's plumbing so you don't need a check valve.
Follow the rules of basic good aquarium design.
Check valves will eventually fail- it's just a matter of time before they do.

 

[Macimage]

Re: Re: Returning under the water line

Re: Re: Returning under the water line

Originally posted by Gary Majchrzak
design your system's plumbing so you don't need a check valve.
Follow the rules of basic good aquarium design.
Check valves will eventually fail- it's just a matter of time before they do.

+1

 

[jimlad]

Thanks guys,
I'm torn between putting one in with a ball valve above it so i can clean it regularly or

just building a hood bog enough to hide the return back over the top... think its probably better safe than sorry on this one.
mum said i could have an aquarium not an indoor pool...
Cheers, Jim

 

[mnml]

I'm in the same boat as you as my return line is inside my display tank (about 3" below the overflow teeth).

If my sump can hold enough water from the DT once it drains pass the return, then is it safe for me not to drill any siphon break holes in the return?

 

[das75]

<a href=showthread.php?s=&postid=15630443#post15630443 target=_blank>Originally posted</a> by justinm0424
I use a checkvalve without a problem. I've tested it multiple times and haven't had it even drip before. I have the return coming from the bottom of my 150 gal tank so i'm taking a huge risk but i believe check valves work fine. You could however use 2 checkvalves on the same line if you can fit them both in.

wow and I though I was living on the edge having my ATO connected directly to my ro/di.

I have my return about 4" below the surface, no siphon breaks, no worries but then my sump can handle the backflow.

 

[maynardjames]

murphys law