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doch
02-08-2005, 06:14 PM
Out of curiosity, not to mention a little bit of 'cover my butt' has anyone ever had any problems with inline check valves failing on their return lines? I would like to get a return line coming in around the bottom of my tank to get a good amount of flow going through my rocks, but am worried that if the power goes out the checks may fail... or even just leak through enough over say a 12 hour shift to flood my place :eek: . Somewhere along the way I have heard that checks can't be fully trusted... is this true? If so is there a brand or style that is least likely to have me end up with a very large bill? What about a redundant system of 2 in-lines?

muck
02-08-2005, 06:26 PM
HAHA! Tricked you:

??


Why not just drill the tank for a closed loop with the return near or in the bottom of the tank. No worries about it failing that way. :cool:

Delphinus
02-08-2005, 06:34 PM
I'm not a real big advocate of check valves as a fail-safe mechanism.

In my experience, check valves can place enough back pressure on the pump to cause a noticeable loss of flow. Further, I think it is a question of "when" not "if" it will fail. All our plumbing, the pipes get coated with a slime over time, that will eventually cause the seal to fail in a check valve.

Thus the only way to keep check valves is to routinely clean them out. Thus it's another maintenance chore to keep on top of, and further since it tends to be an "invisible" task (you don't "see" that the check valve is dirty unless you look inside), human nature being what it is, I think the risk is that it will tend to be ignored at some point or other.

Depending on how you have your plumbing, there are ways around having to need a check valve to prevent overflowing your sump.

The first method is size your sump to accomodate all the extra water that drains into it in a power fail scenario.

Along those lines, also make sure your returns are near the surface of the display tank(s) so that the tank(s) don't empty beyond a couple inches off the top in a power fail scenario. Sounds like common sense, but you'd be surprised how many people put sump returns down near the bottom of the tank. :eek: (In that situation, you're completely reliant on the check valve, and it "must not fail." But there's no way to guarantee this: by cleaning the best you are doing is "hedging your bets." How comfortable are you with risk?)

The last idea I want to share is that if you have your sump return lines come "up and over" the tank wall, if you drill a few holes in the pipe near the surface, these will serve as siphon breaks. As soon as they suck air in a power failure, the siphon is broken. This idea isn't foolproof, nothing really is, but at least you can spot at-a-glance if the holes are clogged and clean them out with a minimum of fuss.

Just my $0.02. HTH.

Coralquay
02-08-2005, 07:16 PM
Good Lord Tony wrote a novel again.... :mrgreen:

Delphinus
02-08-2005, 07:17 PM
Uh ... Welcome to Canreef. (I think.) :lol:

AJ_77
02-08-2005, 08:28 PM
Good Lord Tony wrote a novel again.... :mrgreen:
One post and you seem to have a grip on the place... :lol:


You go, Tony!! :biggrin: :cool:

Chin_Lee
02-08-2005, 08:50 PM
do not rely on check valves. they will collect gunk and are considered very unreliable in our hobby. many stories of flooding when relying on this method.

monza
02-08-2005, 10:19 PM
Never used a check valve, but I hear if you replace them once a year they can work 'most" of the time.
Dave

danny zubot
02-08-2005, 10:36 PM
To solve your problem. Get rid of the check valve for starters, they do reduce your flow as stated above. You can drill a 1/8 or 1/4 inch hole near the top of the return tube/pipe just under the water. When the power goes out and the level drops by an inch the siphone will break because of that hole.

Nemo
02-09-2005, 06:24 AM
I run check valves in my system.

1. clean them every time you do a water change, they have built in unions, take the ball out and wipe it off and wipe out the seat.

2. they do not reduce the flow, the check valve is a lot larger than the pipe size it conects to. This is to allow ( in my case) a full 3/4" of flow around the ball, so the 3/4" line is always full.

3. If you ever decide you do not want the check valve in your system, take the union apart remove the ball and what you have left is an expensive union.

4. you can always decide to drill your return pipe in the tank at a latter date, but you can not decide to un drill a hole.


Robert

Willow
02-09-2005, 06:32 AM
surley it's easier to just have a sump that can take to volume of water from the plumbing and overflow no? nothing to clean and no worries about floods.

EmilyB
02-09-2005, 06:39 AM
Tried a check valve once...it sounded horrible. :eek:

danny zubot
02-09-2005, 02:24 PM
surley it's easier to just have a sump that can take to volume of water from the plumbing and overflow no? nothing to clean and no worries about floods.


Agreed, but in this case the return pipe goes to the bottom of the tank, I don't think anyone wants that big of a sump.

doch
02-09-2005, 10:09 PM
Precisely. This whole question came up when I decided that I want water flow through the bottom portion of the tank (and have a pump but not a powerhead). As it is now, my 33 will take the drainage if a failure should happen, but 90 gal of water rarely fits in a 33. I like the idea of the hole drilled just below the surface... not sure how I didn't think of that as that is how I have my other return line set up... but that should solve my problem... thanks all!!!

Delphinus
02-09-2005, 10:11 PM
Another idea to consider for low lying outputs, is to go closed loop instead of via sump return...

muck
02-09-2005, 10:15 PM
Another idea to consider for low lying outputs, is to go closed loop instead of via sump return...
Isn't that what I suggested already... :rolleyes:

Thats the way i will be going on my next tank.
Less flow through the sump more flow in the tank. :mrgreen:

doch
02-09-2005, 10:15 PM
Call this a stupid question if you will... but what is meant by cloesed loop? An inline pump? If so.. I already have a submersable... and budget is the key word today... so....

muck
02-09-2005, 10:27 PM
For a closed loop you would need a seperate pump.
The pump pulls the water out of the tank where ever you put the intake line and puts it back into the tank where ever you put the return line(s).
There is no worry of it overflowing your sump because it doesn't go there.

Tank -> Pump -> Back to Tank

Its a great way to get more flow in your tank without having all sorts of powerheads to clutter it up. You can also drill the bottom of your tank and hide the return line(s) among rock piles or whatnot.

HTH

Delphinus
02-09-2005, 11:17 PM
Another idea to consider for low lying outputs, is to go closed loop instead of via sump return...
Isn't that what I suggested already... :rolleyes:

Thats the way i will be going on my next tank.
Less flow through the sump more flow in the tank. :mrgreen:

Sheesh Muck, I was seconding your suggestion... :razz:

monza
02-09-2005, 11:55 PM
Don't think that a closed loop guarantees you can plump low and not have your tank drain. At least I would not build my tank that way. Ever had a pump lose a seal or malfunction, I have. On a closed loop with low plumbing I would have drained my entire tank to the floor. IMO it is just a risk having the plumping to low. On my new tank it is drilled high on the back and returns and outlets take a 90 degree bend downwards to what level I want. At the 90 I have the small little holes drilled to break the siphon. I never want to see 340g. on my floor. (knocking on wood)

Dave

muck
02-10-2005, 12:04 AM
Sheesh Muck, I was seconding your suggestion... :razz:
http://www.muiscontrols.com/ryan/thumbup.gif

Delphinus
02-10-2005, 03:27 AM
Don't think that a closed loop guarantees you can plump low and not have your tank drain.
I don't think anything is really truly foolproof. Every idea has pros and cons, risks and rewards. I would hope that the likelihood of a pipe leak is less than that of a power failure/interruption. So I think a closed loop is less risk than a sump return; but I agree that it's not zero risk. :smile:

Willow
02-10-2005, 03:29 AM
Don't think that a closed loop guarantees you can plump low and not have your tank drain.
I don't think anything is really truly foolproof. Every idea has pros and cons, risks and rewards. I would hope that the likelihood of a pipe leak is less than that of a power failure/interruption. So I think a closed loop is less risk than a sump return; but I agree that it's not zero risk. :smile:

don't discount the possibility of a bus hitting the tank during a water change.

doch
02-10-2005, 03:34 AM
So... Here's my latest idea in thinking about this.... let me know what you guys think. How about a closed loop, with a submersible pump in a self contained container that is as high as the tank, and as low as the bottom of the sump. Pump sits in the bottom of it, and no matter what, as long as the plumbing is good the level could only get to be as high as the top of the tank level normally is. My only concern with this: How much would it cost to build such a vessel? It would need to potentially have a great deal of pressure on the bottom of it, so maybe 6" Acrylic? How much does that stuff cost? Anyways, just a thought.

monza
02-10-2005, 04:35 AM
doch.. I don't know what your saying!
I'm just glad I'm not on a bus route!! :biggrin:

Dave

Richer
02-10-2005, 04:39 AM
Check this link (http://www.melevsreef.com/closedloop.html) out for ideas on how to stick a closed loop on your tank. You don't have to use a SCWD on there to make it work.

-Rich

Delphinus
02-10-2005, 05:36 AM
Oh great, thanks Willow, now I'll never get to sleep. ("Is that a bus I hear outside ?????? :eek: )

mr_alberta
02-10-2005, 07:10 AM
So... Here's my latest idea in thinking about this.... let me know what you guys think. How about a closed loop, with a submersible pump in a self contained container that is as high as the tank, and as low as the bottom of the sump. Pump sits in the bottom of it, and no matter what, as long as the plumbing is good the level could only get to be as high as the top of the tank level normally is. My only concern with this: How much would it cost to build such a vessel? It would need to potentially have a great deal of pressure on the bottom of it, so maybe 6" Acrylic? How much does that stuff cost? Anyways, just a thought.

Would the purpose of this container be to hold water if the pump ever breaks a seal or the pipe from the closed loop breaks?