external pump with no bulkhead

[platax88]

Hello ... Is there any way to hook up an external pump without a drilled bulkhead on the sump. the pump is a Pan World 200 (1750 GPH) ... I was thinking of a something like this:

http://www.jb-portfolio.com/90_reef/no_bulkhead.gif

Thanks!

[DaveBrader]

that will work just fine, I have been running an external pump like that for a couple of years...

Dave

[h20cooled]

It would be hard to keep it primed, if power goes out and then comes back on it would most likely have to be re-primed and if you were not there you could burn up the pump. Not a good idea in my opinion.

Why not just drill the sump?

[DaveBrader]

Once it is primed, it will stay primed unless one end gets open to air, out of water. If both ends remain underwater, it will not lose prime...

Dave

[platax88]

yeah but if both ends remain underwater wont it siphon my display tank during a power outage... put a check valve on the returns?????

[comatose]

<a href=showthread.php?s=&postid=7988609#post7988609 target=_blank>Originally posted</a> by platax88
yeah but if both ends remain underwater wont it siphon my display tank during a power outage... put a check valve on the returns?????

NO! if both ends are under water what goes in one tube must come out the other end even in a power outage, you'll lose no water, it's a closed loop as long as both ends stay under water during a power outage.

No need for a check valve.

[ambaratur]

<a href=showthread.php?s=&postid=7988650#post7988650 target=_blank>Originally posted</a> by comatose
NO! if both ends are under water what goes in one tube must come out the other end even in a power outage, you'll lose no water, it's a closed loop as long as both ends stay under water during a power outage.

No need for a check valve.

Umm... are you sure? A closed loop has both intake and output in the display tank. This has intake in sump and output in display therefore it is not closed... it is an open syphon.

[platax88]

yeah because the return pipes will syphon back down until there is an air break in the syphon... that why people drill small wholes in their return pipes, right below the waterline ... correct?

But if i put a check valve, it will not allow the flow to come back down.

Also, will this setup, hinder the performance of my pump (GPH) vs... the bulkhead?

Thanks!

[ambaratur]

<a href=showthread.php?s=&postid=7988951#post7988951 target=_blank>Originally posted</a> by platax88
yeah because the return pipes will syphon back down until there is an air break in the syphon... that why people drill small wholes in their return pipes, right below the waterline ... correct?

But if i put a check valve, it will not allow the flow to come back down.

Also, will this setup, hinder the performance of my pump (GPH) vs... the bulkhead?

Thanks!

Check valves are nice but always have a chance of failure so I would recommend designing without one. Yes a syphon break is important in the return... the problem is just making sure your pump stays primed. If the pump is in the bottom U bend of the system I think it will always have water in it up to the height of the water in the sump.

If you use a large enough pipe for you input you should not notice a big slowdown in performance - but make sure you oversize it because otherwise you will cavitate by starving the pump on the intake.

[platax88]

ambaratur - that makes total sence! theres no way the water would go below the sump level! it will stabilize there at the same height both on the intake and return of the pump...

how much should i oversize the pipe. The pump has a 1" intake... shoudl i go with 2"??? just on the intake part right?

Thanks again guys

[comatose]

your right i thought you had both intake and return in the tank and was using it like a closed loop, my mistake.
correct, you need some sort of syphon break, most everyone (including me) uses a hole just below the watrline on the return side.
no don't use a check valve, they don't work well and can not be trusted.
your sump should be big enough to handle any back syphon that happens, it is in your best interest after you finish everything to cut the power to the pump to see if you have it set up correctly and that your sump can handle the back syphon without over flowing.

[Qwiv]

That will work fine, just oversize the piping and reduce it right before it enters the pump.

[platax88]

AWESOME! no drilling tank needed! i am so relieved. i will use this solution for the return pump and my skimmer in sump, therefore i will not need to drill!

Thanks

[RandyStacyE]

One of my tanks has a sump with an external pump without bulkheads. I have no desire to ever use check valves within the plumbing. It's just another thing I would have to maintain. Most of the time the check valve would be a restriction and at the most critical time it may not seal due to many different reasons.

I typically keep my return 'just' above the water line. When the electricity goes out, the siphon quickly breaks and what is in the line will equalize to the level within the sump. It's not that tricky.
http://www.randystacye.com/images/Hidden/plumbing1.gif

It's not a bad idea at all to have a T at the top of the return line with a threaded cap or plug for instance just in case for when you have to do some pump maintenance. Just a little water in the line and the pump kicks right over. Sure there will be a bit of air in the suction side of the plumbing, but it works itself right out rather quickly. I like to have a ball valve within reach above the pump.

I wouldn't say that this is the 'best' way to plumb a pump because I just don't believe it is. It works. In a way it can be compared to the difference between a siphon ovreflow and an internal overflow ... sort of.

[DaveBrader]

The original picture you showed.....
in the very first post of this thread, was a true closed loop. You would not need anything but the loop in that setup.

You are now talking about something completely different involving the sump...

Go back to the original post in this thread and do it the way it shows in that picture, it will work just fine... it will not lose siphon, it will not drain your display. It will perform perfectly to increase flow in your display without adding to the flow in your sump..

Dave

[DaveBrader]

The picture you posted in the first post of this thread shows exactly how the siphon would be if the pump was hanging behind your display or under your tank in the cabinet... the return would go right back to the display where the siphon draws the water from.

I actually have one like that in my display, and one like that from my sump going to my chiller. Whereever the siphon draws the water from, is where is should return to. That is a closed loop. If you siphon from one tank, and return to a different tank, that is no longer a closed loop.

Dave

[lakee911]

<a href=showthread.php?s=&postid=7988458#post7988458 target=_blank>Originally posted</a> by platax88
Hello ... Is there any way to hook up an external pump without a drilled bulkhead on the sump. the pump is a Pan World 200 (1750 GPH) ... I was thinking of a something like this:

http://www.jb-portfolio.com/90_reef/no_bulkhead.gif

Thanks!

Do you have an actual pic of how this worked out? I'd like to do the same thing. How'd you secure the suction plumbing from the pump to the sump?

Thx
Jason

[platax88]

Hey Jason... i decided to drill the hole instead, good luck!

[Reef_bones]

<a href=showthread.php?s=&postid=7988561#post7988561 target=_blank>Originally posted</a> by DaveBrader
Once it is primed, it will stay primed unless one end gets open to air, out of water. If both ends remain underwater, it will not lose prime...

Dave

I agree that would keep it primed but then the power loss would cause another issue.. Back syphon...Your anti-syphon hole would cause you to have to re prime due to sucking air to stop the back syphon...

[lakee911]

I'm scared to drill it! :lol: 3/16" glass. My sump is already built. If I crack it, or its tempered I'm F'ed!

Thx,
Jason

[GSerg2]

Jason, I don't have a pic of mine but I did the same thing on two pumps. It works fine. You do still need siphon breaks in your returns just like with any return pump or it will drain your tank when the power goes out.

It will not require repriming because the intake of the pump is below the level of the water in the sump so the intake of the pump is always wet. I used 1-1/2 PVC for a pump that has a 1" intake so as not to restrict in the flow. Good luck.

[lakee911]

Thanks, GSerg. How'd you secure the suction line from flopping around?

[RichConley]

<a href=showthread.php?s=&postid=8926291#post8926291 target=_blank>Originally posted</a> by Reef_bones
I agree that would keep it primed but then the power loss would cause another issue.. Back syphon...Your anti-syphon hole would cause you to have to re prime due to sucking air to stop the back syphon...

No, it wont. THe water will equalize to the level in the sump. Just keep the output above the water, and the input under the water, and you'll be fine.

[GSerg2]

Mine is all rigid PVC and is screwed onto the snout of the pump. It rests on the lip of the sump (30 gal Rubbermaid) as it goes over the top. I don't have it secured, it just sits there. I have a PVC cap over the end that I drilled full of holes to prevent sucking larger items (snails, rocks, etc) into the pump. Make sure it has lots of holes because you don't want to restrict the intake or your pump might cavitate. I know because it happened to me at first.