Need to improve flow into sump

[pugmommie]

We just finished plumbing our tank and did a water leak/flow test. Looking for some suggestions on how to improve the flow from our 120 Gal reef ready tank into the sump. Sump is in a room located behind the tank. We have two 1 inch bulkheads in the tank with one going into the skimmer area and the other into the refugium, their is a third 1 inch bulkhead in the center for a closed loop. We have an Ehiem 1262 for the return pump located in the center of the sump. We can only open the ball valve on the return pump about a quarter of the way to prevent the display tank from overflowing and this does not provide much of a flow back into the tank. It just seems that it is not coming out fast enough from the overflows.

 

[Hop]

Are the tops of the stand pipes on the backside of the tank completely open? The pics are over exposed and I can't tell...

 

[pugmommie]

Yes they are open, not capped.

 

[Hop]

OK, next item that I saw was that it appears both drains are submerged 6" or so in the sump? This can cause back pressure that could be an issue...

 

[pugmommie]

Tried that, removed the pipes so it would free fall straight into the sump, helped a little but still pretty slow.

 

[Hop]

Is it possible that the drains are too high in the tank? Turn the elbows in the tank 90 degrees and try it again. In theory, the drains should be able to come close to handling the pump. I would expect some throttle back, but not more that 1/4 closed, not 1/4 open...

 

[pugmommie]

ok I'm gonna try that now and will let you know.

 

[Hop]

Or just take the elbows off completely... for a test that is.

 

[pugmommie]

I opened the ball value on the return pump all the way(maybe to much at once) and had the drains turned inside the tank but the tank still filled up.

It does seem to empty better when the overflow strainers are off but I thought those would be important so fish don't get sucked into the sump.

now i'm gonna try it with the 90degree elbows off the overflows and just the strainers screwed in to the bulk heads.

 

[Hop]

Leave the elbows on and start with the valave on the pump and the 1/4 open position. Then go to 1/2 and see where that puts you. See if you can open it up more...

 

[Hop]

As far as the strainers go, I don't trust them since as they get dirty, they slow We'll tackle this issue, then I can show you some C2C mods that may be to your liking...

 

[pugmommie]

Took the strainers off the overflows and now they get a nice vortex going over them. It looks like the most the ball value can be opened on the return is 1/2. If you open return any more then the sump starts to get lower in the middle and level starts to raise in DT.

We do have a ball value and a union on each of the returns on the sump side and we were thinking they might be causing enough flow restriction to be causing us this problem.

It seems my husband is sawing them off as I am typing.

 

[Hop]

OK... They certainly can add friction... Getting up to 1/2 is good... We are making progress

 

[pugmommie]

I think 1/2 on the return might be the right flow into the DT for us. The over flows seem to be a little faster with the union and ball values off.

I think we're done for the night now. The bulk heads on the back of the tank are getting little drips from us messing with them and we are going to drain tank till water is under the bulk heads for the night and then work on it again in the am.
We are interested in the mods you mentioned in place of the strainers.
Thanks for all your help tonight.

 

[Hop]

No worries... Hope it helps, I'll be around tomorrow I'm sure And there will be plenty of plumbing gurus!

 

[billdogg]

IMO, 2 x 1" drains is kinda on the small side - they will handle about 300gph each safely, without creating an actual siphon. the 1262 is putting out, i think, about twice that. I would consider redrilling for larger bulkheads - 11/2" would be good, or even 2". this will allow for more than enough drain for the 1262 to run wide open, and still leave a little wiggle room for the inevitable blockage that will occur. With the 1" drains, if anything at all restricts the flow out, you will have a flood/waterfall out of your tank.

JMO (I have 2x1" and 2x 2" drains for my 150)

 

[pugmommie]

Billdogg, What do you mean by "without creating an actual siphon"? The flood/waterfall you speak of is what has us concerned, with the 1262 putting out at half flow and one of the bulkheads is blocked the tank will flood.
Your 150 is set up with 4 total drains all going into your sump or are some part of a closed loop?

To all, What size bulkheads/pump combo are everyone else using for reef ready tanks?

 

[billdogg]

All my drains go directly to the sump. I use a reeflow dart as the return - it is split 4 ways - one to a return across the bottom rear - it is drilled with numerous holes to help increase flow behind the rocks. the second return is to a manifold arround the top with 8 locline outputs dirested to randomize the flow at the top. the 3rd return is just over the top in back to increase total flow into the DT. the 4th is plumbed to my 120g refugium with DSB, Cheato, and a bunch of LR rubble for pods.

As for the siphon....... There are many here how will claim that a 1" drain will handle 600gph. Although that is true to a point, that is with it running at the ABSOLUTE maximum, with NO margin for error. Any blockage/restriction will overwhelm it at that point and you will be mopping up the result. Please refer to www.wetwebmedia.com and visit www.glass-holes.com - both will backup my statement that 300gph is the SAFE maximum for a 1" drain

wetwebmedia is also a great reference for all things aquatic - please check them out to help with any other questions as well.

 

[pugmommie]

I was thinking if I took my middle hole that I am using for the closed loop and made that into a return then I would have 3 1 inch returns to sump.

Then I can just route the closed loop over the tank instead of using a bulkhead.

Do you think that would give me the flow I need?

 

[billdogg]

That at least will give you some margin for error, however if it is truly a closed loop, you will be short one hole anyway. A closed loop begins and ends in the tank itself, bypassing the sump completely. You can bring the return for a closed loop over the top (I do), but would still need an intake hole. Hope this helps!