Drains under water decreasing flow?

[kylecanada]

I have (2) 1.5" bulkheads with CJ standpipes for my drains to the sump. The drain lines have a ball valve at the bulkhead and flex pvc down to the sump. Both flex ends are under the water level in sump. Will the ends of the drains being under water decrease my maximum flowrate. I have a Dart that is probably pushing under 2000 gph and my drains are unable to keep up. Within 20 or 30 seconds the water wants to overflow the display. I thought 1.5" bulkheads would be more than sufficient. I do have 90 degree elbows at the bulkheads to turn down into the sump. I am scratching my head trying to find a solution. Any suggestions would be appreciated.

[kylecanada]

Anyone?

[LobsterOfJustice]

It's possible. Sometimes air is trapped in the pipes and because the output is under water the air cant escape, which can cause problems with water flow.

[ReefEnabler]

LobsterofJustice is right.

I was having gurgling issues with a similar setup. I installed some "vents" on the drain where it enters the sump.

My drain pipe is a horizontal run to the sump, and then it does a T, with one end of the T going downward, and a short section of pipe extends down into the water.

the top of the T then has an equally tall section going up, and a cap on top of it. I drilled two 3/16" holes and stuck in some 1/4" airline tubing. Due to the natural curve of the airline tube, they kind of do a 180 and point down at the sump. You might want to double check the drill bit size against the tubing you use, but for me it was a tight sealed fit.

I used two lines so that there is one for each durso (each durso has a hole about that large, so I know thats about how much I need to vent).

The air coming out from each of these tubes is enough to blow out a match. They occasionally drip water, which is fine because mine hang right over the sump.

If I use my finger to plug the 'vents', the amount of turbulence and gurgling in the sump increases significantly. This is because without venting, the pipe will need to build some pressure in order to push air bubbles out, and this could definitely mess with the flow capacity.

[Spedward]

Got any pics of that Ryan?

[ReefEnabler]

I have a somewhat outdated pic. unfortuantely this one doesn't show the airline tubing, but it shows how my drain is a T:



basically right above the image there is a cap on the PVC. then 2 airline tubes come out and curve forward, almost like antennae.

I also use a filter sock on the drain (not pictured). This reduced my bubbles and turbulence in the sump more than anything.


If I could do everything over, I would do herbie style drains

you can see how the drain is attached to a union, which goes into the crawlscpace. that union is shaved down pretty slim to fit, lol.

[Spedward]

Cool... thanx.

so you have both drains feeding your horiz line which terminates at the tee, and two vents in the one cap....

what size pipe is that?

like your wiring conduit fitting...lol

[ReefEnabler]

I have two 1 1/2" dursos that meet at a Y at 2", and the 2" pipe runs 25" horizontally to the sump with 3" of vertical slope. Right now it's handling ~1200gph. Was very hard to do the bucket test in a cramped space so I can't be too sure of the flow.

ya just made use of an extra street ell on that "conduit" its just some telephone wires for my controller to communicate with the display tank. my high voltage wires are all run through proper conduit.