Overflow siphon question

[sruiz]

Just finished plumbing a 75 Gallon with a 40 Gallon breeder. I went with a overflow from modular marine that is a slim/low profile. The overflow is the two piece that is held together with two 1" bulkheads. The outer bigger box has three 1" bulkheads that lead to my sump via separate pipes. All pipes leading to the sump are 1". Because of the size of the outer box I was required to reduce both of the inside durso/elbows to 3/4", and kept the emergency flush at 1". So I fired this puppy up with my return eheim 1262 and I was able to tune the overflow fine with both of the elbows siphoning all the overflow water. The 1st elbow is shorter and fully submerged, the 2nd is slightly higher and is adjusted with a ball valve. This ran fine with no problems but was a little loud because of the large amount of waster passing through my display.

Two days later I installed baffles in my sump for 3 compartments (overflow/skimmer/return) and let the silicone dry. Another change I did was install a T to divert more water back to the overflow section to reduce water into my display. The initial setup ran just fine but it sounded like a high turnaround and thought I could plumb a reactor in the future running off the T.
So back to my problem: My overflow is now running through the emergency 1" pipe. With my initial set up it would run to the emergency overflow for a few seconds then both of the elbows took over. Now however the elbows stay fully submerged and the emergency pipe is doing all the work. Even when I turn off the pump the elbows stay submerged and need to be pulled out for the box to drain the water into the sump.

The changes I noticed since the baffles were installed is the obvious that my water level is higher in the sump (overflow compartment). My drain pipes were about 2-3 inches submerged with no baffles but now they are about 6 inches submerged due to the fact that they are in a smaller compartment.
I also realized that the initial setup usually calls for a air hole/tubing on one of the elbows. I had no problem at first but now I'm thinking this may help.

What can I do to get this overflow working properly again?

Thanks,
Saul

[EvenFurther]

With a 3 pipe drain, run a Bean Animal. 1 tuned full siphon, 1 trickle, 1 normally dry emergency. You don't want 2 siphons.

I had a modular marine box and could fit 1" pipes for a BA drain, no reducers.

[woodnaquanut]

To expand on EvenFurther's post...

Have you read any of the BA posts? That would help you see the correct setup. Full siphon has the only valve. Use it to adjust flow so only a small amount goes into the open channel drain. This is the 'secret' to making it silent.

Back to your issues after the sump has baffles. The siphon drain should be one inch or less below the sump surface when the sump is at normal running depth. This will let it clear out any trapped air and become a full siphon.

[Thakinguvhearts]

Not exactly sure of your plumbing but it sounds like you are running 2 3/4 dursos through 1" bulkheads with a 1" emergency?

First off you shouldn't go smaller with a Durso you should actually go larger by 1/4". So if your reducing to 3/4" it's not going to work very well. Also you shouldn't have a ball valve on a Durso. You control the height by controlling the airflow. 2nd on a herbie or bean animal the ball valve should be on the main drain(lowest pipe).

I'd it was me I would take out those reducers and make all 3 1". I'm not sure on your box size but the main pipe(lowest) would be the one you have the ball valve on. If an elbow doesn't fit than don't put one on. Just make sure it's deep enough. Than the second pipe bring up to where you want your water level I'd say an inch from the teeth. Than make sure the dry pipe is a half inch higher than that to keep it dry.

[sruiz]

Thank you all for your response, I'll make the proper adjustments when I get home tonight.

[Thakinguvhearts]

Oh and you use the ball valve to reduce your full siphon to bring your drain to just slightly slightly less than your return so that a trickle of excess goes into the 2nd tallest pipe which will stabilize the waterheight. Does that help?

[sruiz]

Nailed it guys, thank you all for your feedback. I think my first mistake was to try and make the upside down U shape with two 90 degree elbows. Since I could not fit two 1" shaped U's in my overflow box I went with the reducer to 3/4". To make things worse I was stuck on the upside down U shape and I even reduced it further down by using the 3/4" elbow reducer to 1/2 inch that allowed me to connect another 3/4" elbow on that reduced side.
I guess I can compare that to running a mile then trying to breathe through a straw. Lol

I took your advice and used 1 single 90 degree elbow for both of the overflow pipes. The lowest one is now connected to the ball valve which allowed me to slowly raise my water level to the second elbow that sits a little lower. The emergency pipe was fine just as it was.
I also shortened my overflow pipes that lead into the sump and now they only sit ~1" under the water level. Looks like it's finally running as it should. The water level does not even come close to the emergency pipe.

Big Thank You to All.

[don_chuwish]

Photos?

[rickztahone]

Nailed it guys, thank you all for your feedback. I think my first mistake was to try and make the upside down U shape with two 90 degree elbows. Since I could not fit two 1" shaped U's in my overflow box I went with the reducer to 3/4". To make things worse I was stuck on the upside down U shape and I even reduced it further down by using the 3/4" elbow reducer to 1/2 inch that allowed me to connect another 3/4" elbow on that reduced side.
I guess I can compare that to running a mile then trying to breathe through a straw. Lol

I took your advice and used 1 single 90 degree elbow for both of the overflow pipes. The lowest one is now connected to the ball valve which allowed me to slowly raise my water level to the second elbow that sits a little lower. The emergency pipe was fine just as it was.
I also shortened my overflow pipes that lead into the sump and now they only sit ~1" under the water level. Looks like it's finally running as it should. The water level does not even come close to the emergency pipe.

Big Thank You to All.

You got there in the end :). I like to leave my emergency line out of water because just in case your other two lines fail, you can audibly hear the emergency line splashing water through your sump