Overflow not siphoning properly. I’m lost.

[lpsouth1978]

(Cracks knuckles...let’s do this)

If your drain is pushing out bubbles, it isn’t siphoning and most likely your secondary drain is handling the bulk of the flow. Since it has a hole on top for the airline tube, it’s able to pull air into the drain, hence the “hottub” effect. How I remedy this and put the flow where it should be is to remove the durso altogether from the primary drain. It’s unnecessary. The problem with running durso on the primary full-siphon is that the water level in the dry-side of the overflow box needs to be high enough to create a pressure differential that’s great enough to force the trapped air bubbles in the tube out of the bottom and into the sump. By removing that durso, you lower the necessary water level to get the siphon started efficiently. That’ll fix most of your problem. Tuning should be a matter of closing the primary drain’s ball valve until the water level in the dry-side overflow very slowly creeps up to where the secondary drain starts functioning. Technically, you don’t even need a ball valve for the secondary drain, but I use one and ever-so-slightly close it just to reduce noise more than anything.

your main drain the one with the two 90 on top is supposed to be under water bout half way down the overflow with a gate valve on it.
second pipe sou;ld have two 90s on it at the level you want water in overflow, i suggest up near the top because water going into overflow makes noise in itself.
doesnt look like you have another hole for a emergency drain.
you adjust gate valve to where bubbles stop coming out main drain or you can tweak it a bit allowing some bubbles but not enough to make much noise and the other pipe will automatically set the level in you overflow and handle the rest of the flow.
i have 2500 gallons a hour going thru mine and its whisper quiet.

this would work great IF he had a secondary drain. However, he only has a single, durso, drain.

 

[Crustaceon]

this would work great IF he had a secondary drain. However, he only has a single, durso, drain.

I see it now. That’s a single drain and return line in the corner overflow. Yeah, a siphon ain’t gonna work in that. A durso is really the only option.

 

[Seanb1]

what are these two pipes?
is one a return ?
if so another option could be to just run a return up the back of the tank and over the rim of tank, make both holes in overflow drain pipes.
lockline kits are cheap on amazon.

 

[ca1ore]

Looks like a marineland tank? 1” durso is ‘rated’ to 700 but just doesn’t handle much more than 500 gph well. You get noise, that flushing effect and lots of mess in the sump. Either convert to a herbie-style drain or back the pump to 500 gph.

 

[Michael Rossi]

I currently have that exact tank and that exact problem. My return isn’t adjustable though.

 

[nereefpat]

I currently have that exact tank and that exact problem. My return isn’t adjustable though.

It is if you put a ball valve (or better yet, a gate valve) on the pressure side of the pump.

 

[Michael Rossi]

It is if you put a ball valve (or better yet, a gate valve) on the pressure side of the pump.

Would something like this work for flex tube?

 

[lefkonj]

Sorry if someone already suggested this but take a bunch of RODI water and pour it down the small clear tube sticking out of the drain. Same thing happened to me it can backup with salt build up and prevent the system from working correctly. Once I cleared this I was able to run my pumps at 100% instead of 30%.

 

[Michael Rossi]

Sorry if someone already suggested this but take a bunch of RODI water and pour it down the small clear tube sticking out of the drain. Same thing happened to me it can backup with salt build up and prevent the system from working correctly. Once I cleared this I was able to run my pumps at 100% instead of 30%.

Awesome tip. Unfortunately it didn’t work for me though lol. I think I’m eventually going to get a larger sump so I’m hesitant to hard plum it right now. Although that would still be cheaper than buying another pump.

 

[lefkonj]

Do you have a valve on the drain line. You can dial it in to get to become a siphon, I have that on my marine land 180. I also have the drain lines well under the water level in the drain section of my sump. Just a few ideas before going crazy.

 

[nereefpat]

Would something like this work for flex tube?

Yes

 

[Michael Rossi]

Do you have a valve on the drain line. You can dial it in to get to become a siphon, I have that on my marine land 180. I also have the drain lines well under the water level in the drain section of my sump. Just a few ideas before going crazy.

No valve on the drain either. I have the Esohopps RS-100 sump which has its own chamber for the drain with a long drain under the water line. The more I thought of it last night, I think i'm just going to hard plumb it and add a gate to the return. even if i change the sump down the line, I'd just need to potentially re-plumb it, which at the end of the day is a pretty cheap option.

 

[nereefpat]

FYI, do NOT valve down the drain to make a siphon if you do not have an extra emergency drain. You will flood your house if the siphon gets clogged.

 

[lefkonj]

FYI, do NOT valve down the drain to make a siphon if you do not have an extra emergency drain. You will flood your house if the siphon gets clogged.

Agreed you don't want to put a valve on a single drain system. I always put valves on all my plumbing so it is easier to do maintenance on.