I screw up with overflow design. Please need help to fix

[CoralB]

Try opening the valve all the way open and shake the hose to release air bubbles then after bubbles are gone re adjust the shut off valve

 

[mare021]

Try opening the valve all the way open and shake the hose to release air bubbles then after bubbles are gone re adjust the shut off valve

I'll try. Thank you.

 

[Crustaceon]

The elephant in the room is the over 1" piping on a 40 gallon tank. It's going to be nearly impossible to displace the air in the drain to eliminate noise and not push so much return pump flow into the display that the overflow box can't handle it and the tank will either overflow or the return pump chamber will empty. How you fix this is by running 1/2" on your primary siphon drain, a 3/4” on your secondary and a 1” emergency drain. This is going to be overkill as-is because you’ll probably be pushing less than 500gph to the display with the return pump. The goal was keeping air out of the lines. Having ginormous drains makes this impossible. You have no need to handle 3000gph return pump flow and as a result, you’re getting noise. I ran the exact 1/2 - 3/4 - 1 setup I recommended on a 100g with around 450gph return pump flow. It worked flawlessly and I never got anywhere needing the emergency drain and could easily empty the overflow box if I fully opened the gate valve on the 1/2” siphon. It was dead-silent when tuned. 1/2” -> 3/4” -> 1”. No doubt, no question, your problem is the size of the drains. They are WAY too big.

 

[theMeat]

Try opening the valve all the way open and shake the hose to release air bubbles then after bubbles are gone re adjust the shut off valve

This is what I was thinking. ^
You don’t want to open it open enough, or for long enough, that you start to suck air down primary…
The other thing I’d do is change that flex hose to a rigid pipe without glue so you could remove it if you want

 

[CoralB]

I use the herbie design which only has two return pipes with one lower that has the shut off valve which I adjust the level in the overflow to where the the water is just trickle over on the higher second drain tube

 

[CoralB]

This is what I was thinking. ^
You don’t want to open it open enough, or for long enough, that you start to suck air down primary…
The other thing I’d do is change that flex hose to a rigid pipe without glue so you could remove it if you want

Yah!! I just thought about that after you mentioned it and you might be correct on using straight tubing as the flex is probably trapping air because in order to use the roller mat which I don’t , wouldn’t that tube have to be out of the water or are they totally submerged?? Which intern would cause constant noise defeating the purpose of having the drain setup that he has ?

 

[mare021]

I'll try. Thank you.

I tried but no result. Air is still traped in pipe.

 

[vetteguy53081]

Flex line is part of the issue as well as the strainer- try an elbow in lieu of strainer

 

[BZOFIQ]

Your valve needs to be as close as possible to the outlet, closer to the water. There is just too much air in that line that cannot be purged or may just take too long to purge.

Move it down, open it fully at start then dial it in to maintain a full siphon

 

[mare021]

Flex line is part of the issue as well as the strainer- try an elbow in lieu of strainer

I'll try. Thank you.

 

[mare021]

Your valve needs to be as close as possible to the outlet, closer to the water. There is just too much air in that line that cannot be purged or may just take too long to purge.

Move it down, open it fully at start then dial it in to maintain a full siphon

It's not feasible in my case. There's lack of space because of Rollermat

 

[mare021]

Hi. I replaced soft tubing with smaller diameter 32mm pvc pipe after gate valve. It's much better, not total noiseless but acceptable. Thank you all for your help.