NOISY overflow - please help

[Muse]

I'm having a total nightmare with this new tank. It's a Boyu tank and overflow, it has 4 pipes to the sump:

1. Drain valve (for water changes)
2. Return to tank from sump pump
3. Emergency overflow
4. Main drain to sump

When I start the return pump if I fiddle with the main drain pipe valve I can get the diaplay tank water level between the drain and emergency overflow, but the pipes still causing a vortex and sucking air like crazy, I can't stand noise on tanks...

Thanks

 

[Saltyreef]

I cant see your main drain that well.
Is there even a pipe connected to it? Or is it free draining down the bulkhead assembly?

 

[theMeat]

What you have is essentially a herbie style . The second drain is not an emergency, and the main drain designed to be full siphon.
Watch a vid on how to adjust herbie style drain

 

[Scubatricky]

https://blog.marinedepot.com/education-center/charts-diagrams/durso-herbie-bean-animal-overflow this should help

 

[Saltyreef]

What you have is essentially a herbie style . The second drain is not an emergency, and the main drain designed to be full siphon.
Watch a vid on how to adjust herbie style drain

This is correct.

I mistook that drain valve section for a 3rd drain :)

 

[Muse]

I'm totally confused sorry! So pipe 4 should be fully siphoned using the valve on it? And water should also come down pipe 1 (water change pipe I referred to?) thanks for commenting guys

 

[theMeat]

I'm totally confused sorry! So pipe 4 should be fully siphoned using the valve on it? And water should also come down pipe 1 (water change pipe I referred to?) thanks for commenting guys

Drain valve should be off/closed unless you’re draining tank for water change or whatever.
The drain with valve gets closed until the other drain (that says overflow outlet in your pic) is taking in water about halfway, an elbow on top of this (secondary) pipe helps
The water from overflow box should be a half inch lower than tank water, and the height of the secondary determines this. As long as the primary/full siphon drain with valve is a couple of inches and not sucking in air it will be quiet.
It takes a minute or three to purge air from full siphon , then it will be steady and strong, adjust from there

 

[Greg P]

If the other suggestions don't work, try removing the standpipe on the main drain. This will most likely eliminate any sucking/gurgling noise with a full siphon.

 

[Muse]

Thanks guys! The problem with this setup is the overflow can take in tank water from vents at the sand level in the bottom of the tank! What a stupid design?? Therefore the display tank and weir will always be the same level! (see photo)

I've tweaked the valve but the watere ventually reaches the emergency drain after a few minutes or if I open it a little bit too much it starts chugging air in a whirlpool... No sweet spot.. I don't know what to do.

 

[theMeat]

It doesn’t matter if the box has a hole in the bottom to set the height with valve to allow it to run halfway down the secondary, which is not the “emergency” on your herbie style plumbing.

 

[theMeat]

https://salttankreport.com/herbie-style-overflow-guide/

 

[Muse]

I just wanted to thank everyone who took time to comment on my post. I see a lot of forum questions answered with no response from the OP.

Thanks I've now solved the problem

I slightly extended the emergency drain to allow a greater tolerance to play with. The main line is now in full siphon with hardly any noise. I think my outflow pipe joins are allowing air to seep inwards. This will be easily fixed with silicone applied externally.


Thanks again