Herbie drain system

[NanCrab]

I can’t get behind the tank for a picture but if you look at this one on the left side overflow I have the main drain with the gate valve and a return with a siphon break. On the right side I have a return without siphon break and the emergency drain. We have high and low levels marked and a Tunze ATO.
It will be humming right along and so quiet you can’t hear a thing then, for no apparent reason the main drain will start making horrible loud gurgling noises like it’s trying to quickly drain the tank and then the ATO comes on. But normalizing the level doesn’t always work. My husband gets annoyed and starts messing with the gate valve and ATO which may help for the moment but doesn’t solve the problem.
Is this just normal with a Herbie? Honestly even if the tank didn’t have to cycle i think it’s a good idea to run it without livestock just to get all these kinks worked out.

 

[Steve Burton]

Which drain is the noise coming from? You want to main drain to be closed enough to have a full siphon (be full of water with no air sucking through) which is achieved with just a trickle going through the back-up drain.

 

[lmm1967]

I don't believe you will ever solve that problem in your current setup.

With 2 non-connected drain compartments - EACH compartment needs a tunable full siphon plus an emergency.

Run your returns up and over the top of the tank and set up the 2 overflows the same way - each with a tunable full siphon plus 1 emergency / partial siphon

 

[NanCrab]

I see now that autocorrect got me again. Too late to edit post but it’s supposed to be Herbie

 

[jcook54]

I see now that autocorrect got me again. Too late to edit post but it’s supposed to be Herbie

Fixed it.

 

[NanCrab]

Thank you!!!!

 

[kullas]

Is the ato in the overflow or in the sump?

 

[NanCrab]

QUOTE="kullas, post: 1235306, member: 229"]
Is the ato in the overflow or in the sump?
[/QUOTE]
In the sump. I’ve unplugged it for now, will top off manually as needed. Perhaps my tank and plumbing are too new and fluctuating.

 

[phishfoodie]

I don’t believe you can have a “main drain” under full siphon and an “emergency” drain herbie style setup in 2 different overflow boxes. You essentially have it setup as one drain that will full siphon and then cause a constant flushing situation.

Best to do what suggested above and run external return lines and then use the 2 lines in each individual overflow as herbie style drains or keep your returns as they are and add 2 Durso style drains which are not as quiet as herbie.

 

[sharis100]

I think people are suggesting either 1. one Durso style drain per side so one in each overflow along with one return per overflow side , 2. or alternatively one Herbie drain on one side and both returns out of other side in other overflow, or 3. third way is a separate full Herbie setup in each overflow and run the returns on the outside back of tank up and over the tank. Marine Depot has some good drawing explaining each drain style and pros and cons for each style setup.
The posters are suggesting that the toilet flushing sound cannot be totally stopped with your current configuration and recommend these solutions to keep it quieter.

 

[sharis100]

addendum: no one mentioned but there are stockman standpipes instead of Durso or Maggie Mufflers to quiet drains - both of which have been around a while.