I need help with a bean animal style overflow system not staying at a constant level in the overflow.

[Morpheosz]

It could possibly be that theses variable flow dc pumps are inconsistent with their output.
I was just about to type that as i finished reading your post.
Personally i never had a bean animal drain, i ran a herbie drain for years with a ac pump and a ATO , never an issue.

I'm also hypothesizing that based on my high head pressure relative to relatively low flow rate that any fluctuation in output from the pump could be exaggerated in water height.

With that said it seems consistently high or low. It will drop an inch over the course of minutes sometimes (I sit by this tank all day in my office hence the reason it drives me extra mad), I'll go bump the pump up one or two percent, and it will quiet down and go back up an inch in a matter of a minute or so, then a few hours later it will be heavily flowing over the drain making that noise and I have to go bump it back down a percent or two and again it's fine.

 

[NickSc]

If you a pvc extension on the main drain, remove it to give more distance between the main drain and the emergency. I probable have at least a six inch difference on my Herbie set up.

 

[Morpheosz]

If you a pvc extension on the main drain, remove it to give more distance between the main drain and the emergency. I probable have at least a six inch difference on my Herbie set up.

That would be fine if I was OK with the water level dropping more than an inch or so in the overflow, but I'm not because when it's lower than 1-2" it starts splashing down from the weir and making a lot of noise and salt spray.

 

[NickSc]

You can try using bio foam to eliminate the splash or you could raise the merge by drain if you have room. The bean animal is overkill, you only need on main drain and one emergency.

 

[Balthazar]

I had about 3 inches of height difference in the overflow between the main and emergency drain if that's what your saying. I did that to quiet down the water cascading noise into the overflow. With my ac pump i pretty much set the gate valve and forget it.

 

[Balthazar]

I'm also hypothesizing that based on my high head pressure relative to relatively low flow rate that any fluctuation in output from the pump could be exaggerated in water height.

With that said it seems consistently high or low. It will drop an inch over the course of minutes sometimes (I sit by this tank all day in my office hence the reason it drives me extra mad), I'll go bump the pump up one or two percent, and it will quiet down and go back up an inch in a matter of a minute or so, then a few hours later it will be heavily flowing over the drain making that noise and I have to go bump it back down a percent or two and again it's fine.

Personally i would try another return pump and a ac one at that if you have one on hand, its an easy swap out to see if the dc pump is the issue.

 

[CollectOyster04]

I think the problem is adjusting the pump for the overflow height. You should be adjusting the gate valve to the sump to account for the pump instead. Every time you're adjusting your pump, you need to adjust the gate valve. Open or close the valve(slowly) until you get the desired height. Once your pump is at the desired flow rate, leave it alone. Just my two cents.

 

[Morpheosz]

I think the problem is adjusting the pump for the overflow height. You should be adjusting the gate valve to the sump to account for the pump instead. Every time you're adjusting your pump, you need to adjust the gate valve. Open or close the valve(slowly) until you get the desired height. Once your pump is at the desired flow rate, leave it alone. Just my two cents.

I've tried both. I put a flow meter on the return as well and it is consistent so it's almost certainly the pump that is changing output.

 

[Morpheosz]

I solved this over the weekend by pulling out my secondary drain, cutting it down, and adding a pair of 90's to make it a U shape similar to the primary drain. To that I added a hole and airline tube to prevent siphon (inspired by many pics on the internet). Now it can run with a trickle without me hearing it. I've run for 2 days now in blissful silence!

 

[Lonestar77566]

I had the same problem. The constant drop and rise in the overflow was driving me crazy. It turns out that my partial drain was set too high. I cut the stand pipe and lowered it to about an inch above my main drain and about 2" lower than my emergency drain. So far, the level is maintaining.