Noisy Overflow & Sump Fluctuation Issues

[Arrow1oo]

So I’ve been working on getting my 300 gallon tank up and running (8’ long x 2’ wide x 29” high). The plan is to house SA Cichlids so I knew I needed good filtration.

My tank has an internal overflow in the middle behind a weir and has 4 bottom drilled holes:

2 3/4” returns on the outsides
2 1” drains in the middle

Naturally, I set this up with a herbie and for the most part everything works well.

I have two jebao dcp-6500 pumps and I am using a 75 gallon tank loaded with poret foam as a sump.

While the sump works fine, I’ve been having a hard time consistently tuning it.

I’ve been keeping the pumps at 60% and I tuned my gate valve on my main drain to match that flow rate, but every time I come back the next day the water line behind the weir is either a bit too high or a bit too low and causing some noise.

Additionally, when I go to adjust my gate valve I can hear slight gurgling which tells me something might be off.

I’ve been through this process a few times but no matter what I always end needing to make adjustments which seems wrong.

Through the research I’ve done, the only potential solution I’ve found is threat evaporation in my sump effects my pumps return rate every so slightly. But I’m not sure.

If that is the issue, I can always add and ATO.

Would love some help on this.

 

[M3AN ONE]

Herbies are hard to tune so that they are dead silent. My suggestion would be to run both returns at full tilt and the drain pictured on the left leave it completely opened up since it has the elbow that will be below the water level it will be silent. On right drain slightly open it just enough were you can control the water level of the over flow chamber. Only issue is if a drain is clogged there is nothing you can do. I have 3 drains the last one is a backup thats is above the water level so if one clogs it will kick in. When that one is running it makes a loud sound as the water gets sucked in.

 

[Arrow1oo]

Appreciate the help but I’d be scared to leave my system susceptible to flooding if there’s a clog.

I’ve seen multiple people on YouTube achieve a herbie setup that can reestablish a siphon and run pretty quiet.

I’m pretty sure I’m doing something wrong but for the life of me I can’t figure out what it is.

Currently my emergency standpipe is cut flat, I’m wondering if I angle the cut maybe it would help me allow a trickle to go down the emergency easier.

I also am considering lowing my main standpipe a bit more, currently it’s 6.5” below my emergency but I’m wondering if that causes the siphon to suck in air too easily

 

[LBDave]

Evaporation or stuff like food caught in the main drain line can change flow rates. For me I just try to keep the sump as full as possible when I do water changes. I also adjust so that water line inside the intake box is just below or level with the overflow.
A little water going down the overflow is much quieter than having the level too low.
When I adjust the gate valve I do it in very small increments.
Lately I have had to adjust more than usual (and add water) because the weather has been hot (evaporation).
Also. the main drain needs to be at least 6" below the overflow. 7-8" preferred. This keeps bubbles/ air from entering the main drain.
(I have a herbie setup with the weir only at the top).

 

[Arrow1oo]

Evaporation or stuff like food caught in the main drain line can change flow rates. For me I just try to keep the sump as full as possible when I do water changes. I also adjust so that water line inside the intake box is just below or level with the overflow.
A little water going down the overflow is much quieter than having the level too low.
When I adjust the gate valve I do it in very small increments.
Lately I have had to adjust more than usual (and add water) because the weather has been hot (evaporation).
Also. the main drain needs to be at least 6" below the overflow. 7-8" preferred. This keeps bubbles/ air from entering the main drain.
(I have a herbie setup with the weir only at the top).

Got it, I believe evaporation might be the culprit honestly.

Because the footprint is so long (8’ long x 2’ wide), it loses quite a lot.

I think I’ll add an ATO to help fight this. I’ll also double check to make sure the main standpipe is low enough although that doesn’t seem to be the issue.