Fluctuating level in my overflow Box

Lovefish77 · Feb 5, 2022

HI everyone,
So i have a 30 gallon waterbox in my bedroom (with a 10 gallon sump). The tank has been quite as a mouse since i set it up. However, the last 2 days i am not able to get much sleep as the water level would drop in the overflow box and then it would started sucking air and make a noise. More details:
- The overflow external box is a herbie with a main drain and an emergency drain. I always set the main for full siphon and the water just trickles over the emergency. This causes it to be super quite.
- Return pump is the syncra sicce 2.0. It has been recently cleaned with no issues.
- Nothing has changed in the plumbing or the tank set up at all, so no idea what is going on.

My doubt is that the low level in the overflow box is possibly due to a weak return pump, my guess is that a stronger pump could possible fill the overflow more? But the pump and the set up has been the same and were working very fine before, NOTHING has changed!!

Any ideas please? I would like to be able to sleep well again

thanks for reading
Have a good one

T-J · Feb 5, 2022

Sounds like the overflow can handle more water than the return can provide.
I know you cleaned the pump, but did you check the return lines to make sure nothing is clogging them?
That's all I can think of.

Projects with Sam · Feb 6, 2022

Check your weir. Could the slats be clogged? It could also be that you need to add more water to the tank.

Lovefish77 · Feb 17, 2022

Projects with Sam said:
Check your weir. Could the slats be clogged? It could also be that you need to add more water to the tank.

I clean the weir regularly. Dont think it is the water the pump seems to get weaker and weaker even thought it was cleaned recently. I had to adjust/close the main drain to raise the water level in the overflow. Very strange!!!

nereefpat · Feb 17, 2022

Lovefish77 said:
I clean the weir regularly. Dont think it is the water the pump seems to get weaker and weaker even thought it was cleaned recently. I had to adjust/close the main drain to raise the water level in the overflow. Very strange!!!

I have to adjust mine every once in a while. Just make small adjustments to the gate valve.