Dialing in valve+return pump incorrectly?

[shootingstar_reef]

I have a Waterbox 45.2, with a Nyos 3 return pump.

I had so much difficulty adjusting the flow rate when I first set up the tank, and now every time I do a water change to the point I kinda just give up and let it stay at whatever level.

I know this will be hard to believe, but there is probably a <2mm difference in adjusting the drain valve between the water level of the back chamber reaching the brim of the emergency valve, or reaching the bottom of the drain-basket. It is impossible for me to reach anywhere inbetween. The valve physically cant be turned in such small degrees.

I contacted waterbox and they only suggested sending me a new drain valve, which doesn't seem like it helped.

My return pump is on the LOWEST setting, or the return chamber will empty faster than it can be filled. Am I doing something wrong, or does this sound like a normal situation? Did I use the wrong return pump? Should I contact them again? I have no idea what to do

 

[ReefRusty]

I found my drain valve was very sensitive to any adjustments. Hopefully you find that sweet spot it can be very frustrating.

 

[Sailingeric]

is your valve a gate valve or a ball valve? Ball values are a pain and I would recommend a gate valve. Mine took a while to dial in the last little bit

 

[shootingstar_reef]

I believe it's a ball valve, but there is no gate option for my model.

 

[DrufusReef]

I have the waterbox 130.4 and I ran into the same issue. It is very sensitive. I fixed the issue by letting the box fill up to the over flow and slowly opening the gate until the water fell just beneath the main line. Then I added one quart of salt water to the sump at a time until she was quiet as a mouse. Note: wait atleast 15 minutes before each change to let the flow balance out.

 

[DrufusReef]

I have the waterbox 130.4 and I ran into the same issue. It is very sensitive. I fixed the issue by letting the box fill up to the over flow and slowly opening the gate until the water fell just beneath the main line. Then I added one quart of salt water to the sump at a time until she was quiet as a mouse. Note: wait atleast 15 minutes before each change to let the flow balance out.

Once you have it set just mark the water level on your sump with a sharpe or something so you know where it needs to be and where to set your ATO if you have one.