Sump return pump section water level

[X-37B]

My Red Sea XXL 750 return goes haywire once in a while .... basically every once in a while the ATO water coming in to the top of the tank (can't have it go into the sump or else it would cause a siphon) the water doesn't come down fast enough causing the ATO to keep pumping.... it's a 200g tank and i've had 7 or 8g pump in and water level rise to very high ... i then have to open up the valve a lot to get the water down.... this is extremely frustrating - big swing in salinity + some other params ....

Yea I have an rs 170. First thing I did was replace the ato with a Tunze. No issues.
I also put a ball valve on the return and run the, horrible imo, gate valve wide open. No issues.
I was going to replace the gate but the ball valve allows Me 100% control without having to replace it.

 

[Johnd651]

That seems like a LOT. My 20g Long goes through MAYBE 1 quart in 24 hours

Not really. Super dry hw radiator heat, open top, rimless, with skimmer. About double of what you are evaporating.

 

[Reeferbadness]

Yea I have an rs 170. First thing I did was replace the ato with a Tunze. No issues.
I also put a ball valve on the return and run the, horrible imo, gate valve wide open. No issues.
I was going to replace the gate but the ball valve allows Me 100% control without having to replace it.

Thanks for sharing! I will see what i can do .... ball valve is a good idea. I do like the RS ATO though - had a Tunz before but really like seeing what's being used via the app - helps me monitor things when i'm traveling.

 

[IIDRYWATERII]

Now working perfectly gone from 5ish litres a day with a peak of 11 to 0 for todays top up…

Reef mat dropped from 3-3.5 to 1-1.5cm giving a more constant water level.