ATO setup for stable salinity

[guppyfin]

I've been struggling to keep my salinity stable with my current ATO setup. It's a 75-gallon mixed reef with a Tunze Osmolator, but I'm seeing swings from 1.025 to 1.027. Anyone got tips to dial it in better?

[chubsy]

What's your reservoir size? I've found that larger reservoirs (at least 5 gallons) help buffer against rapid swings. Also, check your ATO sensor placement—too close to flow can cause false triggers.

[frostlyn]

I had the same issue until I switched to a dual-sensor ATO. The redundancy cuts down on errors. Also, topping off with pre-mixed saltwater instead of RO helps if your evaporation rate's high.

[MarketStar]

I had the same issue until I switched to a dual-sensor ATO. The redundancy cuts down on errors. Also, topping off with pre-mixed saltwater instead of RO helps if your evaporation rate's high.

Yep, dual sensors are clutch. I run a 10-gallon reservoir with a float switch and optical sensor, zero issues for 8 months now.

[hazela]

How often are you calibrating your refractometer? I've seen folks chase salinity ghosts only to find their tool was off. Use a 35ppt solution to verify.

[beastbyte]

My ATO's basic—just a float valve in a 3-gallon jug. Salinity stays at 1.026. Maybe your Tunze's overcomplicating things?

[Pulse]

I'd check for leaks or kinks in your ATO line. Had a tiny drip once that threw everything outta whack. Also, what's your room temp? Big swings can mess with evaporation rates.

[guppyfin]

Thanks for the suggestions, everyone. Gonna test my refractometer first, then look into a bigger reservoir. Appreciate the help!

[chubsy]

Thanks for the suggestions, everyone. Gonna test my refractometer first, then look into a bigger reservoir. Appreciate the help!

Smart move. Let us know how it goes. Oh, and keep your reservoir covered—dust can gunk up sensors over time.

[MarketStar]

One last thing—if you're dosing anything, make sure it's not near the ATO intake. Stray Kalk paste nearly bricked my sensor once. Sketchy stuff.