ATO for coral tank stability

[leafy9]

I've been running an ATO on my 75-gallon mixed reef for about six months, but my salinity still fluctuates more than I'd like. It's usually between 1.024 and 1.026, but I'd prefer it tighter. Using a Tunze Osmolator with a 5-gallon reservoir. Anyone else deal with this?

[angler_lee]

Yep, had the same issue with my Tunze. Switched to a dual-sensor setup with a backup float switch. Now it's rock solid at 1.025. Also, check your reservoir size—5 gallons might be too small for a 75-gallon tank if your room's humidity fluctuates a lot.

[foxden9]

Yep, had the same issue with my Tunze. Switched to a dual-sensor setup with a backup float switch. Now it's rock solid at 1.025. Also, check your reservoir size—5 gallons might be too small for a 75-gallon tank if your room's humidity fluctuates a lot.

Seconding the dual-sensor idea. I run a Neptune ATK with two optical sensors and a float as a failsafe. Salinity hasn't budged in months. Also, what salt mix are you using? Some are more prone to swings.

[vortex9]

My ATO's been sketchy too. Using a cheap one from Amazon, and it's all over the place. Gonna upgrade to a Tunze after reading this. How often do you guys calibrate your refractometers?

[angler2]

Calibrate mine weekly with 35ppt solution. Also, make sure your ATO tubing isn't kinked or clogged. Had that happen once, and it messed with my salinity for days.

[nirvo_1]

bruh, if your ATO's acting up, check the pump. Mine was weak sauce and couldn't keep up. Swapped it for a stronger one, and now it's chill.

[finchly]

I don't use an ATO. Just top off manually every morning. Works fine for my 40-gallon.

[leafy9]

Yep, had the same issue with my Tunze. Switched to a dual-sensor setup with a backup float switch. Now it's rock solid at 1.025. Also, check your reservoir size—5 gallons might be too small for a 75-gallon tank if your room's humidity fluctuates a lot.

Seconding the dual-sensor idea. I run a Neptune ATK with two optical sensors and a float as a failsafe. Salinity hasn't budged in months. Also, what salt mix are you using? Some are more prone to swings.

Thanks for the tips. I'm using Red Sea Coral Pro. Maybe I'll try switching to a dual-sensor setup.

[angler_lee]

Red Sea's a solid mix, but it can be a bit finicky with evaporation rates. If you're sticking with the Tunze, maybe just add a second sensor. Cheaper than buying a whole new system.

[foxden9]

Also, keep an eye on your sump's water level. If it's too low or high, it can throw off the ATO's performance. I aim for a consistent 8-inch depth in mine.