This is only partly true. The other part depends on the distance of the sensors. The Reef Breeders ATO sensors are much further apart than other ATO sensors. I have one in my Evo and the water drops almost 2 inches in the return prior to the pump kicking on. When I ran a Duetto, the level in the return chamber dropped about a half inch if that.
yes all of them are like that. The 3155 has been around for years. The osmolator 3 is the new one. I have both currently. The 3 has changed the design up from the 3155 a lot. Sometimes with the 3155 you have to make sure the sensor is clean or it may not operate, I just clean it when I do maintenance I used to keep a power head in the return chamber which also seemed to help. So far the 3 I have been using since January 0 issues it just works.
I’m looking at the osmolator nano being that my tank is 32.
Thats the one I have not used. As far as I know it works just like the 3155. 3155s are on sale right now still I believe making room for the 3. I have the 3155 on my 30g. No sump just hob filter.
There are a bunch of reviews of the Duetto 2 failing on and flooding a system. This can probably be said about a lot of ATO's to be honest, since people tend to complain when things fail and fail to praise when things go great. But, the big thing with the Tunze is the 5 year warranty... No having to replace failing pumps due to the constant on/off of the pump for at least 5 years... gotta love that.
I have issues not many and usually related to cleaning the sensor. Other than that Tunze just work. I have never used a different brand so I have nothing to compare, but the way some of these sound like they are set up is just dumb. Why would you want that much evap before it turns on? As soon as thewater moves away from the sensor on a Tunze the ato kicks on, as soon as it touches the sensor it shuts off. Why would you want anything else?
I have no clue why they chose the sensor distances they did for a lof of the ATO's. I had the ReefBreeders Prism, twice, and it worked, had a slightly larger salinity swing than I would have liked because the sensors were so far apart (and the tank it started in didn't have a well-sealed AIO compartment), but it worked solidly for 3-4 years, then it failed, and I figured for less than $100 why not get a new one? Well, that one failed after only 4-5 months, tops, so I just got the Tunze Osmolator 3. It's fantastic, but as you said, cleaning the sensor is a must. I never had to clean the sensor on the prism, I've had to clean the sensor on the Osmolator three once already and I've had it about 3-4, maybe 5 months.
I haven't touched the 3 yet been using it since january. My 3155s I cleaned/clean weekly typically if I didnt/dont it will act up a couple days later. But I keep an eye on the return chamber regardless. My 3155 is on a sumpless 30g so its even more important to keep it clean.
