Tunze auto top off question

[Animal-Chin]

I just pit one on my tanks, my question is how do water changes work? I guess i have to turn the ato off but do i have to refill the tank to the exact level it was at before i syphoned out the water? Id its a bit low or high does this mess up the ato?

[Meklo]

I have the tunze osmolator. I shut it off for water changes. It always kicks on and pumps ro water when turned back on. I don't think it's avoidable. I just know where my tank's water running level is in relation to the optical sensor. I can give more info if needed. Sorry if I am not clear enough.

[Dary421]

As meklo stated ,.. Yes you turn it off while doing you pwc ,..then refill the tank ( sump) to that exact level before your water change ,..(most of us prob just have a line drawn on their sump indicating this ),...if you do not refill to this level( under fill ) then the ATO thinks that your tanks water has evaporated and will continue pumping in new water until it reaches the optical sensor which will shut it off,..... The problem here is that in a saltwater tank your salinity will change and will become diluted ,decreasing your salinity....if you overfill your tank and cover up your optical sensor while doing your pwc then your water will have to evaporate until it gets down to the optical sensor before it'll start to work properly,..that will cause your tanks water to increase in salinity.
I've been using them for a few years now and they work very well . , don't forget to adjust your other sensor for the high water mark also,.,very important too ( I found out the hard way ) .
I have found that the best part of the Tunze ATO is that they're electronic and the worst part of them is that they're electronic ,.. Lol,..( and pricey.)

[Animal-Chin]

Ah ha, see this is what I thought. I'm gett the sharpie out and drawing a line on the sump so I can refill to the same hight. That might be tough though cause when I turn my sump pump off it back fills into the sump, how will I know? I guess I'll just make sure that when I take 5 gallons out i replace 5 gallons exactly.

[Dary421]

Originally Posted by Animal-Chin

Ah ha, see this is what I thought. I'm gett the sharpie out and drawing a line on the sump so I can refill to the same hight. That might be tough though cause when I turn my sump pump off it back fills into the sump, how will I know? I guess I'll just make sure that when I take 5 gallons out i replace 5 gallons exactly.

Just mark your line on the sump at your normal operating level with tank running normally,....Mark your high line at the level that flows back into the sump when your power is off and adjust your sensors to those lines.... You might have to tweak it a bit but that'll get you in the ball park.

[Animal-Chin]

Well for a guy with a funny hat you're pretty smart Dary...

[Gregcoyote]

That's his thinking (drinking?) cap.