It does take a little tweaking to get the air pump timing right, so it doesn't run unnecessarily, so good idea to get it dialed in before you take off on vacation for more than a few days. Mine runs a few minutes almost every hour to maintain positive pressure in the carboy. The timer has 20 programs IIRC, so there are a couple hours where it doesn't run. The blank hours are during the night due to lower evaporation rate. Timings are a bit longer during the day due to higher evaporation rate. Since the air pump is fairly low pressure, there's little danger in it overpressurizing anything. Worst case if it runs too long is wasted electricity and wear/tear on the pump. Once you get it dialed in efficiently, there's rarely need to make further adjustments. I had to fabricate the bracket for my float valve out of scrap acrylic & used nylon screws/nuts to fasten things in place. It's a good idea to have an air check valve in the line between the air pump & the top off container. This helps maintain pressure & prevent leakage back through the air pump. These check valves are only a couple of $$ and readily available at most any LFS.

Smart ATO
 

I just bought one a couple of weeks ago. Love it! The optical system seems to work flawlessly, and has an audible alarm. I like the fact that it doesn't have any float switches and wires in the sump. The pump is small and quiet (I can never tell when it's running). In fact the whole thing is very compact.

I guess time will tell if it's trouble-free over the long run. So far it's great!

I've used JBJ and autotopoff.com and have been happy with both. I have seen Tunze and RO/DI float valve systems fail too often to want to go either of those routes.

I have been running the Hydor Smart level for about 3 months and have not had any issues whatsoever, and it only cost $80 + pump. Highly recommend this unit.

The Smart ATO with the optical sensors also looks quite promising especially if space is an issue.

I was also thinking about the hydor ato or this laser one on fish street

http://www.fish-street.com/triple_se...ategory_id=139

What u guys think will be more reliable

jbj ato for almost 5 years now same ato second pump(my fault on the first pump dosed kalk with the ato and never cleaned the pump for 4 yrs lol) cheap to replace a pump and straight plug and play.

Can I +2 this? :) Same here, works great.

If I send ro straight to my sump via a float doesn't this mean the rodi will continuously generate waste water?

Only when it's actively topping up. No different that manually filling an ATO unit.

a very generous member on here just gave me the jbj for free but its missing float switches. Can i use these from jl on them or can i order a better one somewhere? http://www.jlaquatics.com/phpstore/s...ct_ID=da-zfsk1

also can i just use a aqualifter with the jbj?