This is a great product for the price. I use it on my 40 breeder QT tank and have had no problems.

I can't believe, I went so long with out one...lol

For the money it is an ok ATO however the floats tend to stick and will mess with your salinity. I had to put both floats in the sump as a safe guard so that if one float fails the other will turn off the ATO. I have had multiple instances were it has nearly overflowed my sump.

The JBJ A.T.O. system is a good, simple auto top system. I have been using it with absolutely no problems. My only complaint is I wish there were more mounting options included with the sensors. I think if you are using a traditional system, you would have no problem. My water storage is a little unique, so I had to modify the sensor bracket.

I love JBJ product. This ATO is well designed and easy to set up. I will order another to use from my freshwater tank.

What this unit really needs is a way to double up on the fill sensors. That way if a snail gives one a ride it would not cause the tank to overfill and ruin your salinity. In other words, the unit would have to recognize when both sensors are calling for top off water to come on.

well constructed, and love the ability to use in many different ways.. I can't believe, I went so long with out one...lol

The JBJ ATO is a very simple design. It has a nice looking control module that nicely mounts to the inside of my tank stand, hidden but still up off anything that might get wet. The only drawback I had was that there was no good way to mount one of the sensors in my RODI reservoir so it kind of just floats around in it.

This is a great ATO switch. The only thing that I don't like is that the ATO checks every ten seconds to see if it is full and then turns off. So on a smaller tank that not turning off for possibly 10 seconds might cause salinity swings.

I installed the JBJ ATO over the weekend, it doesnt come with a pump so I purchased a Toms Aqua lifter pump from my local fish store. The unit works perfectly, I check my water level every morning and the level is always at the line I drew on the side of my sump.

pretty simple idea and thus simple enough to instal. The only complaint I have with this is there arent any instructions in the manual describing the level at which the floats are activated. took me a few minutes to find the "sweet spot".

Other than that this has been a worthy purchase. keeping my SG steady as opposed to dumping a gallon of water everyday is the first step in keeping a healthy reef. Many thanks to JBJ

I like this unit a lot. Makes it easy to use and also a must if you have a sump.

I have had this on one of my tanks with a Toms aqualifter for about 1 year now. Has always worked flawlessly, the aqualifter is a perfect pump for it as its quite,doesnt back siphon, there is no danger of burning it up either. the JBJ controller is easily adjusted for sump level and pump maximum run time.I Would recommend this for anyone looking for a reliable auto top off system

Way cheaper than competition but does not show in its quality. Works great so far and does what it needs to do..top off.

Low cost is nice, but in this case you get what you pay for, & I'd rather pay a little more for an important function.

Went on vacation for a week, thank God I had a tank sitter - he found the sump water level dangerously low 3 days into my vacation, with the return pump spouting tons of bubbles into the display tank. Good thing the return pump didn't run dry - would've fried it. Could've gone the opposite way, with the ATO pump running until it overflowed the sump!

Randomly it'll quit working - pump light is on but pump not engaged, confirmed the pump is fully functional. ATO box has to be powered off & back on, usually it'll reset back to normal the first time it's power-cycled.

This is an update to my review below. Initially was having problems with it automatically timing out randomly when it would turn the aqualifter on. Was leaving for vaction for three weeks and had no time to get a replacement. Worked around it by having the reefkeeper turn it off an reset it every 45 minutes. I've been monitoring it by cam while I'm on vacation. 10 days in, I wake up this morning and log in and one of my water alarms is going off. It has failed now in the on position. Every 45 minutes when the reefkeeper rests it, it's kicking on for the max of 14 before it times out. Can't tell if my floor is flooded yet and had to make an emergency call to a friend that's been checking on the tank to head over and unplug the damn thing. Total junk, thanks JBJ. If you are using this, I highly recommend you don't rely on it to go on vacation.

Easy setup and works great with 1/2 hose and MJ1200. Dont forget to get a pump when buying this. After research I decided not to go with the aqualifter pump due to head pressure and friction loss in tiny tubing.. Get a better pump and this unit and your set.

Another great JBJ product, couldn't be easier than this. Works great, a must have for anyone using a sump.

This ATO does exactly what you expect it to do. JBJ gives you a few options on how you would set it up, and although I am not an expert I think they include every applicable way to work an ATO.

I have one sensor in the third chamber of my sump and the other in a bucket full of fresh RO/DI water. When the water level in the sump gets low, it fills it. If the sensor in the bucket gets triggered it stops pumping water, which saves the pump.

I paired this with a Marineland Maxi-jet 400.

I just got the JBJ ATO and it's doing the same thing others have reported on various forums. Randomly, sometimes as much as once an hour, the controller turns on but with in a few seconds goes into time out mode shutting the pump off. I have it set to the max, which lets it run for about 13 1/2 minutes when it's working the way it's suppose to. Some have said the aqualifter may not be drawing enough power, like the reefkeeper problem with Koralia pumps on the solid state relays. I plugged a lamp in, in addition to the aqualifter with no change. So I'm not blaming the aqualifter at this point. Power draw doesn't seem to be the problem. I believe it's a problem with the electronics of the ATO itself. I found a work around on the internet of putting a timer on the ATO using my reefkeeper. Once an hour the reefkeeper turns the ATO off and back on resetting it. This works fine, but my confidence in the ATO isn't that great since I have to manipulate it to work. If the timeout becomes frequent enough, eventually it won't keep up, and worried it will end up having some other failure. Wishing I would have went with the Tunze now, which I'll probably do, and end up almost $300 into an ATO vs $200 if I had bought the Tunze from the beginning. I love BRS, but looking at the return policy for the first time, it states warranty issues must go through the manufacturer, vs. being able to return a defective product directly to BRS. I'd like to swap it for a Tunze, rather than trying to get it fixed or replaced. So that was a disappointment also. Buy yourself a different ATO.

Don't be fooled by two float switches - they don't work as you'd expect. Instead of redundancy - 1 "high" switch as a backup in case the "low" switch fails or is blocked - it's just 1 switch for minimum water level and 1 switch for maximum water level (Mode B). Or 1 switch in the ATO reservoir to protect the pump from running dry (Mode A). Anyone serious about safe ATO wants redundant switches in the sump/tank. Now I have to decide if I want the Tunze or DIY with my controller.
More minor concerns are the mounting brackets for the float switches. They don't fit over the rim of my tank very well and the height setting is adjustable in only large increments.
The float switch "guards" don't look like they'd keep anything out - any small to medium size snail could get in there and block the float's motion.
All together a disaster waiting to happen.

I've ordered two now, one about a year ago for my main tank and now this for my pico. ATO units don't need to be complicated. They just need to do three things:

-Transfer water from a reservoir to your sump/tank.

-Not overflow your sump/tank.

-Shutoff when reservoir is empty to prevent pump failure.

This product does all three, but does not come with a pump so I'd recommend the aqualifter.

Feels a little cheap but runs like a champ. I've had one for over a year with no hiccups and just ordered another one for a frag tank.

I really regret this buy.....got it for a friend tank....My 2 Tank are on an Osmolator....never had issue....But the JBJ failed to restart after a power outage....no more light nothing !

Had this unit and really liked it at first. It seemed to work fine just as advertised. 6 months in the controller has stopped working and emptied my reserve almost causing a major disaster. I figured this was just a stuck float or something but it was not, unit no longer works. Save your money and buy the bigger dosing pump with a timer or even better allow a controller to do it for you.

Ok, so I wrote a less than glowing review of the JBJ auto-top off. I managed to do a web search and found that you have to take the unit apart to change the setting for the fail safe. Mine was set as low as it could get and my aqualifter just couldn't keep up. Once I took the unit apart and set it for the 14 minute setting, it's worked with no problem. bad design.

This thing does not turn my aqualifter on. It doesn't matter how I have it set up. I've heard that the aqualifter doesn't draw enough power for the JBJ to even pick up on, but I find that hard to believe. I want to use the Aqualifter because I want a slow top off, but, so far it's been worthless. I have to manually push the float switch down for it to pump any water. This is becoming more of a pain than it's worth. I was better off manually adding water every day.

This works great for ATO. It meshes well with the aqualifter

I have had this unit on my 57 gallon tank for 1 month and love it! Easy to set up. However, I wilsh they had a manget option for the sump float switch as the suction cups don't work that well. Long story short, I made my own.

In short, I highly recommend this product. In fact, I am buying a second one right now!!

i got the auto top off about 5 months and it just makes everything so much easier to have a high mantiance hobby

I have had this controller on a few tanks for the last 3 years and it has performed well. Be sure to take the safety time limit (3 min max I believe) into account when selecting the pump. You want to be able to run less than that amount for normal top-offs but less that what would cause a flood.

A very quick to set up and run ATO. Everything is tucked away out of sight in the sump area and the unit comes with more than enough hanging options for the floats. Good product.

This product does exactly what I needed. There's not much else to say. I haven't been using it for long so I can't speak to the longevity and final value, but it was easy to set up and works great so far.

Purchased for my SPS dominated 40 Breeder. Works well out of box, and very easily assembled.

Mounting brackets are a bit of an issue dealing with, but I ended up fabricating my own for my needs.

I got this unit two weeks ago, and it has worked great. No more filling up the tank every day.

As expected a great product at a great price

I wish I didn't wait so long to buy this ATO. This is a great product at a great price. For some reason I thought it came with a pump which it did not; no fault of the product, I should have read the description more thoroughly

I have three reef tanks each needing top offs daily of up to 1.5 gallons. This has relieved me of much daily work. It is accurate and dependable. An inexpensive pump works like a charm, and keeps the specific gravity constant. Two caveats though. Make sure the outflow is above the tank water level to avoid reverse siphoning, and remove snails from the sump. Twice a tank flooded because a snail interfered with the sump sensor.

great item to have install in your tank/sump. removes the daily maintance to top off your tank manually. especally on a small biocube :P

man I like this little item, it keeps my tank topped off , so I don't have to worry about my water levels dropping off to much.

This ATO is great for the money. I used it connected to a MJ 1200 and 5 gal reservoir and never had any issues. Make sure your hose from the reservoir to the tank is out of the water or it will back siphon. Definitely recommend.

I've had many tanks over the years and this is my first ATO and wow I cant imagine ever having another tank without one again. Easy to setup and use well worth the money

I bought this ATO just about 10 months ago so i could go on vacation and it performed perfectly. to this day its still running strong keeping my water at the correct level

This is an amazing product, comes with many different mounting heights and has an auto shut off for when your top off water runs out so that your pump does not stay on and burn itself out.

Note: this does not include a pump so you will need to get one, but buy it and be happy that your tank will have more stability and you wont have to do manual top offs near as much!

We have had one of these systems running our ATO for the last 2 years. With the exception of occasional cleaning of the float switched it works maintenance free. We now have three of them on our three tanks. Great value for a solid ATO system.

i started to use this ato system and i absolutly love it!

I use this with a Tom's Aqua lifter, and a 5 gallon bucket from Home Depot. Works perfectly except when I mess with things like adjusting the skimmer. Safety timer turns it off even though it isn't done filling. Haven't had any problems besides that. Have usually caught it when it happens.

should come with a on off switch for water changes