Auto Top Off Water Filler Aquarium Mini ATO System Fish Tortoise Tank Water Level Controller No Wiring Float Valve

This is a great product and does exactly what it's supposed to do with minimum trouble and effort IF you use the right water bottle with it. After having it leak badly the first time I tried to install it, I discovered that most bottle of water have channels in the threads that the caps screw on to. I don't know why that is, but the bottle caps use thick plastic seals in the caps to seal them and the o-ring on this device doesn't seal well enough to keep them from leaking. After searching the comments here, I found someone who said that Evian bottles worked for them, so I bought one and lo and behold it works fine, because they've got regular threads that are complete all around and don't have those channels (see the pic for what I mean by the channels).

This product saved the tank in my office. The AC is off on the weekends and the water was evaporating too much before I could get back to refill it on Mondays, and the water parameters were swinging too much. With this guy, I set it up in a about 3 minutes and now every Friday I fill this up and pop it on top of the tank, and the water level stays constant all weekend no problem. One other nice feature of this is you can choose the size/style of the bottle you want to use, to better fit your situation. I just use a small .5 liter bottle and it works great for weekends, but if I am going away on vacation I can use a 2L bottle and things will be fine for longer. Great product!

This thing works awesome with an Evian water bottle. So many people on here writing a bad review because they can’t follow directions and use the bottle it is made for. Other people writing bad reviews cause they can’t afford a rimless tank. This clearly shows it’s not for rimmed tanks. One guy said that it’s not meant for people with fancy rimless tanks because they can afford fancy ATO systems. Not a single picture shows it on a rimmed tank. This thing is great, it’s a great value for a simple easy ATO

Terrible - there's no way to attach this to a traditional tank. This ONLY works for rimless tanks without a frame on them. (i.e. only fancy tanks). People with fancy tanks have fancy ATO solutions...this completely misses the demographic for who would need it (i.e. those of us who have the cheap tanks with the black plastic frame rims). None of the adapters that were sent work on a normal fish tank. Come on.

It's functional and can control the water level. The thing you need to notice is the tube comes with the product is not very long(around 8inch). If you use it to control the turtle tank's water level(like my case), you need to find the way to extend the tube. And need to seal the joint perfectly.

I couldn't be happier with this product!I bought this to maintain my water level while I was away on vacation for a week.In the winter my small (5 gal) aquarium evaporates off water very quickly, and if the water level falls too much my heater and pump turn off - which is no good for a tropical aquarium.After finally locating the Evian water bottles it requires, (I had to buy a case, which cost almost as much as this product) I assembled the filler, (which was very simple) stuck it on my aquarium, crossed my fingers, and left for vacation! I half worried all the water would drain out, overflow my tank and ruin everything while I was away, but when I returned, the water level was right where it needed to be and there was no indication of any spillage. It had used the entire bottle in that time.The only limitation to this product in my opinion is the capacity, since you are limited to the size of the bottles you can locate, but for me, 1 liter was enough for 1 weeks time.I would highly recommend this product for an effective, inexpensive top-off device.

I have two water tanks, a 55 gallon and a 29. I wasn’t able to use this w either as the rim of both tanks is too thick for the thing to even attach to my tanks. My tanks are very average and have that black lip/rim that goes all around. If your tank has one as well you won’t be able to use this product so don’t waste your money. My boyfriend thankfully has a 3D printer and is working on fudging it to fit mine.

I bought this to use as an ATO for a Fluval EVO 13.5 saltwater setup. I didn't want to spend a ton of money on an electronic ATO for this little tank and didn't have the space in my office for one. This was cheap and simple so figured was worth a shot. I've had it on the tank topping off the 3rd chamber (return chamber) of the tank for 2 weeks. It has kept the water level constant and I have not seen any variation in salinity (checking using refractometer). The constant water level has also made the PS2 protein skimmer run more consistently without having to fiddle with the micro adjustments any more as well.