Aquarium Marine Reef Fish Tank Automatic Auto Top Off Water Filler Water Level Controller Smart Top Up ATO System (ATO)

I was a little skeptical about this purchase due to some of the odd feeling review on this ATO. I have been using it for over 2 weeks and has worked perfectly. The main unit feels very well built. The small pump works great but not the same quality as the name unit, it feels a little cheap. The tube holder that goes on the tank/sump is a little big and too long and too large wherr the tube goes into it. I had to it bent funny to keep it from falling out. The tube holder needs a simple redesign and it would be a perfect unit. The lens that goes on the inside of the tank may be an issue getting clogged with junk if not in a high flow zone. System seems like it has a dry protection. I had a lot of bubbles in the line and the system freaked out like it was empty, but the instructions are not the greatest. Highly recommend this product great price and works flawlessly.

great inexpensive auto top off solution.Only thing its missing is an audible alarm if the unit disconnects from the back of tank.The cord pulled the unit off the back one week and I didnt catch it until my tank started sucking air in the back. At least I know now that a disconnect doesn't activate the pump!

I throughly love this product, very nicely designed and a lot smaller than intended, however this is a PLUS because it allows people, myself included, to attach this optical eye sensor directly to the tank. Being that this unit is small and compact it is great for nano setups, bought mine for my fluval evo 13.5. Also pump is low watt and very quiet and efficient which all in all makes this a beautiful design, kudos to this company for providing a wonderful product at such a GREAT price point!Buy this and you won’t regret your purchase!Update!! Months later this thing is as good as new and better than ever if something happens to it I’ll be upset, but instantly order a new one, GREAT PRODUCT!!

This product never worked for me. I have a few tanks and utilize an automatic top off on multiple of them. The controller does nothing but beep as though the pump is bad but I’ve used different, known good, pumps to no avail. I initially reached out on Amazon indicating I might have a bad pump (my first thought) but never received an answer or reply of any kind.

I've run this and after a year, I bought another. Keeps my SPS tank super stable, works great on AIOs. I say this because I noticed that if external light hits the sensor, things like overflows may occur, My advice, place the sensor in low light and keep the wetside clean and algae free. if you get a beep outta knowhere, just take the pump apart, rinse in ro and re-assemble. Super easy to maintain. I havent used with Kalkwasser so I'll be updating after using with kalk.

I have had this for a little while now. It works alright but if the ATO sensor is even a little bit off it will over fill the sump I have it in. I have come back to it 3-5 inches above where I have it set too(it’s a 30 gallon sump so I’m sure it’s a couple of gallons more than it should be…)Other than that is works great just hope it doesn’t over fill and then we lose power or else water is gonna be everywhere… especially since it’s a 150 gallon tank!

[Update]My replacement failed - it's only been a year or so. Which really stinks.[Original]I've had this ATO running for several years - where it's run flawlessly. My last water change I noticed it looked "wrong". I pulled the magnetic optical part from in the tank and it had expanded and ruptured causing the iron core to be exposed and rust. Luckily I had used a lot of charcoal in the previous water change and I caught the problem early so there appears to be no ill affects on my coral.I ordered a replacement, but just needed to magnetic optical ring to get it running again. I'd give it 5 stars if it hadn't ruptured but since I replaced it with the same thing and will probably get several more years out of it, I gave it 3 stars.Just keep an eye on the magnetic part inside your tank.

I read a lot of reviews about this and all those ones I gave it a negative I have to disagree this thing works awesome. the warning beeper only times when the refill tank out of water other than that I don't have to pay attention to it thank you