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

  • Based on 125 reviews
Condition: New
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Eligible for Return, Refund or Replacement within 30 days of receipt

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Availability: In Stock.
Fulfilled by Amazon

Arrives Monday, Nov 25
Order within 14 hours and 36 minutes
Available payment plans shown during checkout

Brand: EPTTECH


Target Species: Fish


Special Feature: Lightweight


Style: Modern


Color: Black


Included Components: power,water pump


UPC:


Manufacturer: EPTTECHNOLOGY


Manufacturer: ‎EPTTECHNOLOGY


Part Number: ‎ATO


Item Weight: ‎14.8 ounces


Package Dimensions: ‎7.2 x 5.6 x 2.7 inches


Is Discontinued By Manufacturer: ‎No


Color: ‎Black


Style: ‎Modern


Power Source: ‎Battery Powered


Item Package Quantity: ‎1


Special Features: ‎Lightweight


Included Components: ‎power,water pump


Batteries Included?: ‎No


Batteries Required?: ‎No


Date First Available: July 7, 2018


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Nov 25

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • A few quirks , but great value and no issues
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. ... show more
Reviewed in the United States on February 22, 2022 by Nate Peters

  • Great product for the price will buy again.
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. ... show more
Reviewed in the United States on June 12, 2018 by Braden Braden

  • Works great, could use more features.
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! ... show more
Reviewed in the United States on May 14, 2018 by The Z Family

  • Great product
great product easy to install
Reviewed in the United States on March 1, 2023 by Jvthib

  • Never worked
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. ... show more
Reviewed in the United States on May 27, 2021 by Amazon Customer

  • NO MORE PARAM FLUXES... (Makes this a must have)
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!! ... show more
Reviewed in the United States on August 30, 2019 by Carter

  • Randomly overfills…
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! ... show more
Reviewed in the United States on September 17, 2021 by Austen

  • Split open exposing the iron core in my 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. ... show more
Reviewed in the United States on December 29, 2018 by Keith Rule Keith Rule

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