AutoAQUA Automatic Water Top Up Aquarium Fish Tank

A good quality top up unit a bit pricey but having used for 3 months I know it’s reliable.It also has a memory for topping up so you can be sure it won’t overfill your aquarium as it cuts out once the memory has maxed out and you have to reset

Superb piece of kit, easy set up & very accurate.Tank has never been so stable, would reccommend product to anyone!

Working perfectly so far with kalkwasser mixed in top off water. Make sure initial top off is short to guarantee good redundancy, as pump and alarm will go off if 3 times initial top off is exceeded

Very good product.

Let's start by saying set up is so easy, a caveman could actually do it.I installed this micro ATO on a 3.7 Gallon Imagitarium mixed reef tank for work. Having three day weekends made keeping a stable salinity difficult due to water evap even with a cover. This removed that worry. It keeps the tank a static salinity/SG. The water reservoir is under my desk in a five gallon bucket.I don't run Kalk in this set up but do use RO/DI. Hoping this lasts a long time. This was easier to set up than my tunze 3155. The water tube line holder for the tank/sump is not much to be desired. My Tunze one is better and does a better job preventing a back siphon. I shouldn't have to worry as there is an inch of space between the tube and water surface in the back chamber. The sensor is low profile, has a blue light (red or flashing when water low). This would certainly be useful in any size tank.Since I've only had it on a week and half or so I have given it five stars since it does its job. In the event it fails, I will adjust this review.***UPDATE***After a year of use, still going strong with no issues. I will be getting a second soon as I am setting up my 20g long predator tank.

Once you have your Ro/di container in place and know where you are going to put the sensor and hose it literally takes seconds to install and setup.You just drop the pump in the Ro/di bucket, place the sensor a little above the water level with the included magnet, place the output hose so it pumps the water to where it should go, and plug the cords in. Done! It does the rest. It will beep and flash. Then start filling and stop once it reaches the sensor. It remembers how long it took to do this first fill up and if it ever runs a little longer it beeps and then stops pumping shortly after. This let's you know it had to pump more water than normal. Great for saltwater tanks, helps stop accidentally pumping all you RO water into your sump and ruining the salinity.Great unit! Mines been running non stop for 3 months no problems.

EDIT: 12/31/19 - Changing this to a 1 star because the pump or sensor malfunctioned dumping 4 gallons of water on my hardware floor. I'm reaching out to Coralvue for support. Everything has worked perfectly for 6 months. I only unplugged the power to refill my ATO jug. I plugged it back in and it started to fill and I walked away. I returned 15min later to a flood living room. I verified the issue multiple times and the pump and or sensor refuses to shut off.For what an ATO is, they are all overpriced. It does work great and helps keep my tank topped off when I'm to busy to check on it.One thing I dislike about it is the check valve piece that keeps it from reverse siphoning. It drips way to much water so I have to keep a towel around the tube so it doesnt get all over the floor. Easy fix with a ball valve or something. Just keep that in mind.Other than that it has been great. I used a 7 gallon camping water jog behind the tank and it catches those drips. So far it's been a blessing.

I've used the Hydor Smart Level and the IM ATO in past. It's not even close out of the box this is the best. First it includes everthing you need including the pump. Second the small size is ideal especially if you are trying to get a handle on and manage space to reduce clutter. Micro relates I think to the size of unit not it's application. While I use it in a Nuvo 16 I see no reason it would not work in a much larger set up. Positives besides size and completeness is it is very quiet compared to competition. It does beep and flash but compared to others the beeping and flashing does not continue on and on even after it has started or completed its work. Also the db level of beeping seems less to me. Another big positive is it maintains water level much better so salinity stays more constant. Learning curve is way less on this unit than any other I have used.Negatives. There are none right out of the box. However if the pump fails you will likely have to replace the entire ATO unit. Some have stated the pump does not have sufficient power. All I can say is in my previous set-up I used a Tom's Aqua lifter and this pump works better. I have had no problem lifting water as far as the wires will allow. Magnets could be stronger, but I have not had problem per se. The blue light on the sensor is a lttle bright for my tastes if you were to keep the tank in your room and like darkness when trying to sleep.Tips: I would not use the siphon break that comes with it. It's just a place for it to leak. Just make sure the water tube is above the electronic sensor level. While the unit maintains a good water level if you have an All in One tank, the water level in the sump typically drops over time as the fitlers start to clog which will result in a slight drop in salinity. Just be aware and adjust the sensor to compensate if necessary.

Everything but the anti-siphon valve works great. The anti-siphon valve is cheap and very little thought was put into its use in the overall setup. My first setup resulted in siphoning display water into the freshwater jug and then on to my carpet. I disconnected everything and purchased a 3/8s inch check valve separately but the little pump isn't strong enough to open the check valve. I had to come up with new plan. I was then bought acrylic, built a separate freshwater container and placed it side by side to the display tank to reduce amount of water in the line.... Still water siphoned out of display into new container. So frustrating. After about 6 weeks of trial and error, ordering additional supplies I finally have a working ATO. You CANNOT leave the end of supply line in water. I have about a 1/2 gap that allows air only to be siphoned back when pump shuts off. It is sad that such a well built eye and pump lacks the technical thought required for a complete system. Plan accordingly!