I purchased this little ATO from BRS about a year ago, as they had a great price on it. My first impression was that the quality looked good - nice peristaltic pump unit, float switch, drip counter, wallwart, and spare flexi neoprene tube for dosing pump. Unit is easy to mount, and it was up and running in less than 10 minutes.

After adjusting the float to teh level I wanted to maintain, however, I began to hear a grinding noise coming from the pump. I took the cover off of the unit, and added additional silicone grease to the flexible peristaltic tubing. This quieted it down for a couple of days, but after about a month, this noise became a regular occurrence. Every time the ATO came on, the struggling little pump just didn't have enough get-up-and-go to turn the spindle wheel no matter how much lube the santoprene tubing had on it. So, I adjusted to teh clicking, ratchety noise, and the unit did a good job keeping water level constant.

Then about a month ago, I noticed that the water level had dropped dramatically. I opened te stand and looked at the ATO unit. The spindle was not spinning, but the motor shaft was. I unplugged it, and after manually topping up the tank, examined the spindle. The spindle(roller) unit is made of clear plastic with 2 white plastic wheels at teh ends. It rotates and compresses the tubing, moving liquid along as it does so. The clear plastic had cracked, relieving the frictional bond between the spindle and the roller, rendering the unit useless. I immediately contacted Aquamedic USA for support. This unit comes with a 2 year warranty, but the email I got back from customer support stated that they needed a reciept showing it was pourchased within a year. I sent a copy of my receipt along with a polite note telling them that their warranty states there is a 2-year period. No response. A few days later, I sent another email asking if my receipt had been received. Again nothing. I waited a week and sent another email. I waited ANOTHER week, sent another email. By this time I was getting pretty upset, so I sent a final email to the company suggesting that I would truthfully review their product in every online forum that I belong to, which is quite a few, if I did not receive immediate customer support. Nothing. I then sent an email to Aquamedic europe HQ. Within a week I had my spindle.

Put the new spindle on, greased it up good, and now there is more of a struggle than ever. The unit will struggle for fifteen minutes to pump a few ounces of water. I don't know if the roller wheels are too large on the new spindle they sent or what, but this is getting too much - and I have just noticed a small hairline crack developing in the new spindle assembly! The underpowered pump, and possibly oversized wheel are acting together to render this ATO almost completely useless. I suggest passing this unit by for something more reliable with less liklihood of breakage/noise production/reliability. I hear good things about A-M products, I cannot recommend this one however.

I've got two of them, and they work very well. I had to change the neoprene tubes in a year more or less (if I recall correctly they even come with a spare one). In one of them I've had a broken spindle after two years in service.

Other than that they work very well. The design has an advantage over other ATO like Tunze's Osmolator. It is very slow, very well suited to small tanks. I use an Osmolator for a 24 gallon tank, but for my 6 g nano it would be too much and the Aqua Medic unit is really convenient.

The spindle has indeed a design flaw: the shaft exerts a strong force on the material. However, you can try to strengthen the spindle by tying the central cilinder of it with a couple of very tight cable ties. That will hopefully strengthen it in case a hairline crack develops.

I grease the tubes every 6 months or so. And, remember, it's not so good for large tanks with a lot of evaporation.

At $160 I would expect this to at least work without any problems.

Autotopoff.com. Done.