I hate ATOs, please tell me which ones you like and why -

BanjoBandito · May 26, 2022

I can't seem to find a "trust worthy" ATO. I'm currently running a reefbreeders that's not the prism, it's the magnet with the eye piece, and it's constantly missing the mark. My system is big enough that I usually catch it pretty quick. I'm running an apex but their ATO seems like waaaay too many pieces. I want something simple. I also have an old Tunze ozmolater laying around, but I think it's the nano version, it's also caked in kalkwasser (don't ask). So I guess I'm in the market for a new ATO. I've never found one that makes me warm and fuzzy.

TheDragonsReef · May 26, 2022

The regular tunze is the best imo. Its pricey but mine has been nothing but reliable and with 3 safety features its the least likely to overfill the tank.

Eagle_Steve · May 26, 2022

I make my own ATOs.

I use 2 float switches, wired in a series, one up and one down in a diy acrylic bracket and then run those to a small dc pump. I do not have to push water up very high, so have been using cheap cat water bowl pumps to do the water movement. These pumps also connect to rodi tubing without issue. If I have more height to push against, I buy a mj900 or something, a small relay and then use that in a project box to use low dc voltage to kick the relay on and supply 120 power to the pump. The most voltage that could possibly go into the tank is 12v on that one and 5v on the smaller setup.

I have one on my 180 that is over 6 years old now and works like a charm. Using 2 floats also give you a back up one float sticks or something. The setup also raises water only an inch higher is the lower float fails.

Most of them cost me around 15-25 bucks to make. If you have to start from scratch, think around 40, as you will need heatshrink, solder and some liquid electrical tape.

Edit, I forgot you can add a thermal breaker to create a "timer" if you wanted, I have never had the need for it, as 2 floats seems to work perfect for stopping any issues.

flashsmith · May 26, 2022

I used the reefbreeders eye type on my frag setup. It never turned on when it was supposed to. Just took that tank down. I have 2 IM hydrofill systems and never an issue with those but my absolute do without is my red sea gravity feed which works with a manual float in the sump. Love that thing, No maintenance.

BanjoBandito · May 26, 2022

Eagle_Steve said:
I make my own ATOs.

I use 2 float switches, wired in a series, one up and one down in a diy acrylic bracket and then run those to a small dc pump. I do not have to push water up very high, so have been using cheap cat water bowl pumps to do the water movement. These pumps also connect to rodi tubing without issue. If I have more height to push against, I buy a mj900 or something, a small relay and then use that in a project box to use low dc voltage to kick the relay on and supply 120 power to the pump. The most voltage that could possibly go into the tank is 12v on that one and 5v on the smaller setup.

I have one on my 180 that is over 6 years old now and works like a charm. Using 2 floats also give you a back up one float sticks or something. The setup also raises water only an inch higher is the lower float fails.

Most of them cost me around 15-25 bucks to make. If you have to start from scratch, think around 40, as you will need heatshrink, solder and some liquid electrical tape.

I may message you about this later...need to explore.

Tuan’s Reef · May 26, 2022

Tunze 3155. has optical sensor and float switch. this is the go to ATO

SPS2020 · May 26, 2022

I have two different ato's on two tanks. Litermeter on one, expensive, but it works without fail. On the other, I have a Kamoer X1 Pro dosing pump configured to top off pretty much the exact amount each day. For safety, I have an optical sensor on the Apex which will turn off the X1 if the water level reaches a certain point. This configuration works exceptionally well. If\when the water level drops a little too much, I just do a manual water addition via the X1 mobile app.

SlugSnorter · May 26, 2022

I have a bottle attached to a 5$ piece of plastic and two little plastic tubes. It works because science.

Dbichler · May 26, 2022

Avast with peristaltic pump zero issues going on three years one optical sensor and float for back up neither have had issues keeps water level within 1/4” in my sump

Pkunk35 · May 26, 2022

I have had the tunze nano and the xp aqua duetto and I like them both.

tunze nano is nice because it can adjust the flow rate. I hate the 10s required dump of water each time the pump turns on and I kinda hate how bulky this dang thing is in my sump. I also don’t find the additional sensor for overflow that useful bc of its intense bulk. (I have a small sump)

I like the duetto for basically the reasons I don’t like the tunze: it’s tiny, it is super sensitive to the eye sensor both for needing fill and overfilling (the pump starts and stops immediately), there is no bulk and setup takes 5 minutes no joke. Bad part is I do not know if you can use a different pump with this ato so not sure if it can be used for really large tanks. Really love this ATO tho.

hope it helps!

jp_75 · May 26, 2022

Tunze worked ok for one year and than constantly overfilling… Garbage! i clean it every 5 months….

underwaterjr · May 26, 2022

I agree with Eagle_Steve. I’ve used this kit in the past for several years with no problems. I ran it from a ten gallon tank with a mj400 as the pump. Ran flawless.

s1oliver · May 26, 2022

I use the XP Aqua Duetto on both of my tanks and have never had any issues with water levels in 2 years of use.

MichaelP · May 26, 2022

I’ve used the JBj for 10+ years and it’s worked great had to replace a couple of floats but other then that no issues and very reliable

doubleshot00 · May 26, 2022

I use a wifi switch setup to run for one minute at 10am and one minute to run at 6pm. Got the pump from amazon and a shut off valve regulated to keep the flow down. Im gonna try this for a few months then if that doesn’t work ill get a tunze 3155.

Gtinnel · May 26, 2022

Eagle_Steve said:
I make my own ATOs.

I use 2 float switches, wired in a series, one up and one down in a diy acrylic bracket and then run those to a small dc pump. I do not have to push water up very high, so have been using cheap cat water bowl pumps to do the water movement. These pumps also connect to rodi tubing without issue. If I have more height to push against, I buy a mj900 or something, a small relay and then use that in a project box to use low dc voltage to kick the relay on and supply 120 power to the pump. The most voltage that could possibly go into the tank is 12v on that one and 5v on the smaller setup.

I have one on my 180 that is over 6 years old now and works like a charm. Using 2 floats also give you a back up one float sticks or something. The setup also raises water only an inch higher is the lower float fails.

Most of them cost me around 15-25 bucks to make. If you have to start from scratch, think around 40, as you will need heatshrink, solder and some liquid electrical tape.

Edit, I forgot you can add a thermal breaker to create a "timer" if you wanted, I have never had the need for it, as 2 floats seems to work perfect for stopping any issues.

I do about the same including the cat water bowl pump, but instead of just using relays mine is also controlled with a micro controller in the project box. Mine has been running for 3 years with no issues at all.

MONTANTK · May 26, 2022

Eheim makes one. I think it’s called the tsunami. It’s basically a plastic tube with a hose that runs back to a barometer that is triggered when the water is below the tube. I have personally ran 4 of them and worked at a store that used them exclusively and never witnessed one fail

Eagle_Steve · May 26, 2022

Gtinnel said:
I do about the same including the cat water bowl pump, but instead of just using relays mine is also controlled with a micro controller in the project box. Mine has been running for 3 years with no issues at all.

I thought about doing that, but like to keep it simple with just 2 floats. Makes for a single 5v plug, the 2 floats and the pump. Project box is only used if I have to go higher than 3', as a larger pump is needed and I have to go to 110-120v then.

On my 180, it is plugged into my Apex, so when doing AWC, it doesn't top off lol. I guess I could set it up on a timer based on wattage or something, but then that is no longer a simple setup lol.

Pntbll687 · May 26, 2022

I have 2 xp duettos that have worked great for 2+ years now.

But my favorite is the gravity fed ato on my frag system. I literally never worry about it. Even if the float valve were to stick open, all the water would be contained in the sump, the worst would be the skimmer might overflow and have low salinity.