Best ATO for Pico Tank

[AstroCoral]

I’ve finally had it with my current optical sensor ATO. It decided to recalibrate itself a few minutes ago and filled itself all the way up to the high water level sensor instead of its normal low water level sensor. This just dropped my salinity from 35.2 PPT to 34.5 PPT in a matter of minutes… tank is 3 gallons so every drop of freshwater has a big impact on the salinity. I need something reliable that will not attempt to calibrate to the high level sensor as this is causing instability in my Pico tank. I have an apex but their ato float switch is much too large for my tank so my current ATO is just a basic two level optical sensor.

 

[AScientificReefer]

the tunze osmolator 3155 is amazing I have never looked back, easy to get replacement parts and even use a separate pump if needed
It has redundancies for keeping things stable and functioning as they should

 

[AstroCoral]

the tunze osmolator 3155 is amazing I have never looked back, easy to get replacement parts and even use a separate pump if needed
It has redundancies for keeping things stable and functioning as they should

I’ll look into the tunze, is it pretty accurate in not letting the water level get too high or low? I can’t have more than a cm or two of water level variation.

 

[dmmitchell]

You can go a little cheaper than the 3155 and get the 3152. Similar availability of replacement parts, super reliable. I run them on all three of my nano tanks.

They are fairly sensitive to level fluctuations. I don’t think you’d have any trouble.

 

[AstroCoral]

You can go a little cheaper than the 3155 and get the 3152. Similar availability of replacement parts, super reliable. I run them on all three of my nano tanks.

They are fairly sensitive to level fluctuations. I don’t think you’d have any trouble.

I’ll look into this tunze as well, thank you for the help!

 

[AScientificReefer]

I’ll look into the tunze, is it pretty accurate in not letting the water level get too high or low? I can’t have more than a cm or two of water level variation.

In my experience its accurate, it uses a float switch that shuts off system should the water get above the desired limit as a failsafe. But other than that it does well to keep the water level in check

 

[trapphd]

I’m partial to the (super low-tech but foolproof) gravity ATOs available on Amazon for ~$10. The length of the tubing is at your discretion and it should never deviate when filling the tank. I have it on my 20G and honestly love the simplicity.

 

[curt]

auto top off.com float switchs work great. Been using the same one for over 10 years now with no problems.
This is from there web site
How Sensitive is the switch?
About 1/8" change in water level will trigger the switch. A double switch controller with the custom latching option will allow you to set how much water level change will trigger the controller.

 

[Northern Flicker]

I’m partial to the (super low-tech but foolproof) gravity ATOs available on Amazon for ~$10. The length of the tubing is at your discretion and it should never deviate when filling the tank. I have it on my 20G and honestly love the simplicity.

I agree with this for pico tanks. Perfect solution.

 

[Blue Spot Octopus]

Gravity ATO
Something like this,

Clscea Aquarium Auto Top Off​

From Amazon
I use them on my nano's they have never failed me.

 

[Spicy Reef]

The best "ATO" i've come up with for my 5g reef bowl is a tight fitting plexiglass lid.

 

[AstroCoral]

I’m partial to the (super low-tech but foolproof) gravity ATOs available on Amazon for ~$10. The length of the tubing is at your discretion and it should never deviate when filling the tank. I have it on my 20G and honestly love the simplicity.

I’ll have to look into these, I’m starting to get tight on my budgeted cash for this tank so this may be the best option in my case. My current ATO would work well in an AIO where the water level differs more substantially but filling another couple centimeters to an inch in my 3 gallon system is not working out so well. My coral didn’t seem to react to it much but it certainly isn’t good for these swings in salinity to continually occur.

 

[Aquaddictorbj4]

I recommend XPAqua Duetto2, with dual optical sensor and the controller is small and compact.
Using over 1 year and still performs perfect.

Duetto2 Dual-Sensor Complete Aquarium ATO System

Tiny, Reliable and Long-lasting Auto Top Off System *NEW Controller programming & circuitry for added system protection *NEW Improved sensor design for longer durability World’s smallest dual-sensor ATO Two layers overfill protection Intelligent QST programming Secondary optical sensor Super...

www.bulkreefsupply.com

 

[muffinmanXL]

I recommend XPAqua Duetto2, with dual optical sensor and the controller is small and compact.
Using over 1 year and still performs perfect.

Duetto2 Dual-Sensor Complete Aquarium ATO System

Tiny, Reliable and Long-lasting Auto Top Off System *NEW Controller programming & circuitry for added system protection *NEW Improved sensor design for longer durability World’s smallest dual-sensor ATO Two layers overfill protection Intelligent QST programming Secondary optical sensor Super...

www.bulkreefsupply.com

This likely won’t work for a 3 gal Pico - it is not sensitive/precise enough and dispenses too much water - I struggled with the Duetto overfilling my 5gal project

 

[afrokobe]

I recommend something like this or creating a small over flow area where the water level is bit more sensitive.

 

[Narideth]

I’m partial to the (super low-tech but foolproof) gravity ATOs available on Amazon for ~$10. The length of the tubing is at your discretion and it should never deviate when filling the tank. I have it on my 20G and honestly love the simplicity.

I also use the gravity fed ATO for my 13 gallon, and I just bought another and the tiny bottles to fit into a tighter space for the 3 gallon pico I'm building. Works great, keeps things topped off for 2-3 days with just a 1 liter bottle.

 

[csturgis1989]

For a Pico tank I wouldn’t go with a Tunze 3155 since it will definitely add too much water for a 3 3 gallon system. The 3155 pump can be adjusted lower but every time the power is reconnected to the system the pump turns on for a systems check. I would recommend the Tunze 3152 for your application since the pump flow can be adjusted lower and the pump won’t turn on when you plug it in.

 

[Rockit]

I got one of these for temporary use on a QT tank about 5 years ago. Put it on my 20 about 4 years ago when I was going to be gone for two weeks and couldn't top it off every AM like I always had. It has been a rock solid performer and absolutely flawless. Level doesn't fluctuate at all as far as I can tell. It comes on for 1-5 seconds dozens of times a day... a few cc's each time.
Only 2 complaint is there's a green indicator light when it is pumping. Tank is in the bedroom and the LED is unnecessarily bright. Problem solved with duct tape.