[solitude127]

Originally Posted by Member No. 1

Mike just for clarification...
The Litermeter III is touted as a dosing pump that can perform as an ATO vs calling it an ATO per say.
The APEX DOS is basically the same, a dosing pump the can perform as an ATO, AWC, Dosing.
So not to confuse, APEX also sells an ATO that has optical sensors, a safety float valve, pump and FMM (Fluid Monitoring Module). This will work stand alone, or integrate with an Apex controller. The DOS will not work stand alone, you need an Apex to control it.

Thank you for the clarification. I've always loved spectrapure pump and when I heard that they might come out with a continuous duty peristaltic pump for CaRx, I got excited but I don't think anything ever materialized.

Originally Posted by billdogg

I've been at it for 30 years now. I've never used an ATO because I've had too many things fail on me to trust one fully.

FWIW - my 120g DT is SPS dominated slightly mixed reef. IMHO/IME, the few gallons that evaporate over the course of 2-3 days isn't that big of a swing to really harm anything. I do have my topoff water plumbed up to the back of the tank and controlled by a remote switch so that I don't have to schlepp buckets anymore.

If it ain't broke, why fix it.

Originally Posted by reefgeezer

I use food grade liquid level switches, a small 12VDC powered solenoid, and a Brute for my DIY gravity fed ATO. It's bulletproof and has been operating for years without fail. It also keeps the level within about 1/2". All I have to do is fill the Brute every 3-4 weeks.

3 switches are wired in series to control power to a normally closed solenoid: 1) a normal level switch closes when the level drops below the desired sump level and opens when the level returns to normal; 2) a high level cut off opens when the level rises too high; and 3) a low level switch opens when the level falls too low to protect the solenoid from over heating. Finally, a Kent mechanical float valve is installed as a final fail-safe. It will cut-off flow if the sump get just slightly higher than the high level switch level.

The switches are about $12 each, the solenoid is about $20, any little 12 volt power supply will run the thing. You probably have one laying around the house or can buy one a Radio Shack for a few bucks. The load is very small, but make sure all the components are rated accordingly.

Sounds like a viable option. I wish I was more mechanically inclined.