Milwaukee pH controller

[copper1974]

I'm a little confused with this controller. I want to plug in my CO2 solenoid on my calcium reactor to the controller and set it to shut off the CO2 when the pH gets too low, say 7.8. How do I set the alarm dial to be "on" above 7.8 but "off" below. How does it know which side of the alarm level to be on or off?

[Ereefic]

I have the SMS-122 and the alarm is backwards, don't know why. When the controller is on (allowing Co2 to flow threw, above your set point) the alarm light flashes. If the pH drops below your set point, it shuts off the delivery of Co2 and the alarm stops flashing. HTH

[AZDesertRat]

The easiest way to use it is to drip your reactor effluent into a container which then overflows into your sump. I use a Lees specimen container hanging on one of my baffles and suspended the pH probe into the container. It is backwards from what you want but works well. Reactor pH is normally run somewhere between 6.7 and 7.0 or whatever works for you so when the pH in the container gets up to 7.0 the solenoid comes on and feeds CO2. When it gets down to 6.7 it shuts off. You have to play with the drip rates and settings at first but I have not touched mine in 2 months now.

[copper1974]

so when the alarm is on, the CO2 should run right? I'll play with it tonight. I was gonna do it about the same way as you mentioned, just have my probe in the tank instead. The bubble rate is already matched with the flow rate to keep the effluent pH at about 6.7 when running.

[AZDesertRat]

Yes,
The alarm light flashes when the solenoid is on. Kinda backwards but it works. Milwaukee makes a reverse version of the 122 that you can get from Custon Aquatic or you can send yours back to Milwaukee and they modify it. I talked with their Tech support people and they are real quick to answer but I decided not to do the conversion.

[copper1974]

no biggie, as long as I know how it works. SO you think I can set the alarm to run above like 7.8 and shut off below that? Or should I set it more for like 8, so it only runs during the day when the pH is the highest?

[AZDesertRat]

I'm not sure although mine tracks pretty true. It is set to maintain about 6.7 or 6.8 in the reactor. I dip the probe in the main tank occasionally just to make sure the tank pH isn't too low and it seems to be fine like that.

[copper1974]

what pH swing do you see in your tank throughout the day then?

[AZDesertRat]

It stays 8.1 to 8.2 24hrs a day. I wish it was more like 8.3 though.

[copper1974]

Mine dips down to 7.8 at night, I am trying to get mroe gas exchange and also put my reactor effluent into the skimmer to try and bleed off excess CO2, I also put lime in my topoff water, hopefully all combined I'll start to see a little more stabilization.