PH set for Calcium reactor HELP

[reefislife]

Right these things do my head in:-

I want to switch off a peri pump and switch on a solonoid to stop co2 IF my tank fall below 7.8ph, however I want them to come on again when the PH rises back to 7.9ph

Can someone tell me what to set please.

Minly its the delta min and delta max that does my head in.

Thanks

Craig

[RobbyG]

pH program

Set Ref = 7.9
Delta Max = 0
Delta Min = .1
Plug for Co2 (Up Arrow) = Plug On Symbol
Plug for Co2 (Down Arrow) = Plug OFF Symbol

This assumes that you are not using a Timer to keep on your CO2 at only specific times of the day. If you are using a timer then remove the (Up Arrow = plug on) command.

[reefislife]

thanks, think that makes sense, not on timer at moment but I think it will be, but then if this works I can leave it on 24/7 and not worry about a bad drop in ph.

[RobbyG]

Your Welcome.
BTW just make sure your probe is calibrated ok.
A little trick that I do is to keep all the USED 7.0 fluid from the tiny envelopes in a small plastic Pill Jar. Once every two weeks I dip the probe in some fresh water for a few minutes to kill any algae growth then I dry it and Dip it into the Pill Jar to see how close it is to 7.0* If its off too much I re-calibrate and add the used 7.00 into Pill Jar and then check probe again in Pill Jar. If I now get say 7.05 I mark the Pill Jar Label as 7.05 so in the next two weeks when I test again the probe should read 7.05

I know the Old Calibration fluid is not going to be 100% accurate so I read it after each proper calibration and relabel it so my Biweekly tests I have a fairly good reference.

BTW never clean pH probe with RO/DI water it will ruin it!

[RonBuck]

In refrence to Delta min and delta max.

Delta min: How far below you want your Ref. value to drop before that plug either turns on or off. Say you have 7.9 as your ref. you set Delta min to 0.5, this will turn on or off the plug at 7.4

Delta max: How far above your ref. value you want the unit to turn your plug on or off. If your ref. value is set to 7.9 you set your Delta max to 0.5 then your plug will turn on or off at 8.3.

Hope that is as clear as mud for you. :D