Apex control of Co2 regulator by PH

[fuxing1985]

Hi folks, I am trying to find a way to control my CO2 regulator by PH. I would like to tell Apex to turn on the CO2 regulator when the PH is higher than 6.5 and shut it off when the PH is lower than 6.4. Basically, I do not want to keep the PH at a certain value, but instead in a range between 6.4 and 6.5. I have problem finding the correct code. I tried the following.
1. Set Off
2. If PH > 6.5 then On
3. If PH < 6.4 then Off
The problem with this is that once PH drops to below 6.5, the CO2 regulator will be turned off. The Ph will always be 6.5 +/- 0.01

1. Set On
2. If PH < 6.4 then Off
3. If PH > 6.5 then On
This one basically has the same effect as the first one. Once the PH is below 6.4, the CO2 regulator will be turned off. The Ph will always be 6.4 +/- 0.01

Does anyone has a way to maintain the ph in a range instead at an exact value? In this way, we can avoid frequent on and off cycle of the apex outlet and CO2 regulator solenoid.

Many thanks.

 

[william Lutman]

Following

 

[sfmacguy]

this is how i have mine set.

 

[fuxing1985]

this is how i have mine set.

Thanks. This is similar to my code. I think with your code, the CO2 regulator will be activated once the pH rises above 6.80. The pH will never reach 6.75.

 

[sfmacguy]

It definitely does. As soon as c02 is input into the reactor the PH drops. The solenoid then turns off until it reaches 6.8 again. Here’s a graph of ph2 (reactor probe) over a day in use.

 

[rossco]

Set using fusion: but I have my bubble count so close to being exact that the solenoid only is turned off twice a day.

 

[Sisterlimonpot]

Remove the "set on" or "set off" statement. Then it will operate in that range. It also a good idea to have a "fallback off" statement just in case the eb loses connection with the apex.

 

[fuxing1985]

Thanks a lot. It worked after removing the "set on/off" statement.

 

[lakai]

 

[brick-brothers]

Set using fusion: but I have my bubble count so close to being exact that the solenoid only is turned off twice a day.

I'm curious to why you have your range high. Is your daily alk or cal consumption low?

 

[rossco]

I'm curious to why you have your range high. Is your daily alk or cal consumption low?

Giant calcium reactor (Geo 818) and a 210 gallon tank full of frags and mini colonies that is just 8 months out of a restart after losing 90 percent of my huge acro colonies after a crash.

 

[brick-brothers]

Giant calcium reactor (Geo 818) and a 210 gallon tank full of frags and mini colonies that is just 8 months out of a restart after losing 90 percent of my huge acro colonies after a crash.

Ok gotcha