Anyway to use the 24 Avg value for pH doser control?

[TCoach]

I am trying to follow Chris Meckley’s (ACI Aquaculture) method of dosing kalkwasser for pH stability. Part of that is using the 24 hour average pH to slowly increase the pH to the value you want to maintain. Is there anyway to set the nominal value of the pH probe to a programmatic variable and reference the last 24 hour average pH value?

Basically what I’m trying to do is have my doser dose kalkwasser overnight when the pH value falls below the 24 hour average pH value. And then I’ll slowly increase the average pH to be closer my desired level.

I have everything currently working except for the daily update to the pH value.

Thanks for any help!
– Chris

 

[Lasse]

I can see 3 major difficulties in this

1 Calculate the average 24 average
2 A slow increase
3 Automatic update

1) I can´t today not see any way to automatic calculate the 24 average - however there is a manual way. Use the graph and the possibility to show 1 day and you can read the average.

Maybe this will change when the function of GHL API is working

But till now I think you have to manually change the nominal value by hand

2, The normal operation of the controller is twoposition controller (red mark). If you instead use pulse variable (blue marking)) you can set how long time it should be active (pulse) and how long it should wait (pause) before next cycle. In my case 10 sec (max) on cycle and always wait 1 minute before next. The program sense how far away from your nominal value and adapt the length of the pulse from that. You have to test which length gives the smoothest adaption curve

I use the function for my heater and here you can see temperature and run time for that heather when I use a fixed nominal value

The pulse is 4 minutes and pause 30 sec. Its a fast process (heater and probe close to each other in the same apartment of the sump. In your case - probably a shorter pulse and longer pause - but test

3. Out or my league for the moment - maybe the API can solve this in the future

Sincerely Lasse