I would also run the dosing heads that are responsible for dosing the 2 part at speed 0 or speed 1 at the most. It will be more accurate the slower they go when dosing so few ml. I would personally recommend speed 0 for sure when under 5ml
Ok we need a fulll 24 hours of tests of no changes to the tank, including water changes to make 100 percent sure it is correct. If it remains at 7.9 what we will need to do then is a 1 time dose to
Place it Back af 8.0.
But glad to see it running steady now we are close
If I calculate the difference in KH between the KH I should have after four hours given the dosing amount (with the adjustment) and the KH that is measured every four hours, I'm consistently under by around 0.2-0.3KH.
Therefore, my conclusion is that I need to increase the base dose before making a manual adjustment.
So what I propose is:
1. Increase base dose to 4ml (from current 3.8ml).
2. Monitor for 24 hours.
3. If necessary, adjust KH one time with a manual dose adjustment.
After the above I should be dialed in, at least for the current alkalinity consumption rate in my tank.
I will reduce the carbonate dosing pump speed to 0 this weekend and re-calibrate. @WWIII you have a valid point about better accuracy at lower speeds, thanks! I was reading that the basic standalone BRS dosing pump runs at 1.1ml/minute...