Hi
I've recently setup a KH Director and it is still reporting high dKH. Reports around 2-3 dKH higher than actual value. Here is what I have tried, some of it several times

1. Measured and remeasured all the lines
2. Calculated volume by disconnecting and dispensing into a 50ml graduated cylinder - twice - this was within 2ml of measured/ calculated volume by length
3. Re-calibrated pH probe 3 times - all readings after calibration have been within .2 of 4 and 7
4. Re-calibrated dosing heads twice - each calibration within 0.5ml of each other
5. Checked for air bubbles, multiple flushing and venting reagent
6. I ordered some GHL KH reference fluid and its ran three times 10.2, 10.1 and 10
7. Hanna checker gives me a dKH of 8 (tank water)
8. KHD gives me a consistent 10.3
9. Saltwater is Tropic Marin Pro made up to std strength i.e. 1kg/30litres which should be about 7-8 dKH

I really don't know what else to check, the only thing which is odd is the waste is being reported much higher than is being produced - waste on dosing pump 3 is showing as 1439ml in the container at most its 950ml - this has been consistently high

Thanks