KH Director KH control settings?

Hello,

I have been using the KHD to adjust Carbonate dosing for about a month now. First I used the adaptive mode and then switched to the add-on control mode about two weeks ago.

Normal carbonate dosing is set at 4ml 24x per day (96ml daily total).

When I had the adaptive mode I set it at a volume change of 100% and a max and min dosing limit at 50% with 4 tests a day.

I was getting daily variations of from 0.4 to 0.7KH.

So I decided to try the add-on control since I know how many ml of my carbonate solution are needed to raise the KH by 1 in my tank: 60ml.

First I set the volume change at 12ml and a max of 3 and a min of 3. Still pretty large daily variations.

Now I am trying the following:

- Increasing testing from four to six times a day.
- Kept the volume change at 12ml but the max is now 8ml and min is 4ml.

My thinking is that the combination of the increased testing frequency and the larger corrections will reduce the daily variations.

So my questions:

1. Do my settings make sense?
2. What are others experiences in terms of daily KH variations when using the KH control feature (and what are your settings)?
3. Which control method minimizes variations the most: add-on or adaptive?

Inputs appreciated! :)

Thanks, Laith

Hello Laith,

The min / max change should be set higher than the volume change.

• Min / Max values are the boundaries that tell the KHD by how much to adjust by WHEN the KH value is greater than 1dkH away from the nominal value.

This prevents the KHD from making a drastic change to your existing dosing schedule. I suggest setting the limits to about +/- 25% from the volume change.

Hi Vinny,

Not sure what you mean by 25% of the volume change when you state just above that that the min/max should be set higher that the volume change?

Thanks!

Clarified to +/- from the volume change number.