GHL KH Director KH control settings...

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Laith

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One other thought. Are you using gfo in your system? If you are, gfo when new will lower the alkalinity in a tank fairly drastically (especially high capacity gfo). Then when it's a few days old, it has little effect on alkalinity. Well that causes a problem when we are automating dosing based on testing. If we adjust the dosing because the gfo has lowered the alkalinity, well then once that effect is gone, we are overdosing the tank. I've seen it and confirmed it several times. It's actually a pretty significant effect.

No, I'm not using GFO... just carbon in a reactor.
 
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And on the 20th I checked the KHD pH probe in both a 4 pH and a 7 pH calibration solution and it showed 4.02 and 7.01 respectively. So I'm assuming not a problem with the KHD.

I lowered the base dose to 2ml before the 2:30pm dose.

Curious to see what the 4pm test will show in 35 minutes now that the lights have been ramping up since noon.:)
 

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And on the 20th I checked the KHD pH probe in both a 4 pH and a 7 pH calibration solution and it showed 4.02 and 7.01 respectively. So I'm assuming not a problem with the KHD.

I lowered the base dose to 2ml before the 2:30pm dose.

Curious to see what the 4pm test will show in 35 minutes now that the lights have been ramping up since noon.:)

Seems like it's just gonna take a little time to really nail down what the tanks consumption really is currently. One other thing you can do is test every 2 hours for a couple days, but that shouldn't be needed. No sense wasting khd reagent when the tank really shouldn't change that much every couple hours. Will be interesting to see where this goes!

I don't think it's a kh director issue. Unless somehow there's bubbles in the reagent line.
 
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The 4pm test returned a KH of 8.7 and a new dose adjustment of -37%. This more or less fits in with my calculations.

Peak light period is from 3:30pm to 8:30pm so that should lower the KH as demand picks up.

Let's see where this goes...
 

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Sorry forgot to post mine :)

4C3A68A7-F2EE-4E22-BB45-9D25453523A5.png


I am now at +3%
 
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The 8pm test returned a KH of 8.4. As I thought, the peak light period has increased the carbonate uptake because without the extra uptake the KH should have been around 8.6.

The calculated adjustment is now -20%. I can imagine that by the midnight test the KH may be down to 8.1 or 8.2 also due to the continued light period.

As an aside, for the past several days the dosing head that takes takes in the sample for testing has been squeaking... and the reagent dosing head makes a sort of grinding noise. When I first installed the Doser it was silent... anybody else have this? (I know that the previous head covers posed problems but this was purchased end of January this year and the blue covers have that hole/marking that shows they are the new version).
 

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@Laith - good to see that it is reducing slowly downward and not rising.

It should be approx 8 hopefully by morning and then we should begin to see the adjustments.

Knock on wood, I have not had the squeaking issue, you should put in a support ticket about it thou.
 
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Further tests:

midnight: 8.3
4am: 7.9

Before the 07:30 carbonate dose, increased base dose from 2ml to 3ml.

8am: 7.8 and now showing an adjustment of 12%

So, if over let's say the next 24 hours there are more adjustments upwards than downwards I should raise the 3ml base dose to 3.5ml? and vice versa?
 

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That is Correct we already know it having an issue keeping up.

To raise your system fron 7.8 to 8 how much do you need? Do they have a calculator?
 

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Ok we are staying steady which is a good thing we just need a full 24 hours to now know for sure the next adjustment.
 
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Test at 4pm: 7.6 with a calculated adjustment of 20%.

Tempted to raise the base dosage as the KH seems to be headed downward, even with the adjustments. Lights have been ramping up since noon...

Yes or no? :confused:
 

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Adjust to 3.5.

We may need to also do a manual dose to help compensate. But, we will see once the 3.5 is entered.

We do not want to go above 3.5
 

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So we are now .6 off or 36 ml off.

This is through your peak correct?
 

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Hey @Laith are you sure you have the correct dosing head listed under the kh director for alkalinity and it's only listed once? Just making sure! :)

Also what speed are you using for the alkalinity doser head? It should be on speed 0. Have you watched it while manually pressing it to dose to make sure the right amount is coming out?
 
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So we are now .6 off or 36 ml off.

This is through your peak correct?

Yes, the peak lighting is from 3:30pm to 8:30pm (total light period noon to midnight).

Hey @Laith are you sure you have the correct dosing head listed under the kh director for alkalinity and it's only listed once? Just making sure! :)

Yes, correct dosing head is set (pump 1).

But: all four of the other adjustment "indexes" were marked as pump 1 as well though volume change, max and min of those four were all 0%. This must be the default setting as I haven't touched the other indexes. I've now changed all those to "none" so that only the first adjustment index is showing pump 1. I wonder what the consequence is of having the other adjustment pumps marked as the same pump as the first one?

Also what speed are you using for the alkalinity doser head? It should be on speed 0. Have you watched it while manually pressing it to dose to make sure the right amount is coming out?

It is set at speed 2. Originally it was on 3 but I thought this wasn't accurate enough. Does everyone use speed zero? I guess that is for smaller dosing amounts such as I'm dosing? Should I change it to zero? If so I'll do that this afternoon as it will need to be re-calibrated...

Yes, the doser head is calibrated and is dosing.
 
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I did a manual test at 11pm and it showed 7.1 (adjustment dose 43%)... so I upped the base dose to 4ml to avoid a further drop.

Then at midnight measured 7.2.

At 4am measured 7.5, adjustment 25%

So at 7am this morning I lowered the base dose back to 3.5ml.
 
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