Smallest resolution of control, 1ml?

[kingy138]

Morning all,

I decided to trial KHD / dosing pump control yesterday, but it doesn't seem to be making any adjustments, when I think it should be.

I believe the issue is the resolution of adjustment. Can the calculated adjustment be less than 1ml? For instance 0.2ml?
To me it seems like it only works with integers, as I cannot maintain "Adjustment ML" or min and max limits in anything but integers.

I just don't see how this would work for anyone with a smaller tank. 1ml adjustment to me is massive.

To correct 8.1dkh to 8dkh, I need only adjust by 0.4ml using Triton Core7 as it's very concentrated.

Please tell me it can calculate adjustment in decimals? If not, I'm genuinely lost for words and cannot for the life of me think why you'd do that, given that your pumps have always been able to dose down to decimals.

See screenshot, would this setup ever be able to calculate a value?
If the adjustment ml is set to 1ml, but it cannot calculate decimals, then why do you allow 1ml to be entered?

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Many thanks,
Dave

[kingy138]

I've found if I use adaptive mode, it actually calculates an adjustment %, which is promising at least.
Wonder how it'll actually behave during dosing though, as it'll be a % of a decimal.

I don't understand why add-on doesn't work though.

[Vinny]

Let's not assume it's not possible because it is.

The KHD does calculate adjustments to the tenth place. Even though the calculated adjustment shows (0), if the amount calculated is under 1ml, it will adjust by that amount as long as the pump dispensing the supplement is correctly calibrated and set to speed (0). The adjustment field only shows amounts by the whole number. Use the adaptive mode for more fine tuned control.

[kingy138]

Hi Vinny,

As said in Jerry Maguire: "show me the money"...
I've no doubt you would have developed the solution to be precision accurate, however, and it's a big however, why would you develop it to show 0 when indeed it's far more accurate?

For people dosing 100ml three times a day, the current (displayed) precision makes sense, but for the rest of us on much lower consumption why would you round to zero and make it look like it's doing nothing?

Right now you're asking me to take it on faith that magic is happening under the bonnet, when, I'm sure, we would all like to see exactly whats going on.

I do think you had high demand customers in mind for this when it was built, as even in adaptive mode, it maxes out at 50% and 100% limit. When I'm dosing 0.5ml per dose, an extra 0.25ml x 2 is nothing.
For someone dosing 100ml, an extra 50ml x 2 is massive.

For someone with a 200L tank, I'm struggling to see how I will make this work, as it doesn't seem to be responding to changes and calculating any adjustments.

Right now, I have it on adapative: 50% 100% 100%. My dKH is 8.1 and my set point 8, yet it isn't subtracting anything and continues to dose the same amount as always.
My doser is set for the lowest speed and accurately calibrated.
This isn't the problem though, it's clearly still dosing the same normal amount each time, nothing changes. The doser could easily handle the precision. 0.1ml is approximately a single drop. At the 0.5ml I'm currently dosing each time, this could effectively be split into 5, I've just manually tested the same to confirm.

[kingy138]

Hi Vinny,

Allow me to illustrate my point with real results since yesterday and please tell me what I'm doing wrong.

My dKH set point is at 8
I'm dosing at multiple intervals, 0.5ml
I have two dose 2.1 heads dosing triton 3a and 3b and set for adaptive control with parameters 50%, 100%, 100%, as this is the maximum allowed setting.

At 5:45am today, my KHD detected 7.8 dKH.
At 6:20 and 6:30 my two dosing heads were scheduled to deliver 0.5ml each.

Based on the KHD results, a change of 1% was determined, which would be 0.005ml change.
The dose 2.1 can only dose at resolutions of 0.1 and greater, so the addition of 0.005ml didn't even make it capture this information as an adjustment, as it's simply too low.

The only way to "force" the application to dose the correct amount, would be to use "Add-On mode" and set the additional ml amount to 50ml, as this would correctly calculate back to an additional 0.5ml.
I'm actually assuming this too, based on your earlier reply, as when I set an additional ml amount of 100ml, it determines an adjustment of 1ml. So assuming what you said earlier about zero rounding, then this would calculate 50ml as correct, but this isn't displayed on the screen.
Complicated, right?
Not only that, but if I ever dose 100ml of Triton 3a into my tank, I'm pretty sure everything would jump out.

I think this perfectly illustrates the point of my earlier message, the KHD control settings were indeed designed for people dosing many hundreds of ml each time and doesn't work (as expected) at low consumption.

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[kingy138]

@Vinny

Lets not do that thing where you ignore me and we don't figure this out.

Something isn't right here, please see my last comment and feedback what you think. Eitherway, it's calculating very very low % and this cannot make any adjustments for me.

Please and thank you <3

[Vinny]

You are not being ignored.
If this was still a problem, a support ticket could've been opened so we can assist further.

Based on the info provided thus far, your control settings and or dosing schedules are not set correctly for the product being used. If the calculated amounts are too small for the doser to dispense, then add-on control would be more suitable since it allows you to choose the adjustment down to 0.1ml.

It's not clear to me how tight of a control you're looking to get...

What kind of daily KH swings were you getting before you enabled KH control?
What kind of swings do you see with KH control enabled?
Are you testing enough per day to gather this information? If yes, how many tests per day?

A screenshot of your chart will help.


How many times per day are you dosing these 0.5ml?
The adjustment the KHD makes to the existing dose schedule directly correlates to the number of doses per day.