Alkalinity Dosage Calculators - are they wrong for ESV?

[holy carp]

In the past, I have been using some of the online calculators for determining how much 2-part I should dose.

 

Marine Depot has a calculator, which seems to match exactly the calculations behind the time-tested JDieck calculator.

 

So in either calculator, if I enter 10,000 gallons and calculate how much ESV B-Ionic Part A needs to be added to raise dKH by 1.00, they both tell me 4464.2ml.

 

Now, if I convert that back to a dKH impact of a 1ml dose per gallon, I would get 10,000 / 4464.2 = 2.24 dKH per ml dosed per gallon system volume.

 

However, on the containers of the ESV Part A Alkalinity supplement (and on the product descriptions I found online), it states that "1ml per gallon of aquarium water will raise alkalinity by 0.74 meq/Liter (2.07 dKH)"

 

So the question is, why are the online dosage calculators based on a different impact than what is written on the bottle?  Or am I misinterpreting the math behind the dosage?  Did the concentration of ESV change at some point? 

 

[holy carp]

OK, so I'll direct this to @Marine Depot in hopes that they can shed light if nobody else can explain...  Hopefully they find this post in spite of being in the Water Chemistry forum as opposed to their sponsor forum.

 

From their website, here is the description of ESV B-Ionic 2-part:

It clearly states that the impact of 1ml per gallon is 2.07 dKH, just like it says on the printed label of the ESV bottle.

 

Here is the Marine Depot Calculator showing 10,000 ml per 10,000 gallons has an impact of 2.24 dKH (I used 10k gallons to add better resolution to the resulting ml to ensure there wasn't a rounding issue - 1ml to 1 gallon has the same dKH impact)

 

[Clown79]

I think they are wrong.

 

Told me to add 28ml. My tank actually uses 2.5ml

[holy carp]

7 hours ago, Clown79 said:

I think they are wrong.

 

Told me to add 28ml. My tank actually uses 2.5ml

Were you using dKH? I think the Marine Depot tool defaults to meq/liter for alkalinity, which would explain such a large difference. 

[Clown79]

I changed it to dkh.

I also checked multiple online calculators. 

 

I chose to follow instructions on the label per gallon and tested before and after. 2.5 gets me from 7.8 back to 8.7