Need Help - Hanna Copper checker discrepancy with Copper Power dosing instructions

[Obriy]

I've used Copper Power for my QT. It's 10-gallon tank with about 9.5 gallon of water. I've always had the issue with Hanna Copper checker showing much lower copper level then what it should be according to the Copper Power dosing instructions.
Previously, I dosed more than the instructions said to reach at least 2.25. But now I have a wrasse in my tank and I really don't want to overdose.
According to the dosing instructions/calculator, I have to add 14 ml of Copper Power to reach 2.5. So far, I dosed 11 ml, which should bring the copper level to 1.95. However, my Hanna checker shows only 1.3. What could be a problem there? It's not the first time something like this happens, but the discrepancy was smaller before.
I don't have any media in my tank, except for a bowl of Aragonite sand for the wrasse. Could the sand absorb so much copper? And, before I used no sand which resulted in discrepancy anyways.
Should I go by the instructions and risk to not reach therapeutic levels of copper, or should I dose according to the Hanna checker and risk overdosing?

 

[Jay Hemdal Verified Community Expert]

I've used Copper Power for my QT. It's 10-gallon tank with about 9.5 gallon of water. I've always had the issue with Hanna Copper checker showing much lower copper level then what it should be according to the Copper Power dosing instructions.
Previously, I dosed more than the instructions said to reach at least 2.25. But now I have a wrasse in my tank and I really don't want to overdose.
According to the dosing instructions/calculator, I have to add 14 ml of Copper Power to reach 2.5. So far, I dosed 11 ml, which should bring the copper level to 1.95. However, my Hanna checker shows only 1.3. What could be a problem there? It's not the first time something like this happens, but the discrepancy was smaller before.
I don't have any media in my tank, except for a bowl of Aragonite sand for the wrasse. Could the sand absorb so much copper? And, before I used no sand which resulted in discrepancy anyways.
Should I go by the instructions and risk to not reach therapeutic levels of copper, or should I dose according to the Hanna checker and risk overdosing?

The issue I've had is that Copper Power seems to be underdosed when using their instructions. Also, watch for reagent getting stuck in the powder pillow and not getting all dispensed.

If you are planning any water changes - you can try dosing 5 gallons of seawater using a pipette for accuracy, then dose it to label instructions, let it mix and then test it.

Here is a purported copper power calculator. I have NOT tested its accuracy:

https://www.krakkingkorals.com.au/p...PgB-YnnFViwZG1-8Z0gZeeSg1YiWOOh-WtklIrubixvws

 

[Obriy]

I've checked Copper Power Dosage Calculator and can confirm that it's aligned with the manufacturer dosing instructions.
I decided to remove the Aragonite sand and replaced it with the quartz sand as it supposed to absorb much less. Will continue dosing 1-1.5 ml / day and measure daily and monitor the wrasse's behavior.

 

[slingfox]

With Cooper Power, I usually have to dose at least 10% higher than their instructions to get to the targeted level. I have put several wrasse through copper quarantine and never had an issue.

 

[Obriy]

Unfortunately, I've had Naoko Wrasse dying in the QT. It behaved normally until the last dose and died two days later. I have a Melanurus Wrasse this time and hope it is not as delicate.