Hanna dKH readings

[Res_Ipsa]

Howdy. I just bought a new Hanna alkalinity checker and am learning how to use it. I took a sample of my tapwater and saw a reading of 5.4. I then checked the alkalinity of my rock curing water mix (RODI plus a dechlorinator at the moment) got a reading of 0.9.

It can’t be that low???I checked that reading against the water coming out of my RO and found it to be 0.0; I repeated that test twice.

Is this user error? Equipment error?

 

[Jackony]

Does the base water and base water + reagent need to be salt water? For the test to work.

 

[pdxmonkeyboy]

Does the base water and base water + reagent need to be salt water? For the test to work.

i belive that is the issue. i would be very very surprised if it was just "broken"

test some salt water, i think you will find it is pretty consistent

 

[Randy Holmes-Farley Verified Community Expert]

I don't understand the problem. RO water will have close to 0 dKH. Tap water can be higher.

 

[reefwiser]

Dkh is measured by saltwater not RO water or tap water. Tap water you can measure hardness but that is a different test kit

 

[Randy Holmes-Farley Verified Community Expert]

Dkh is measured by saltwater not RO water or tap water. Tap water you can measure hardness but that is a different test kit

You can have and measure alkalinity in tap water, and can express it in dKH. Some US tap water is higher in alkalinity than seawater.