KH test kits hagen vs Azoo?! two different unit of measurement?

[alvchong]

Q: for testing of KH, i use hagen KH test kits, i need around 9 drop of the reagent = 90 mg/l according to instruction booklet, since most pple talk about dkh, so i convert according to some forumer by dividing 17.8 to get around 5dkh. aftet that, i bot the Azoo KH test kit, i also need 9 drop to turn the colour but this time the instruction from azoo said: 9 drop = 9 dkh? what happened? same quality of water produced two set of hardness? how am i to determine the Co2? if my hardness level is different with this two test kits?

made in canada vs. taiwan.... fren...anyone pls enlighten me.

[wasabi8888]

How much tank water to you use to test for each test kit? 10ml of tank water each?

[alvchong]

5ml to test

[vinz]

Simple.

1. Get a pail of water. make sure you known the ammount of water inside. If not, a simple calculation should give you a safe approximate (because the kits are not that precise anyway). But the larger the pail of water, the smaller the % of error.
2. Test the KH with both kits. Note the results.
3. Add a known amount of Bicarbonate of Soda to raise the KH by a known amount.
4. Test the water again with both kits. Which one gives you the expected result?

[GaspingGurami]

Malaysia tap water KH might not be 0 deg. Better to use a bottle of Distilled or RO water to test.