liquid vs powder test kits

I didn't even know that there were powder kits. Who makes them?

Use Salifert and never be in doubt again.

I've used the powder tests. Not for nitrates, though, but ammonia and iron. They work just the same. I compared results with my trusty liquid test, and it was basically identical. The only difference is that the powder is hard to dissolve, it takes quite a bit more shaking than with liquid reagants. I'd say ease of use is the only real difference.

I'm willing to bet that the liquid reagants are just pre-dissolved powder or crystal solutions, anyway. They've just made it a little more convenient for us

i was told today that the powder NItrate test kits seperates Nitrite from the readings. If there is a little Nitrite, the liquid Nitrate test will show elevated readings. Test for Nitrites next time to see.