Test Kits

I use a combination of Hach and Salifert except for KH and then I just use the plain old Tetra dKH test it measures 1/2° per drop and since I am a really old reef aquarist I just can't wrap my head around alkalinity versus carbonate hardness since you end up with more or less the same information and I need the KH test for measuring CO2 the way I do in freshwater

 

well I would like to refract this statement and say I am starting to see the problem with the red sea test kits. after picking one up for ph the color doens't match anything on the card that came with it but it will match up with the old card from my previous test kit.:-/
also after getting another calcium test there is a 50ppm difference between the two. I think its time to find better test kits. just thought I would share my experince with the red sea test kits.