I second on Salifert. The thing I like about them is that they are tritation test kits meaning the change color from say pink to blue so there is not judging what shade they match on card. said:I have heard salifert was the best. I was thinking about the hanna Colorimeter ones...so far they have the phosphate and almost out alk( late October)...soon the calc, But im not sure if there cost effective.