I suggested in an earlier post to borrow another kit to verify the results of your current kit before spending money on another one. Salifert kits are generally considered reliable. I think there was some problems with an alkalinity kit. Personally I like the Seachem calcium kit. Basically the same as Salifert, but you got a lot more kits for the $ and they are easier to find and don't go on back order the way that Salifert does.