[Delphinus]

Maybe we should be checking to see if the instructions have an expiry date not just the reagents? Geeeze.

I can't say I noticed the bad math example before on the instructions but it's been a long time since I looked at Elos Ca test kit instructions in detail. The last kit I had was also consistently giving me bad readings of .. interestingly enough I think it was always 450 as well. I can't remember for sure I'd have to check my notes but I stopped using the Elos Ca test kit. I like the Salifert best. I did pony up for a Ca checker from Hanna but it has its own issues (basically you test 0.1ml of tank water which you have to add 0.9ml of lab grade distilled water (doesn't everybody have this? I carry some in my wallet just in case because you just never know when you're going to need some lab grade distilled water) and when you're doing a test on such a tiny sample it just has to be prone to fluctuating readings, I would think .. esp if you cheap out and just use "regular old vanilla RO/DI" instead of "lab grade distilled water.")