Accuracy of expired test kit?
 

Just opened an Elos Calcium test kit for the first time since I bought it. Exp date on the box is 04-13 (shows how long it has been since I tested:redface:). Tested super low - 150. Is that even possible? Since I have some STN going on with a few SPS I'm wondering if I should put in a somewhat heavy dose of calcium tonight or wait until I can pick up a new test kit tomorrow and go from there?

Expired test kits are notoriously famous for wrong readings. I don't think the reading is every close to what it actually is.

I hope you're right. Tested my Alk with an Elos kit which was also expired and it was way high. I'll post the results with new test kits in the next day or two.

Well buddy all I can say is if you're dosing calcium in your tank and your sps is not massive colonies then the test kit may be wrong....

My ca never dropped that low even without dosing for a few months although I didn't have much sps at the time.

If your sps is STN it could be alk too low or unstable and fluctuating or predation.

If your alk is high the tips usually burn from my experience.

Good luck man, hope you figure it out. Also you can raise ca 100ppm per day safely.