Although I feel this meter is accurate "enough" for my freshwater tanks it concerns me that even after the smiley face pops up that the ph continues to show numbers going up and down then eventually slows down to "almost" settling on a number/reading. However, that number is ALWAYS totally different from the number that it was on when the smiley face popped up. So I am unsure if I am to assume the number that was showing when the smiley face popped up is correct or if the number it finally settled down to is the actual reading. Things that make you go hmmm. If I have to rely on "accurate enough" I do not see myself "settling" for this meter when it comes to my saltwater reef tank. Although my freshwater tanks don't concern me as much if it's "close enough", when it comes to my saltwater tanks this could spell disaster financially. There's a light years difference in losing a $4 fish than losing a $150 fish, not to mention the cost of my corals.I was disappointed to store the meter in the Apera storage solution (purchased separately) then power it up 36 hours later and the readings were wayyyyyy off. I then recalibrated it with the 7 and 4 ph solutions that came in the kit and then the readings were much more "normal" than the original testing. My problem with that is I would have thought it would stay calibrated at least for a few tests before having to be recalibrated again after the initial calibration. Also, in the kit it states the calibration solutions must be replaced after 15 uses. Since I check my tanks at least every other day I can see this being an ongoing saga and inconvenience.Another thing I realized upon arrival is that I can't get an accurate reading on my saltwater tank unless I purchase the 10 testing solution, which does not come with the kit but I was aware of that. I just assumed once calibrated the meter would test ph all the way up to 14, as the parameters online stated. I could be incorrect but from my reading all about the meter, calibration, etc I have to assume without that 10 calibration liquid I can't test my saltwater, as it is up in the 8 digits so going over the max of 7 (the highest solution in the kit) then I won't get an accurate reading over that 7. However, I am no scientist so I may be wrong in that assumption???I did go online to see about buying the 10 calibration solution only to find that I have to purchase a whole "kit" that includes the 4 and 7 solutions, at the tune of another $33. Perhaps I would be ok with that if they sent another storage container to use to test the 10 like comes in the initial test kit with the meter for the 4 and 7, and if I felt I was not going to have to recalibrate my tester after every single use. If this turns out to be the case I am leaning more towards returning it.The main reason I gave it as many stars as I did with all the many negatives I feel come with it is due to the good customer service I received when I made a call to the manufacturer.I plan to reach out to the manufacturer, Apera, again soon to see if I am doing something wrong. If I am doing things correctly and I find I have to calibrate after EVERY use I will definitely be sending it back.