I tested Alk in my tank with 2 API test kits, One was brand new, never before used and the other I have used for months and it has worked fine. No matter how many drops of solution I add to the test tube it will NOT turn blue. I added 30 drops and it was still yellow! I immediately went and tested my 20G and the same thing happened. I tested my tap water and after about 4 drops it turned blue. Ph (8.3) and cal (440 ppm) in my 29G seem fine. About a year ago the same thing happened but after a couple days I re-tested with the same test kit and then the test accurately measured my alk. The only thing in common the two tanks have is that recently I added a lot of baking soda to both tanks --perhaps too much but not an insane amount. I also added calcium to both tanks but Kent cal to the 20G and SeaLab #28 into my 29G. Could too much baking soda affect the API alk test?
sen, the baking soda mix you made is used to raise the alkalinity in the tank. Overdosing with the alk mix will cause the levels to go up. My question is how much of the mix exactly did you add to the tank? Its reccomended that you dont raise the dkh more than 1 a day. heres a link to instructions and ingredients to the alk mix An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
If you use any supplement with boron (or a salt that has a high boron content) it can interfere with alk readings. Boron in a Reef Tank"If the boron level is substantially above natural levels, as it is in the Seachem salt mix with 12x normal levels, borate can actually begin to dominate such tests, and makes knowing the real bicarbonate and carbonate alkalinity much more difficult."
It is either too low and I misread the test completely or it could be the boron cause I did put a supplement with boron in the tank.
also just to throw this out there, i have never ever gotten an accurate reading out of API tests, i absoutley hate them, thats just me, i have had allmost everyone of there tests and the ones sutch as calcium and akilinity never cooperated with me.