I’ve been using hanna alk checker. It’s been pretty consistent but recently I noticed the alk had increased more than expected. It was reading 10 yesterday. It was 10.5 five days prior. I rechecked using the diy test using 500 mL (drawn up with a 50 cc syringe 10x and then confirmed weight with a kitchen scale) and the diy test gave me 8.2
The alk reagent itself had an expiration date of 9/2023 though it was stored mostly in a cool dark place. I’m also at the last cc or 2 of the reagent so it’s possible the remainder is more concentrated
For another question. I have an apex and I disconnect the probe and attach it to a handheld pinpoint marine to check for the diy test (the two readings of tank water are identical). What’s the best way to use a checker? I could get another probe but I hate throwing them out every year. Is this my best option? Would litmus paper or a pH pen be good enough for the diy test ?
The alk reagent itself had an expiration date of 9/2023 though it was stored mostly in a cool dark place. I’m also at the last cc or 2 of the reagent so it’s possible the remainder is more concentrated
For another question. I have an apex and I disconnect the probe and attach it to a handheld pinpoint marine to check for the diy test (the two readings of tank water are identical). What’s the best way to use a checker? I could get another probe but I hate throwing them out every year. Is this my best option? Would litmus paper or a pH pen be good enough for the diy test ?