Just completed a drain & refill and added stabilizer a few days ago to bring CYA levels up to 30 ppm. My TF100 test is currently reading between 20-30 ppm (right in the middle). After doing some searching here, I'll be rounding up to 30 and maintaining my FC levels from there. Am I making the right move here? Or should I add another 10ppm to try and bring it between 30-40pm?