So I have had my pool since Feb 2019 and ordered the Tf100 in May once I discovered this site. I’m about to be out of CYA regent. I have repurchased DPD powder x2 now and with the other kit I had prior had PH and ALK I used first. I noticed on the TF100 there are no dates of expiration. The tests haven’t drastically changed results indicating they have expired but when should I replace them?