You should already have some CYA in your water from the four 3" tabs you used.

Strips are notoriously difficult to read and unreliable. I use them solely as gross indicators --is there a little chlorine, some chlorine or a lot of chlorine in the water? The pH tab is tougher to read. The T/A tab is worse than the pH tab, and the CYA and CH tabs are impossible to read accurately, CYA being utterly useless.

The K-2006 is the way to go. Leslie's Online service has their Chlorine FAS-DPD Service Test Kit, which is the K-2006 re-branded by Leslies, but a bit more expensive at $70.

Still, paying between $60 and $80 (with shipping) for this kit will save you hundreds this year and thousands in the years to come.

Welcome!

Carl