ok, now I'm totally confused...
So pool guy comes around and I explain what I'm doing and why, all good... my plan is to take over maintenance, but retain them for a little longer until I'm comfortable.
I explained that I have a test kit, and my CYA reading was very low so added stabiliser to 30, then chlorine to 12 to shock the algae.
I had to go to a meeting, so I left him to it and asked him to let me know the numbers he got from his machine.
Here's what he texted me:
pH: 8.1 (!)
CYA: 55
TA: 125
So he drops in a bunch of acid, back-washes etc and on his way.
This was a bit of a shock, as my initial pH and CYA are way different, so this evening (probably 3-4 hours after he left), retested... my readings:
pH: 7.0
CYA: 28
CF/CC: 13/0
Before I started SLAM, pH was ~7.3 (1 week ago), and had not retested while SLAM was continuing.
So... who am I to believe? brand new Clear Labs Kit (which I baselined), or pool guy with his electronic test kit?
Wondering how I can confirm the numbers.. or does high CYA explain why my algae is persisting?