Wow, you blokes have covered a lot of ground! Caco has you
really well covered. I'll chip in on a couple things. Great job on the pool and the fully-tiled look is very classy.
I have the CCL kit as well, and for the CYA test there's only enough mixture to get up to the 40 line and it doesn't reach the 30 line. If you use one if the pipettes they include (a nice touch!) and fill to the same spot with a top up of pool water, and then a top up of CYA reagent, you can get enough to reach the 30 line. Just be sure it's the same amount. It's very important to hold with two fingers from the top, so light can get in to light up the particles that are suspended. I give it a couple minutes to fully react, and in winter I warm the sample up in my pocket which also helps. For me, when I can no longer distinguish the logo, even though there's a bit of a muddy darkness in the middle, that's about right.
Trust your own test results. Pool $tores are ALL over the place in terms of results. I tried five of them with the same water. Bizarre, but that's a big part of why TFPC works so much better. After you've tested a few times and checked your technique against the standards, you're better than any pool $tore.
Caco can walk you through it without draining, and his plan is good. But in my humble opinion, because of the copper, and if you're comfortable draining, do it. Start fresh with TFPC methods and your CYA will be precise out of the gate. It's just a weight and volume calculation. You can get the volume off your water meter (maybe you already have that) and use PoolMath which is highly reliable. If you give us the quantity of Tropiclear, we can calculate how much copper you added, but reality is that it's best to never add copper, ever. Everything can be done with chlorine, including mustard and black algae.
Did you use Start-up Tec? It's a metal sequestrant used to protect plaster from metal stains and will protect your grout the same way. If the pool is fairly new, there may be enough protection still happening from the start-up tec, and if not, you may be seeing some darkening on your grout.
This is a great thread and it's impressive how much you two have gotten through already. Well done!
Finally to be on the safe side, I wouldn't be using the heater until you're happy with the water. I'm guessing you already thought of that!