You can order the reagents from various on-line sources. But if you use the chlorine test at 25ml, it takes 5 drops to get 1 FC. At 10ml it only takes 2 and that is enough. I think I last used the 5 drops in 25 ml about 5 years ago.
So you know:
Alk Up! and similar alk t/a raisers are nothing but Arm and Hammer Baking Soda.
pH Up!, soda ash and similar pH raisers are nothing but Arm and Hammer Washing Soda (comes in a yellow box, usually next to the 20 Mule Team Borax).
They are the same chemicals in expensive packages.

Tri-chlor pucks can be heaven-sent--or the bane of your existence. You need to have the CYA test to know. Right now, since my pump died, 4 pucks in a floater are a blessing, keeping my pool clear, and I run my robotic cleaner once a day to turn the water over.
But, if you don't watch the CYA level, before you know it, it will go over a 100ppm and then normal levels of FC won't keep it clean, and the pool store will tell you "you have chlorine lock"--there's no such thing. If you check the best-guess table JimK linked to, you'll find that for EVERY level of CYA, there's an effective match range of FC levels.

CYA slows down chlorine's action, which is a two-edged sword. It acts like sun-block to keep the UV from breaking down the chlorine (which can take as little as 15 minutes) but you need higher levels of chlorine to maintain a sanitary pool. So, our moderator, aylad (Janet) lives in Louisiana where the heat and sun eat chlorine like it was junk food. Jan keeps her CYA at a high 80ppm, and just keeps her FC between 5 and 10ppm. That way, she doesn't have to add chlorine all the time. I, living in NJ, where it gets very, very hot, but the sun isn't as intense, usually keep mine at around 40, and keep my FC between 3 and 6ppm. That way I don't have to add chlorine more than every couple of days. In the Dog Days of August, I'll raise CYA higher and keep a higher residual FC level, for the same reason.

Pucks also are very, very acidic. Had a friend at the gym ask me: "Why do I keep have to add Alk Up!? My pH is always going down?" Nice guy but not on our forum. Answer was simple: "Your pucks drive your pH down. Use bleach or liquid chlorine instead".

Hope this all helps.