Hi NETWizz and welcome to TFP,
Here is one of my experiences with my newly acquired pool, I had never owned one before. I spent over a $1000 in 2 weeks trying to clear a pool, then found TFP, ordered a kit but wanted to get started before kit arrived so I took sample to good old pool store, they said PH was too High (do not remember # now) was told to add 5# of dry acid to bring it down to 7.2. But I was smart (or so I thought) I could use poolmath to double check poolstore, and surely a poolstore could get PH correct (or so I thought). So when I checked poolmath using poolstore test result, it told me to add half of what poolstore told me, so I did. Low and behold the next day TFP-100 came (only took a day and a half). Measured my ph and it was 6.8 which is lowest the scale will read (probably in the 5s, I have not done the math to calculate). Too make a long story short took me 2 days and 8# of borax to correct my mistake. So relying on poolstore tests is a shot in the dark. After that I tried a little experiment and took a sample to 3 different stores got the tests done within 1.5 hrs of taking sample, none of them were the same and did not correlate to TFP-100. 2 of the stores were Leslie's so they had same equipment. Try it yourself. So the correct kit is of prime importance, too much chlorine can damage equipment, too little algae will keep growing (there are also many other problems with bad chemistry in the pool). My conclusion is that my ph was probably ok in the first place and poolstore's recommendation took it way low which could have damaged equipment, in your case it could damage the surface. You may be able to use the pucks if your CYA is truly low but if you add conditioner and your CYA is too high you will probably need to do a water exchange which means draining a significant portion of water and refilling (note draining incorrectly can also cause major damage). I say all of this to educate you on why everyone is so adamant on you getting a proper kit ASAP. It is in your best interest and the TF-100 is your best bang for your buck as you will learn if you follow TFP. After my 2 weeks and $1000 at poolstore I turned my cesspool into a sparkling clear pool in a week less than $100, 2 of those days correcting ph problem poolstore gave me. Best of luck I hope my experience helps you not make similar mistakes.