need help to determine pool surface finish

[Melnic]

OK,
I have been thinking I have plaster pool for the chemistry, but how do I tell what it is made out of?
Bottom is painted light blue and it is rather smooth to me.
There are tiles inlayed into the steps.
I want to get this right so I know what CH range I should be targeting. Right now, my CH is at 200.

 

[atttech-2]

For chemical purposes we call all stone based products plaster. That ranges from traditional white plaster that is ground white marble to the myriad brands of quartz products. Bottom line if it is not vinyl or fiberglass, treat it as plaster. 200 ppm is a bit on the low side but not supper concerning, you could bump it by 50 ppm if you want. It depends on your fill water, if you have supper soft fill water and are not likely to see much CH rise from fill water as you top off this summer due to evaporation then go ahead and bump it up a bit. On the other hand if you have hard water I would let it be, you will be fighting high CH before you know it as the summer drags on.