You seem to have a good handle on things. I would test the pH more often than once per week however unless over a period of time you find that yours stays pretty steady. As far as shocking the pool, you actually don't ever have to routinely shock a pool as long as you keep your chlorine in the appropriate range based on your CYA level and have a CC reading less than 0.5ppm. When it is necessary, you can simply add a large dose of bleach to take the bleach up to shock level. You say that you add enough chlorine to get back to 5. This means that it is getting below 5 which is putting your pool at risk of an algae bloom. With a CYA of 90, you don't ever want to let the chlorine go below 5pp. Speaking of CYA, yours is already kinda high at 90. If it were my pool, I would quit using the trichlor pucks and just stick with bleach.