Maybe it's time to post some numbers and a picture of the water looking down into the pool at the stairs. Helps give a reference with clarity and distance.
Are you running the pump/filter 24/7 ??
If you are at or below 10ppm FC you can test pH. Did you ever add any acid to bring the pH down from your first posting of 7.8 to something closer to 7.2 ??
Have you added any CYA to get up to 30ppm ?? If so how much and when ?? If you added to target 30 then your FC SLAM level should be 12. The tablets do add CYA but do so slowly as they dissolve. I think the rule thumb is it's 6ppm added CYA for each tablet. So if you truly had zero CYA then in a week you should see 18 if you don't vac to waste or backwash much. So you'd still need to toss in three more tablets to get up around 30. If you actually have stabilizer it would be faster to just toss some in a sock into your skimmer or in front of a return. We don't really recommend using the chlorinating tablets but right now you do need both the chlorine and the CYA. See recommended chemicals "Free Chlorine" - - >
http://www.troublefreepool.com/content/139-recommended-pool-chemicals
How often are you testing and what is the FC dropping to between additions ?? It's helpful to us to "see" how much FC the pool is eating over how many hours.
What is your CC level at ??
If you spend a little time keeping the thread current with the pools chemistry and what you're doing it makes the SLAM easier to accomplish and the sooner you'll have sparkly blue water.
It's just a matter of staying one step ahead of the green monster.