I'm a newbie to pools & posting, so plz forgive mistakes. I have owned an 18" X45" Oval AGP with a Cartridge type filter- pump for 3 yrs now. Always wanted a pool, but I just can't seem to 'GET' how to care for one. In past, have always tried to do the 3step process: Balance/Chlorine/Algicide, w/o much success. Idk what I told myself this Summer was the year I'd find out what I did wrong or die trying. Long story short: Illness stopped me from properly closing my pool last Fall = Algae City in Spring. Killed Algae out & I'm vacuuming daily to get it all out, but its VERY hard cause' its degraded to a whitish slime now. I DO have the PH right , BUT I CANNOT GET CHLORINE UP enough to even register and the STABILIZER is LOW too. I've tried using the stabilized solid disc chlorine but it just never dissolves quickly enough to make a difference, and by that time, PH, algea & other stuff are usually acting up. So I switched to Gallon jugs of Sodium Hypochoride thinking it would boost it quick cause its liquid (just found out its unstable). Wrong!Duh... So, my questions are 1) What type/brand of Chlorine do I need to raise it to 1-3 ppm in a reasonably quick time? 2)Do I add CYA BEFORE or AFTER the next new CHLORINE I add? Testing reveals : Hardness, PH, TA are OK. TC& FC are VERY LOW & STABILIZER LOW. Pool water has visible dead algae & possibly a bit of new growth too. I am a 52 yr old retired- disabled nurse who needs pool for exercise to help my Lymphedema in legs. Thanks to anyone who has advice.