Hi, I don't think it is as black and white as that, it depends on a number of other factors, amount of useage and sunshine for instance means you may use more chemicals, also if you buy a pool pal/wizard it can reduce the amount of chemicals you would need. The 2 main chemicals is Chlorine and PH, it depends on a individual how much Chlorine they prefer in the pool and the guide is PH should be between 7.2-7.6 and Chlorine at 0.3-0.6 ppm, these are with a pool pal/wizard which I would highly recommend to reduce your chemical useage. Cost of a tub of Chlorine start from around 60TL and should last a season no problem and a bit more again it all comes down to useage as the more you use the pool the more chemicals are needed, to breakdown, body sweat, sunscreens etc deposited in the pool when used.A pool pal costs between 100 & 150 TL and lasts 3 years but will need active minerals every season added to it. Hope this helps.