I am contemplating changing to the mineral springs system this year. One place tells not to use regular salt as it can damage filter, metal, liner, etc. Another place says it's ok. If I change, do I add the same amount of Beginings every year or just the first year. And the renew as needed? My pool is an inground, 24x44. Vinyl liner, approx. 40,000 gallons of water. Depth is 3.5 feet to 8 feet.