Some water softeners that are timed to purge (clean) can be set for too long of a cycle and allow more salts to come thru. Test water just before and after the cycle to check.
On my big tanks, I usually change the water directly with my garage tap....I siphoned the water and refill through the available hose...Normally I do 40-50% water changes every Satuday or Sunday, sometimes also in mid week....I use Kordon NovAqua Water Conditioner wit every change...There also times do not have any, so it is all direct tap water....
