I am about to wind down the hot water salt treatment for my fish. My question is...after I do my water changes to get the water less salty...how do I know how much salt is left in the water so I can safely put fish from a q-tank ( with no salt in the water) into the main tank, with presumably some salt in the water. Am I correct in assuming that if I do 4 water changes of 25% and add in only fresh water then by the end of the last water change I will have no salt left in the water. Or should I add some salt into my q-tank.