While I agree that in certian tanks the les chemicals the better however, what is the strontium being used for?
I think that regular water changes do replenish lost additives from the water however that are some additives that never will be replaced unless by other means. Basically, I do what my system responds too. If adding the chemicals is a healthier environment, I do it. Granted, the fewer chemicals used the easier it is on the ol' wallet!!
Just my two bits....