killing beneficial bacteria

I already cleaned out my filter with tap water, but afterwards was told not to do that because it rids beneficial bacteria. But there's other items in the tank that can have good bacteria too right? Like the decor, plants, and gravel hasn't been messed with. What effect will this have on my...

Hello. I have a 125 gallon freshwater tank and have noticed a couple of my fish have come down with ich. I am running a FX6 canister filter on this tank and also have some plants in the tank. I am planning on using ich-x to treat but will that hurt my beneficial bacteria? I know I have to remove...