Too much of a water change??

[Trigger Man]

If you have been doing the 15% wc every week for 2 years with good results don't worry what others my think. I did not read the tread that mentioned 40% wc in a month being bad but i assume they meant at one time. Many people do a 15 % change a week (i do one every 10 days or so, and when I was running a heavily stocked fowlr tank I was doing a water change every 5 days to keep good water conditions). You have to remember that waterchanges depend on many things, one of the bigger ones being how much you feed, bioload and the ability of your tanks cuc and benificial bacteria to remove the undesirables. WC allow for depleted nutrients to be put back into the tank as well as a way to get the bad stuff out of the water that otherwise can not do it quickly enough by itself.