On Mar 25, 7:58*pm, (L u) wrote:
I don't have a sponge in my filter.

Lu uses an undergravel filter.............

Your right that one should not change all filter media at the same
time nor rinse and clean items with tap water, and to use water change
water if possible. No sense killing off good bacteria with chlorine or
fresh water when we work so hard to get the bacteria there inthe first
place.