Water Change 64 Litre Tank

[Ardvark]

Been surfing various tropical forums getting snippets of info. Question has come to mind.
Some people add bacteria to the water when they do there "weekly" water change. From what I understand the bacteria we are talking about lives on surfaces and not in the water so by adding bacteria to the water there is a danger of doing more harm than good to both your pocket and the tank.
My question is this
If during the water change you clean the sponges in your filter (in the dirty water you have taken out your tank), would that process remove some bacteria? If so would it be beneficial to add bacteria at that point or would it be a waste of time as mentioned earlier?
 
                                                                                           Al

 

[Ch4rlie]

Not something I've ever done to be honest, I do not see any benefit of adding bottled bacteria to a tank on each water change, just more money to spend on buying bacteria thats not really needed!
 
On a tank and filter thats been fully cycled successfully, should never have to add bacteria of any sort as far as I know.
 
Normal routine tends to be, as you said, wash some filter media, about half, in old tank water, it may remove a few bacs but imho negligible and the bacs will very quickly get back to full strength, then re-fill with dechlored water.
 
Thats what I've done every week ever since started the fish keeping hobby and never had any issues.