Switching filtration methods

[tonymacaroni]

I have a 26g Bow and I'm running a 75g wet/dry (with bio-balls) filter on it hehe.I want to take it off and switch to a HOB filter.Am I suppose to gradually remove the bio-balls daily or can I switch filters all at once?

 

[bertoni]

I would start up the HOB filter, and then slowly remove the bio-balls, maybe 10% per week or so. The HOB filter needs time to grow a bacterial culture.