Tiny airbubbles after filter change - Is this normal?

[oceanjumper]

I have my SW tank set up for 15 days now. Today, after I changed charcoal, filter foam & wool in my filter (Fluval 404), the tank is filled with tiny airbubbles (for over two hours now). I don't have corals yet so it won't do too much harm now. However, I was wondering, does this always happen with saltwater? Can this be avoided? Thanks

 

[slothy]

this is normal, they well tend to slowly got away... nothing to worry about

 

[musipilot]

Normal. Do a search on CARBON..then decide if you want to still use it in your SW tank. Most people don't, but reserve it for use once a week, or to clean out a medicine or treatment. Check it out.