New tank problems.

[toxai]

Hi ! I bought some activated carbon and now the skimmer is making bubbles. The air flow was blocked and it has been like that from the beginning, as the noise it makes now it is doing bubbles, was inexistent before.
I'll upload how does that go. I hope the activated carbon and the skimmer working propperly solve the problem so I can add some fish this week.

 

[toxai]

How long do you think should it take for the tank to get fully cristaline after adding the activated carbon ?
I added it yesterday's evening, and after all night It doesn't look different actually.