Help me with my New Brackish 30 Gallon!!!

[Polkadotpuffer]

I have just recently got a 30 gallon tank, been set up as freshwater for about 2 days.
When will this be fully cycled? I have mature sponges in the filter from my other tank to make it quicker, and iam willing to put in some fish before i get my puffers to cycle it. I wanted 2 figure 8 (or one) puffers and some bumblee gobys dont know how many tho? I was gonna get the puffers as babies in freshwater then slowly get the tank to low brackish. Anyone help me with some of my questions?

[Dadof4]

If you placed mature media in the filter two days ago and didn't give it an ammonia source you may have to go through a full cycle again. The bacteria needs to be fed nearly constantly, I know it can take a few hours, but a few days I'm not too sure about (someone correct me if I'm wrong) . Read the Fishless Cycling article in the Puffer Library to learn how to cycle with out the fish.

[LilGreenPuffer]

Go ahead and put an ammonia source in there, like fish food or pure, unscented liquid ammonia, and then do some water tests and check for nitrites. If it's dead, just put the sponge filters back in the mature tank for a few days to pick up more bacteria, and then try it again.

Stocking question - you could have two F8s, and maybe two BBGs? Or if you want more BBGs, just one F8.

[Iliveinazoo]

I've read that a general rule is 1 bumblebee gobie per 10cm diameter of floor space (1 per 20cm) as they hang around on the bottom of the tank.

I'd go for however many bumblebees that this rule gives (if it's around 4 or 5) and 2 figure 8's, I can't see that many BBG's adding much waste to the tank.