Filter Media and Cycling Question

[Solaris]

I finally got around to putting my filter together, and I realised that they included one carbon cartridge ("best for tropical fish") and one zeolite cartridge ("best for goldfish"). But there are two slots in the filter. So, I guess they didn't give me enough to actually put it together properly.

My father, who was helping me put it together, said that I should just use the one for goldfish in the other slot. Is that true? I'm uneasy about doing this (he doesn't know anything about aquariums), so I didn't put it in. There is currently one cartridge and the other slot is empty. I'll try to get down to the pet store to buy another carbon cartridge.

Also, during the cycling process, is it best to keep the filter speed at maximum? And does the bacteria grow better at a specific temperature?

[Sanguinefox]

It won't hurt anything to use both. However be prepared to potential spend way too much money than necessary to replace those cartridges as they tend to dirty up fast. I used to have a filter that had that and those two inserts, neither made much of a difference.