Who Gives A Fish Forums

To convert my aquaone 320 to a marine tank, I'd need to know what equipment I'd need to get. Would I have to change the filter, or maybe just upgrade it? And what about the heater, is it suitable for a marine tank or would I need a new one?

I've got a spare tank lying around, an AquaOne 320, and it's been collecting dust for 2 years. I was thinking of converting it to a marine tank, but I'm not sure if it's big enough.