An inline heater is a heater that works in the filter line (or in the filter) instead of having a seperate heater in the tank. What is the diameter of the hose for the filter?
The media you use depends on what you plan to do with your tank and your specific water. IMO
, throw away the carbon. It's a baggie of black pieces. It is only really active for about a week. After that the only advantage is that it holds beneficial bacteria. But if you were to get ceramic rings, they hold much more bacteria and never have to be changed. I am running the original bag of ceramic rings that I put in my canister filter 3 years ago.
A Sponge is a must. It is probably included with the filter already. A thick meshy material. Filter floss is also a must IMO
. It's a soft white material. It traps the small bits that float in the water. Really polishes it off. You can buy it at Wal-Mart in the crafts section. Basically batting. It's a heck of a lot cheaper than purchasing it from the lfs
. A $3 bag lasted us about a year compared to $6 every 2 weeks that it would have cost form the lfs
Anything beyond that really depends on your ultimate goal. If you are wanting to keep fish that live in a naturally high pH and your tap is low, add a baggie of crushed coral to the filter. I don't really see a need for anything else. If you keep ontop of your water changes and do proper maintenance, you shouldn't need anything to lower nitrates or the like.
Big piece of advice, ask here before purchasing from the lfs
. They will sell you 100 items when you really only need 1.