I just got my geo not too long ago and it has turned out to be a great reactor, i like the reverse flow so the media dont compact and i would also recommend a ph controller so you dont come home one day and your media isnt melted. I like using the larger schuran style media
get a good quality regulator, you dont want to skimp on that...and a 5 lb bottle and your good to go.
dial it in slow...better to be a little low at 1st than to dial it up and have to work backwards to bring all the levels down back into check.
You will need a feed pump a mj 1200 works fine for me or something like a aqualifter. geosreef and you can check them out.