wow thank for all this info ! I think I will go with the fx6 and the 110. Quick question about stocking I was planning on 1 or 2 Oscars and possibly some combo of the following severum, Dempsey , terror , acara and maybe a cat (son really likes the giant bumble bee...hes only 3 but really excited) no more than 4 or 5 fish. the tank is 150 gal high 48x24x30 not he 150 gal long. would I be over stocking ?
I'm no expert so someone else will have to confirm this, as far as the tank being a 150 high vs a 150 long, yes it makes a difference. As it was explained to me, most fish swim horizontally, not vertically so having the longer tank is better unless you plan on having a bunch of smaller schooling fish. Another thing to consider is if your fish will most likely want to claim a territory for themselves especially the more aggressive ones. the longer tank gives a bigger footprint or distance between the ends of the tank allowing greater distance between fish and theoretically lowering aggression because of it.
Hope that helps.
ok, either a post got changed or deleted because I would swear I read something regarding the difference between the two tanks but I don't see it now. no more reading and posting on forums when exhausted for me.
the media between the two is the same. i can say that i have never had the issues that were for mentioned earlier about the fx5. i even run the seachem matrix and a sand substrate that i guess will cause the thing to fail. well it has been two years and nothing has happened. i still have great flow, and crystal clear water.

yep ,, it's the research brain- lock ,,you start worrying about EVERYTHING(bad) that could happen,either way you go it will likely be ok... if you go with the fx 5/6 be aware of the sand issues and use proper substrate(even pool filter sand is most likely ok , because it is heavy and won't stir easily),,if you go eheim have a bucket to put it in to save from possible water damage ,,,,,,, enjoy the research... sometimes people like to "run down"the competition so you will get what they have,,or to cover up their own user caused problems,,, YOU sound like a responsible person doing your proper research ....enjoy your fishkeeping experience![]()