Hi Kim, I myself wouldnt use the bio wheel or any other mechinical type bio filtration. Live rock and your sand is going to do that job. I myself prefer a sand bed in my tank than a bare bottom tank, but if you do a remote DSB in your sump then you should be okay, it will do the same thing. My last tank had a DSB in the display but this time I plan on only doing a thin bed in my tank and doing a DSB remotely. (i've been reading that thats the way to go these days, I am still researching it myself, pro's vs con's) If you run carbon thru your filter you should really only do so for a few days to a week and then take it out unless there are reasons why you are running it that I dont know about. You should be able to use the canister w/o running carbon or the biowheel (most canister filters will allow you too, although I admit I dont know what model you are using). Do you have a skimmer? I couldnt really tell from your post or maybe I am just to tired today..lol
Anyways the reason I was searching for your thread was to let you know that if you still have a need for more water movement that I can give you a powerhead to use. I bought it in a pinch thinking that I could use it but it didnt really work out for me so I had to buy another. Its just a cheap petco model, I think its rated 160gph but its yours if you want it. I know how hard this hobby is to do with kids to budget around, i've got 4 of the little buggers myself. My only catch would be that it never gets sold, but you are free to give it away to anyone you want as long as its not for money. Anyways let me know. I can bring it to the meet at Kim and Beths or you or your hubby can come pick it up.