Question: will we need to introduce any new biomass to keep from starving the bacteria during this process
Yeah....it's called "live rock". I'm sure you've heard of it, and it works well.
Here's an example of why I ***hate*** external bio sumps, plastic balls, sponges, and other gimmicks. All they do is basically compete with more stable bacteria colonies that are better suited living inside natural materials such as LR
*inside* your tank where they belong and are far more robust. Otherwise, you run the risk of this nitrogen cycle merry-go-round every time you clean your external media or look at it cross eyed, because that's were you've encouraged the bacteria to grow. Ammo spikes from die offs, which in turn supresses or kills off your nitrite and nitrate reducers, and around and around we go until nitrosomas colonies get fat and happy again.
Activated carbon/charcoal is another one I try to avoid on a constant basis and I recommend only be used on occasion because it's a solution in search of a problem. I've also used about every cannister filter on the planet. Give me a bag full of filter floss and a big old back filter with cross tank return anyday. I'll use a fluval to gravel vac simply because it's easier to prime than my Magnum 350.
If you insist on some form of external biological filtration, get a Emperor 400 (or 280). That little rotating biowheel will host more bacteria than a warehouse full of submerged rip-off bio media based euro engineered cannisters. Or, you can simply take it off if you have enough LR
, which is the ideal way to keep a stable marine tank in the first place. Which brings me to another pet peeve which is that little bio-wheel easily keeping up with the ammon output on a 30 gallon feeder tank at the LFS
hosting a zillion goldfish crammed to gills, yet we are led
to believe 4 fish in a 40gal is over-crowding. Cut me some slack, people.
My advice on this is similiar to above, and that is to step WAY back and cut out the overly complex variables. Get some LR
, re-cycle your tank, and reduce your reliance on the external apparatus. I can think of a number of back filters that will do the job nicely such as an aquaclear 300 or 500 or Emperor 400 with bio-wheel removed that won't interfere with LR
- the skimmer is going crazy because the ammonia spikes are killing off a lot of biology that then gets dumped into your water table.