The only way that one medium is better than the next is if it provides more surface area per unit volume. That comment about 5 square feet per pound of biomass is...strange. If you have a sump...almost any sump, but especially one as big as you plan...you have enough room for biofiltration that even the cheapest stuff will provide enough surface area for enough bacteria to do the job. And beyond that...well, it can't get better and you won't get more bacteria.
Maybe one of the expensive designer media might...might...have an advantage if you have only a tiny biofiltration compartment and need to get the most of that volume. That isn't the case most of the time; it absolutely isn't the case here.
I chuckle when I read how K1, when used in a fluid bed, cleans itself by knocking off the older, weaker bacteria and leaving only the healthiest bacteria still on the medium. Who the hell thinks that stuff up? Even if they can "prove" this in some fashion, it is in a practical sense ridiculous and meaningless. The beauty of a sump is that you have vast amounts of real estate waiting for bacteria to colonize, more than ever will be needed for almost any bioload you care to maintain. I have some K1 swirling and dancing in one sump; my granddaughters like to watch it, and I got it for free, so that's the only reason it's there.
My other sumps, full of static media, are colonized by a bunch of flabby, out-of-shape, couch-potato variety bacteria. Despite the embarrassment this causes me, I know that they still manage to gobble up the ammonia my fish produce. What more can I ask? What more do I need? I can remove half of the media whenever I wish, to start a new tank, and the old filter will be back to full capacity within a day or so. Those lazy overweight bacteria still reproduce just as fast as the more athletic ones, and they eat just as much ammonia. Enough...is good enough!
Maybe one of the expensive designer media might...might...have an advantage if you have only a tiny biofiltration compartment and need to get the most of that volume. That isn't the case most of the time; it absolutely isn't the case here.
I chuckle when I read how K1, when used in a fluid bed, cleans itself by knocking off the older, weaker bacteria and leaving only the healthiest bacteria still on the medium. Who the hell thinks that stuff up? Even if they can "prove" this in some fashion, it is in a practical sense ridiculous and meaningless. The beauty of a sump is that you have vast amounts of real estate waiting for bacteria to colonize, more than ever will be needed for almost any bioload you care to maintain. I have some K1 swirling and dancing in one sump; my granddaughters like to watch it, and I got it for free, so that's the only reason it's there.
My other sumps, full of static media, are colonized by a bunch of flabby, out-of-shape, couch-potato variety bacteria. Despite the embarrassment this causes me, I know that they still manage to gobble up the ammonia my fish produce. What more can I ask? What more do I need? I can remove half of the media whenever I wish, to start a new tank, and the old filter will be back to full capacity within a day or so. Those lazy overweight bacteria still reproduce just as fast as the more athletic ones, and they eat just as much ammonia. Enough...is good enough!