Okay -- I have received the two extra 100ml bags of Purigen I ordered via Amazon, and put one in the Aqueon QuietFlow 55 filter and the other in the AquaClear 110, next to the one that was already running in there, so they're side by side, on top of the PhosGuard pouch. In the Aqueon, I have placed the bag in that "intake" chamber of sorts, which is kind of where the incoming water from the intake tube bubbles around a bit before it's passed on to the bio grids and cartridge media -- I have placed the Purigen bag in the Aqueon upright (as it really cannot lay sideways in this HOB) in that "chamber" area before the cartridges, but is that okay? It seems like the incoming water is indeed passing through the bag...
Also, something strange I have noticed and I am wondering if it's considered normal -- in both the Aqueon and AquaClear 110, the Purigen bags seem to be "swelling up" in the media chambers, to the point that I pulled them out to check on them (even the brand new ones placed in just yesterday) and they appear "puffy" and "blown up," causing them to float around a bit in their positions within the filter chambers. Is this just due to the water flowing through the bags? Is this normal? I did rinse both new bags before putting them into the filters.
Additonally, my AquaClear in particular has begun a strange "pumping" behavior with regard to its water flow return -- it seems since stuffing the AquaClear 110's media basket with the sponge, PhosGuard, now the two Purigen bags and the ceramic bio noodles, the water return exhibits this weird "pumping" behavior sporadically, in which the water return flow will sort of "belch out" and make a jerky turbulence in the water. Admittingly, this also began happening since I played with the filter's adjustable flow valve, and lowered the flow power due to the turbulence in my tank when it was on full power flow. Is this motion of the water return due to overstuffing my AquaClear's media basket with all this media? Is it causing too much strain on the filter's pump do you think? The media in the chamber of the AC 110 also appears to be swelling and rising -- the ceramic bio rings on top are definitely not submerged under the water in the filter completely, and the entire media load appears to need to be "pushed down" into the basket constantly, as if all the media is rising and "blowing up"...it's the weirdest thing. Could this be an indication that the sponge block for mechanical filtration in the AC 110 is loaded with debris and needs to be rinsed? I rinsed this sponge and did maintenance on this filter not too long ago...
Any insight or assistance would be greatly appreciated at this juncture.