HOB Filter Upgrade?

[Dirt Diggler]

I have a question regarding filter media for my 45 Gal African Cichliid tank but first let me give some back story:

OK, so I was reading up on HOB filters a while ago, when I stumbled on a review that mentioned using the old BIO-3 clam shell cartridges, and a roll of blue/white pond filter media to make your own filter cartridges, as an upgrade to what comes in a HOB filter cartridges (The review was less than kind to Tetra's Whisper 60 Bio-Bags). Me, being the thinker that I am have decided to take it a step further. I have the clam shells, the pink/white pond media, as well as Matrix Carbon, Chemi-Pure Elite, Cobalt Zeolite, and Marineland AC/Ammonia blend. I made "sandwiches" with the filter media in the clam shells, 2 with each product. I also have Matrix, but seeing as Matrix is a Bio-Filter, and not a Chemical Filter, I choose not to include it in the sandwiches (no sense throwing away good Matrix). The Matrix was put into fine mesh bags and added to the HOB filter in the same manner that AquaClear does their filters. I have a Tetra Whisper 60 which fits the clam shells perfectly, and an Aqueon 55/75 which has bigger slots and don't fit quite as nicely (I'll figure that out when the time comes). So far I replaced both filter cartridges in the Tetra with 1 Matrix Carbon Sandwich, and one Marineland Sandwich and stacked the old Bio-bags in the Aqueon as there was plenty of room. I didn't want to lose the bacteria I had in those Tetra cartridges so they will be in the Aqueon for a few weeks. I also added a mesh bag of Matrix, and another mesh bag of Matrix Carbon. This is kind of an experiment at this point as I don't know how the tank will react to this "upgrade", but I will be testing levels daily (ammonia, nitrite, nitrate). I have quite a few fish in there, but they are all juveniles and I have some time before I have to get a larger aquarium, or begin to purge fish.

The question is: Did I do everything correctly? The old filters remained in the system while the new ones were put in place to prevent a mini-cycle. And I'm using what I assume to be good chemical filtration. Does anyone have any advice or insight that might be of assistance in this endeavor?