I thought it looked familiar. I think your Aqua-Tech is a stripped down marineland filter without a bio-wheel. If you buy a Penguin 170 Bio-wheel, bearings, and frame you can add a biowheel to your Aqua-tech and it'll run. I'd highly recommend this modification as it will move your biological filtration to the Bio-wheel and off your sponges. Then you can maintain the sponges pretty rigorously without disturbing your bio filter. That being said this is just hearsay, I've never done this retro fit myself.
If this is true though you might be able to also use some replacement aftermarket filter frames. Dr. Fosters & Smith sell these clamshell cartridges that fit marineland filters. They let you use any kind of sponge or floss you want and it keeps it oriented properly for the filter to function. Aquarium Filter Media: Drs. Foster & Smith Bio3 Penguin Filter Cartridges
You'd probably use the ones that fit a Penguin 170. If you can take one of your cartridges and get the dimensions along with a picture I could tell you if these will probably fit. I use these and they work great.
The issue I see with just stuffing your compartment full of filter floss and calling it done is that Marineland filters are not designed to operate like that. They don't pump water in from the bottom and force it up through the filter material. They pump it in from behind and use the space at the rear of the filter as a kind of reservoir to push the water uniformly through the filter material and then up and out. If you pack the filter full of floss there's no reservoir and the flow path through the floss will bypass most of it and really reduce the effectiveness of the filter. Also, filter floss is not easy to clean. Thankfully its cheap and it can be disposed of when it gets too gunked up. If that's all that's in your filter though it'll have to be your bio-filter as well. At that point you've got the problem that your disposable filter floss now has your indispensable nitrifying bacteria on it, not good.