Haha no worries, it took me a good bit of reading to understand it better and decide how I wanted to customize my filtration.
Don't fret: the filtration you have is fine, I'll try to explain a little more depth and it can actually save you $ in the long run. Afterward, I'll edit the post with a couple articles if you're interested.
So your filtration goes in stages. Not sure you have a mechanical stage though.
1st stage: mechanical - typically a intake sponge or a sponge after your impeller (or both) and before your other filters. Used to pull out and catch larger debris (just rinse off in dirty tank water every now and again) and other large particulate matter. I use both for a 2 stage mechanical filtration.
2nd stage: chemical - typically the pads (in your case the blue pads with carbon in them). Used to catch dissolved pollutants. I use a dual-sided filter floss (polyfill basically) for a 2 stage chemical.
3rd stage: biological. Houses 1 source of your bacteria (also sources present in the substrate and some in water, but we use the filter bio media as a "homestead" for the bacteria). The key to the bio media is: the more surface area the better (more room for your beneficial bacteria). I use the ceramic bio cubes (look like small cylinders) and place them all facing the same direction (point so water goes through the hole) and cram as many as you can fit. *Edit - a lot of filters come with a type of plastic screen/sheet to work as biological filtration, feel free to scrap that and replace with something better (replace smartly though).
By customizing these you can increase the effectiveness of your filter. In your case - you use the blue pads with carbon in them. Which is fine - but activated carbon has a lifespan, and once spent when you change out the pad with carbon in it - you can affect your cycle. Always best to reuse filters for a long time, just can't do that really with filters that have carbon inside them. Activated carbon will pull out some chemicals, tannins, and some nutrients that your plants use (generally not enough to affect plant growth), so it does help to clean water - just doesn't last forever.
To save money, and help your beneficial bacteria - you can buy a large sheet of dual sided polyfill (will work as a 2 stage chemical filter) and cut out the sizes of filter you need (link below to an example of this). The sheet will last forever. Then you could switch to a small media bag and fill it with Purigen (I suggest) or activated carbon and place it before the poly. This way, you can change out the carbon/Purigen without changing the chemical filter (which also houses beneficial bacteria). During times you do need to change the chem filter, simply place a new on in the filter a few days before pulling out the old one.
Purigen also lasts a long time - and it can be cleaned/"recharged" for further use. I just bought the bag that treats 100 gallons, split it in 2, and put in media bags. Before taking 1 out for "recharging" I put the 2nd one in a few days beforehand (same as the filter floss).
I'm not the best at explaining stuff and will link some articles. Hope this helped to explain how filtration works a bit more - there are options within each stage to customize it to suit your needs.
*Edit:
HOB customization video - full of info.
*Edit: HOB customization guide (uses a topfin silentstream filter and explains various ways to customize, but all hob filters can be similarly customize, I have 3 customs filters: a topfin silentstream, a Fluval Aquaclear, and an aqueon slow-flo for shrimp - all 3 are designed different but all have same custom filtration).
This is a write-up on some methods and options for using DIY media in your HOB filter. My goal is to condense in one thread, easy and cheap methods of improving the filtration in your HOB filter while making it more cost effective. I enjoy the hobby and especially the DIY aspect of it...
www.fishlore.com
*2nd edit: explanation of filtration stages
Filtration is a vital part of any home aquarium. It allows maintainance of a healthy aquatic environment for the tank inhabitants and keeps the tank aesthetically pleasing to the viewer. There are many different types of filtration systems that can be utilized in the home freshwater aquarium...
azeah.com
Product links for a few things:
Buy Top Fin® Filter Fiber Pad U-Media at Petsmart
www.petsmart.com
Buy Top Fin® Filter Media Bag at Petsmart
www.petsmart.com
Purigen works in these media bags but the link for the Purigen I tried is broke. Its like $13.00 for a bag that treats 100 gallons (split between your own media bags). My custom filtration helped my water clarity a lot, but it's really the Purigen I credit for pulling out the smell.