Wow, what's with the thread necromancy? This one was done for almost a year.
I see no difference in box filters than running a hydro sponge, or one of those internal power filters where you have to buy supplies that fit only that model.
There's a huge difference between box filters and almost all other filters on the market - water flow. A box filter is powered with an air pump using air to force water through it, while internal power filters or hydro sponges are powered with a motor that can move significantly more water through them. Therefore, a box filter is incapable of equaling the filtration power of any of the other filter types (except the weak Whisper filters that are also run by an air pump).
Another difference is technology. Over time, better methods of growing a healthy bacterial colony in filters have been developed. I would take the sponge and ceramic rings in my AquaClear filters over filter floss from Wal-Mart any day.
We have a local shop with well over 75 tanks every one has a hydro sponge setup, guess what they don't sell? Yeap, sponges.
Every fish store I've been to, chain or otherwise, has sold sponge filters. Why your local shop won't sell them is beyond me.
They are more than happy to supply Bio Bags for an external filter, HOB, at an expensive price, guess they don't want the 5 to 8 buck filter cost per tank per month but it is OK for you.
If you ask any knowledgeable person on these forums, I'm confident that the consensus would be to NEVER replace your filter media monthly. In fact, you should only replace it if it's fallen apart to the point that it's unusable. Even at that point, you should still put some of it back in with the new filter media to help regrow your bacteria colony on the new one.
Therefore, you don't have to spend $5-8 monthly on filter maintenance. In fact, you may not even have to spend that yearly, depending on how long your filter media lasts.
I haven't changed the filter media in my AquaClear filters since I got them, and haven't had to. Just give them a shake and squeeze monthly in old tank water during a water change, and they're good to go.
Yes it eats space in the tank but it replaced a messy, pain in the butt to clean, canister filter with the expensive filter sleeves and filters.
I can't imagine any set up where you could replace a canister filter with a box filter. Canister filters are for large aquariums and move a ton of water versus any of the other choices out there. No box filter that I've ever seen would even come close to moving that much water through it.
Honestly, if you prefer box filters, good for you. Buy them and use them to your heart's content. I was only pointing out in this thread that there are better options for filtration that aren't expensive.