I could see it too. You could run several filters in an aquarium with nothing living in it and just add ammonia to cycle them. I imagine that they would have to be sent some kind of expedited shipping though.Done correctly I can see this being a good service. Once I have a tank cycled I re-use the filter media in multiple tanks. For first timers it means they can get their fish faster rather than waiting weeks for the fishless cycle or going through extensive water changes for a fish in cycle. Consider if the stores sold cycled kits, your kit comes with the tank, filter, light, substrate, fast growing plants, and inoculated media for the tank. More satisfied first timers, fewer cases of "all the fish died" and an excellent opportunity to educate the new fish keepers about the cycle. Now stores sell the tanks fish and filter and expect the owners then to research the cycling on their own.
Not saying this particular vendor is doing a good job with uncontaminated bacteria, but it seems like it might be something that could be helpful to a lot of people just starting out.
I like Aquaclear. I also have an Aqueon Quietflow that has the same kind of set up with a cartridge insert. I just cut a piece of foam to size and put it in place of the carbon filter media. I also put some bio beads in a mesh bag in there for added bio filtration.Yes you could us the innoculated sponge if you cut it to fit in the new filter. I have used Top Fin, HOB, style filters and I would honestly say I don't recommend them. They don't have good bio media capabilities and they expect you to change cartridges. You might want to consider something like an Aquaclear (no cartridges), or even a foam filter like the company is offering. I have an Aquaclear 70 with a sponge filter and ceramic biomedia that has been running unchange, but cleaned from time to time, for over 5 years now.
The biggest problem I have with AC's is that they are pretty bad at self priming. My Quietflow no problem. After a water change, all I have to do it plug it back in and it gets right back to work. AquaClear, I have to fill up the reservoir in the back to prime it or else the motor will just run dry. Sometimes the impeller gets stuck. First couple of times, I took the filter apart to clear it. But since then, I've learned that just giving the back of the filter a couple of good knocks right behind the impeller can shake it loose and start it back up.I have reduced my number of Aquaclears from its peak of over 30 to the current 18. I have replaced them with air powered Poret cubefilters and Hamburg Mattenfilters- the Poret foam is the key. I even use it in the ACs and one of my canisters.
The only AC media I have ever used are their sponges. When they began including their Bio Max, and therefore raised the price, I always threw it away unopened. Then a friend asked me if she could could have it when I added more ACs and she got it. All of my AC filters are loaded identically--> two sponges with filter floss between them. The floss is replaced weekly as it takes too much time to clean and return it. As the AC sponges wore out I replaced them with the Poret foam. I have been using this since 2012 or so and, to date, I have not had to replace any of it. You can put any kind of media you want into an AC as long as it is not too big to fit.
I have used A marineland Emperor 400 and have small tetra WHipser on a 5.5 gal tank. I even tried the Eheim Liberty hang-on which I really liked, The problem is they only go to a 200 gph model and I run several the AC 70s (300) and one 110 (500). But I also use the 20s, 30s and 50s. The Liberty has a limited number of sizes and also the media options are not wide open the way the AC is. I will never use filter cartridges- that design is designed to enrich the manufacturer and not to help the fish keeper save money.
This is a drawback for Hagen/Fluval who makes them. I still have the first ever AC filter I got almost 22 years ago and it has run the entire time. They rarely fail in any way. Usually one manages to crack or break the plastic portions. The do need to have the impeller well and the impeller cleaned. Failure to do this may mean that a power blink or outage can mean they do not restart when electricity returns.
Followup to this. Now I've been pretty good about cleaning the filter media. I give the pre filter sponge and the mechanical and bio media a good rinse in old tank water every water change.The biggest problem I have with AC's is that they are pretty bad at self priming. My Quietflow no problem. After a water change, all I have to do it plug it back in and it gets right back to work. AquaClear, I have to fill up the reservoir in the back to prime it or else the motor will just run dry. Sometimes the impeller gets stuck. First couple of times, I took the filter apart to clear it. But since then, I've learned that just giving the back of the filter a couple of good knocks right behind the impeller can shake it loose and start it back up.
I've asked the people I live with that if I'm ever not home when the power goes out to unplug my filter. I put duct tape around the cord at the plug so they know which one it is. I have a backup sponge filter going in the tank so it won't go without filtration in that time.