Reddit reviews 15 Pack of 16 Gram Threaded CO2 Cartridges

From the looks of it, you're using the Fluval co2 20g kit right? If so, the regulator will definitely fit on 16g threaded cartridges like these (you can find cheaper ones with a little more searching). Never had any issues with the co2 as far as its quality goes.

This so far is the best review I can find.

I currently own a 30" 24/7 on a 20g long. It's an amazing light but highly recommend doing co2 if you want to use 24/7 mode. For a 10g you could probably get away with Fluvals 20g co2 kit for $25 on amazon. Also that co2 kit does work with regular 16g co2 threaded cartridges like these.

like 1, basically.

depends how thorough you want to be with flushing air out of your carboy or whatever you're doing. i flushed mine using maybe 3/4 of the cartridge (obviously no way to know this for sure), then came back to it again when i needed it next, and it was empty. (i think my injector/dispensor deal was pretty cheap and probly leaked) so from then on i just used a full cartridge each time. good news is they are (sorta) cheap. but not 5lb C02 tank, cheap.

I'm using that setup in a 5 gallon Fluval Spec right now. Ditch the diffuser it comes with, its huge. Get the this [one] (https://smile.amazon.com/Fluval-Ceramic-88g-CO2-Diffuser-Ounces/dp/B004GCO35G/ref=sr_1_1?ie=UTF8&qid=1486225190&sr=8-1&keywords=Fluval+diffuser)

You can also get threaded mini co2 canisters much cheaper than the fluval brand. $23 for a 15 pack. Each one lasts me about a month on 6 hours a day/ 1 bubble per second. link

Its a bit cumbersome, the valve takes some time to get used to. The slightest twist will either be too much or nothing at all. Its not automatic so you basically have to touch it twice a day, once to turn it on and once again to off. IF you have any questions let me know