HAGEN fl 20g Co2 Cartridges 3pk

This is a passive co2 system. You will not see microbubbles of co2 diffusing. The CO2 is dissolved into the water column. If you have a smaller tank (20 gal or less) this is a good system to boost slow growing plants without a large investment.

These little tanks last about a 3-4 weeks when used right. there a bit pricey but well worth it to have reliable CO2 and healthy plants

Only downfall is that the canisters only last two weeks each

If you fill the plastic reservoir once a day one canister will last the better part of a year. Fill it in the morning and then at the end of the day and you're still looking at 5 or 6 months. The plants do really well, the tanks are inexpensive, the whole system is great.

1 cartridge has lasted me just over a month so far.

I learned after the purchase that this is an inferior product from more fish keepers. I tried to return it for a better model, but Amazon would not allow the return. No place on the ad. did it say the item could not be returned.

These replacement cartridges are so easy to change out! I ordered these for my planted aquarium along with the Fluval 20g CO2 Kit. They came on time and the items are exactly as described. I will order these again when I run low on refills. Don't bother looking anywhere else.

I was happy with the product itself, however I was very disappointed with how it was advertised on the internet. It leads one to believe that it is 88 grams per bottle, and in all actuality it really is only is 20 grams per bottle. I felt like I was mislead into what I was purchasing, even though the product itself is a good product.