I blew the dust off of this and brought it home. It's easy to set up. Giving 4 stars because the diffuser doesn't work correctly at first, it was just spewing out huge bubbles. I had to soak it in hot water, disassemble the diffuser, and blow hard through it to get it "loosened up". Day 2 the hose blew off the diffuser because pressure couldn't get through the stone. Day 3 it's working perfectly and my plants are incredibly happy. The instructions should really include some info on the diffuser needing to be broken in. Other than that this is a really great beginner CO2 kit.

Faulty regulator valve, the CO2 came shooting out of the bottle even with the valve closed and the threads tight. Nearly froze my fingers off.

I reviewed this a week ago and explained my bad luck with this product compared to my brother who owns the same thing and had no troubles with it at any point. My luck centered around my CO2 leaking away and wasting through replacement carts quickly. This review is to help reconcile the impact my previous one had on this product’s overall score as I have my issues with this figured out now. I looked into some troubleshooting and at Fluval’s site it recommended submerging the whole regulator underwater to verify if it’s leaking around the wheel or gauge. I did so inside of a clean cup of water instead of my tank, and it was effective. A large bubble of CO2 immediately started forming from the threads around the cart, which befuddled me because I had the cart on there VERY tight. After the discovery, I did as I said I would and thread sealed the next cart (I also thread sealed the bubble check valve, just in case). The difference was night and day! I was able to dial it to the bubble speed I wanted to and leave it alone for the 11+ hours I’m gone for work and come home to it still putting out CO2 and I still have more than 800psi in the cart after a week! Now that the biggest issue was solved, it was also much easier to control the regulator wheel. I didn’t bother reviewing that last time because it was already a very established gimmick that I had set the expectation for, but it works even easier now which says a lot as it’s still not that easy. But it’s definitely manageable. Now this thing works so good I almost don’t believe it’s the same product. Now I see where my brother and the other slightly condescending reviewers here are coming from; when you have no CO2 leakage from the regulator, this thing works awesome! After about a week of proper CO2 injection my plants are already starting to show the difference! I do recommend this product after all, but beware that if you’re following the right steps and still losing CO2 like crazy it’s not supposed to do that. But it’s fixable, and still worth it for the money. It is important to remember after-all that this is a cheap-cheap option for diffusing CO2 into your aquarium.

Works great with no problem at all. The adjustment valve takes a couple of minutes to regulate as you slowly lose pressure after each use. Other than that, it lasted me two weeks and then some, on a single cartridge. Not to mention that I even blew the hosing twice by accidentally blasting too much. Nothing but good words for this product overall it doesn't take a scientist to operate and is plug/play.

I badly want to like this product and have it work out for me as my brother is currently using this in his “55 gallon” aquarium to great success and has no problems at all with it and his plants are doing great. I know this thing is capable of working because I’ve seen it myself, but I am just not having the same experience with my 2.5 gal tank. I’ve owned this product for 10 days now and have gone through 4 total carts. I seem to have 2 different problems occur. When I go to work, I am unfortunately gone for a minimum of 11 hours, so I can’t do much intervening, but I will either set the bubble check to 1 bubble per 4-5 seconds and make sure it stays at that rate for at least 30 min and then leave for work. When I come back home, either the valve will have mostly closed itself and there is no more CO2 coming from the diffuser and have 1 bubble per 90-180 seconds or longer, or the tank will just be empty and I’ll have gone through a tank that had between 800-1000psi in half a day. Even on the days where it “closed” and barely had anything coming through the bubble check or diffuser it would still drain at least 200-300psi through the day. If it was leaking at any point through the rubber tubing after leaving the regulator, the bubble check and diffuser wouldn’t be consistent, but they are perfectly consistent. It has to be the regulator leaking somehow; my brother never thread seals his carts, but I think I will have to start doing it and hope it helps. Otherwise, I’m dumping a lot of money down the drain trying to use this on a tank that’s 1/100 the size of the one my brother is using it on, and he’s had it for nearly a year now. He’s gone through less carts than I have in that year, too. He’s also checked mine out multiple times and can’t see anything that I’m doing wrong or different than him. Use at your own risk, it seems you can either be lucky with these things, or just not at all.

I bought this for my 5 gallon. I’m really new to any kind of higher tech aquarium stuff, and I was nervous to try this. I waited like 2 weeks to set it up, just left it sitting in my drawer because of the horror stories I’ve heard about it exploding. I got it set up last night and figured I’d turn it on today, but couldn’t get the regular knob to turn in order to release a small amount of the CO2. I’m stupid, and I detached the canister and regulator thing from the tubing, and decided to unscrew the regulator from the co2 tank, that way I could loosen it without worrying about letting off too much CO2. Basically like taking apart the whole system. Well when I went to unscrew the regulator, the whole thing exploded and shot off like a rocket and made a really loud noise. Co2 sprayed everywhere. I was so thankful I removed it from the tubing that attached to the diffuser in the tank or else my fish would’ve died. This whole thing was my fault, complete user error, but I do think that the instructions are confusing and there’s really a lack of info about how to use this device, so maybe if there was more outreach it would be easier to understand. Still scary and potentially dangerous if the wrong person gets ahold of it, like me. Probably won’t ever try co2 again just because I don’t think it’s worth it at this point.

I read all the bad reviews and watched all the set up videos on YouTube. I only purchased because I had a coupon and received it 50% off. I set this up perfectly. I used thread tape on the connections. The regulator is faulty from the get go. I can understand the frustration of buyers. This is a BAD product. The cartridge was empty in less than 12 hrs. I did all the things. I soaked the diffuser stone. I watched all of the tutorials. It is just a really bad product.

For me, it has been working great. I have 2 of them. I use one in my 15g and one in my 55g. I wanted to see how they work since they were not expensive. You have to let the diffuser soak in the tank for 24 hours before you use it or you will get large bubbles and lose a lot of co2. Then use some plumbers tape on all the threads to make it more air tight and screw everything securely. Then open the valve slowly, a little at a time until you see the bubbles come out of the bubbler at one second intervals and leave it alone, it will slowly reach the diffuser and start bubbling. Be patient!