FZONE 2.5L Aquarium CO2 Generator System Carbon Dioxide Reactor Kit DIY Co2 Kit with Regulator And Needle Valve For Aquatic Tank (2.5 L with solenoid))

After carrying out a lot of research I decided this system would be the best bang for bucks system for my 120L system. I've been running the generator for 3 months now and I'm really impressed with it. It was easy to set up and the raw ingredients are cheap and easily purchased from Amazon. The powders are added and then the water is added very slowly with the bottle at a 45 degree angle. pouring it slowly slows down the chemical reaction and stops you wasting gas as you screw the regulator on to the bottle. I was getting 2 weeks of CO2 from one charge and when I added a CO2 reactor that figure went up to almost 4 weeks. 4 weeks of CO2 from 200g of acetic and 260g of Bi Carbonate is in my opinion amazing. The regulator is easy to adjust and the solenoid valve works as it should. The kit itself contains everything you need, except the raw materials and a drop checker. These can be picked up cheaply from Amazon. CO2 has made a big difference to my plants and algae growth is virtually zero now. This kit has been the best piece of kit I have bought for my aquarium in a long time. If you want to add CO2 to your system this is a great straight out of the box solution.

This is excellent. I was wary of complicated systems and setups but on trying this one its an easy mix of citric acid and bicarb and Ive had over a month of CO2 so far. Easy to set up and easy to adjust the bubbles per second. Has made a visible difference to my plants. Green and lush and visibly improved growth. You can put it on a timer easily with the included solenoid. The bottle is top quality too. Excellent set up and super glad Ive added this system to my tank.

Great product, easy to use just the manual was really poor. It never mentioned the solenoid and how to use it, I had to use YouTube and the bent glass but that sits on the tank where the tubes connect is really fragile and not very well made, I broke mine first day. Other than that it’s a great product my plants have doubled in growth.

The cheapest way as far as im concerned when introducing Co2 to your tank. This is so easy to set up, I purchased this item about two weeks ago and found the diffuser not very good so removed it and purchased an inline diffuser fitted to the outlet pipe close to the filter as possible. I also have the solenoid on a timer so its not running 24hrs, this is a must so you dont hurt your fish. Im running at one bubble every five seconds for eight hours and it works for me and *dont forget to purchase a drop checker*.

I took a while to decide on what would be the best CO2 system for my tank and settled for one where I did not have to keep buying replacement canisters and I could buy the ingredients cheaply on Amazon. I have now been using this for a fair few months and it has been a great addition to my planted tank. It was very easy to set up and with the addition of a couple of YouTube videos made it even easier. The size of the canister is not too large but I still need to think of a way to hide it. Make sure that you put the plastic tubing into hot water first so that you can get a good seal on all the components and you should then have no leakage of CO2. I did buy a different diffuser from Amazon as that seemed to be the only weak point but through my research I knew this beforehand.

Wouldn't recommend at all. Barely a month in of using and the solenoid has already stopped working. Avoid.

This is my first CO2 system. Decent quality and easy to set up. No ingredients are included but cheap to buy. I highly recommend you check this system out on YouTube before you buy. Add the baking soda first then the acid as it's less reactive and covers the soda. Use cold water and pour slowly at 45 degrees. Make sure you have attached the filter and have the valve at hand as the reaction starts fairly quickly you have time to attach the valve but I wouldn't hang around. Make sure the needle valve is closed and you can attach the solenoid and fill the bubble counter with water and it's easier to connect the air line to the bubble counter before you attach it to the valve. It says 45min to 24hrs to pressurise. It hit 50psi almost straight away so I connected the airline (softened with hot water) and the diffuser on the other end. Used the suckers provided. It doesn't include a non return valve which will stop water going back into the cylinder. The needle valve is very sensitive but didn't take long to adjust to 1 bubble a second. Overall very pleased and it's cheap to run. I've got it connected to a smart plug timed to only be on when the lights are on. When refilling you may have some crystals in the bottom. Empty everything out and add boiling water just enough to cover the crystals. Leave it for 5 min then fill up with cold water as the cylinder gets really hot. Pour out the water and the crystals will be gone.

I’ve purchased the FZONE 2.5L Aquarium CO₂ Generator System (with solenoid) three times now, and unfortunately each unit has had some kind of issue. When the system is running properly, it does its job well. It produces stable CO₂, the regulator and needle valve allow decent control, and it’s a convenient DIY-style setup for planted tanks without going full pressurized cylinder. For the price, it’s an attractive option. However, reliability has been inconsistent. I’ve experienced failures with different components across the units, which is frustrating — especially when running CO₂ on a planted tank where stability is important. Overall, it’s functional and affordable, but quality control could definitely be improved. I’d rate it 3/5 — good concept, just needs better durability.