sera Flore Carbon-dioxide Aktiv Reactor

This has been installed for 4 months and still going strong. As it dissolves nearly all the CO2, there are no small bubbles in the tank. My Co2 monitor has stayed a health dark green.

I bought 3 of these Sera Flore CO2 reactors (2 x 1000 + 1 x 500) for my 2 aquariums (more on why I bought 3 latter) and was about to return them all for a refund after a small flood with them all because they leaked (more a flood) water from around the main screw thread where you screw the bottom half to the head. However, after searching the internet to find out why some people have success with these and I wasn't (surely all three can't be faulty) I learned you need to lubricate the screw thread and o-ring to get it to seal.100% pure silicon oil is safe with fish and planted aquariums so I bought that, lubricated the screw threads and 0-rings and they now work without leaks and they work well. I have 100% Co2 absorption in my 230 + 140 litre tanks with the 1000 (large) unit. I went for the bigger (1000) unit thinking it might have less flow reduction effect and better chance of full CO2 absorption, but the head unit is the same for both the 1000 and 500 units, on the 1000 unit the lower casing is longer. So no difference in flow reduction, they both reduced the flow of my 800 l/h and 1400 l/h filters by a noticeable amount but I think the flow with lily pipes is still OK. In terms of CO2 absorption I think the smaller 500 unit would have worked for me as only the top 2cm has co2 in it.I recommend buying double tap valves for the inlet and outlet as it will make cleaning a lot easier when needed.I have two aquariums, the reason I bought 3 units was I broke the small co2 nipple off one of them when the first flood occurred. As you can imagine it was a panic to stop the flood and in doing so the co2 line pulled sharply on the unit and it broke off (as many others experienced). Overall I am happy but they should come with a little lubricating oil so people don't suffer the leakages. I will post the same review under the larger 1000 unit.

Installed on outflow of working pump but not used yet as CO2 delivery not set up. Looks like it will do a great job at a very reasonable price.

Co2 inlet port snapped off.Fortunately we were in the room and noticed the water level had dropped. Nothing had moved or changed and it wasn't under any stress. Just brittle plastic.If we hadn't been in the room it would have flooded a 350L tank to the external filter inlet..... a lot of water.

Really struggling with this... it seems to have slowed down the flow of my filter I use the tetratec 1200 for 240ltr aquarium.. I switched to this from an in-line diffuser as I didn’t like the mist of bubbles that came out of the spray bar.. however this one just seems to gather gas at the top then the propeller stops!!! It’s getting me really frustrated... I’m going to slow down the co2 it’s currently getting about 8bps maybe this is too much... I may update this review if things improve..UPDATEtried moving the reactor closer to filter to try and get more flow as the propeller just keeps stopping and my co2 levels have dropped considerably since swapping to this from my in-line diffuser.. I am giving up and going back to my diffuser, I’ve missed the return window as I’ve faffed on with it for that long... so gonna have to try to sell it.. I’ve read reviews and watched you tube videos on it and most people seem to rate this very high but I just couldn’t get along with it at all...

Ok but very delicate. The first one had to be returned as the nipple for the co2 input broke off. No tiny bubbles in the take so dissolution rate is great.

Solid snd so much better than the other cheap and flimsy stuff out there and good price

These are honestly terribly made using cheap materials. i haven't broke mine, but i can see how so many people have. the co2 connection is ridiculous, one little knock and it will break, leaving lank water draining out to the level of your inlet pipe. when you get it installed and online the impellers don't turn without serious modification. a quick google is all it takes to establish how you can make this device work correctly, by simply "cutting bits out with a Stanly knife" or "shaving this and that". the point is...... Why??? if you think it would be nice not to have bubbles all over your tank, think again, the pearling from you plants (you may not have noticed due to the normal co2 bubbles) will make you realize you have wasted your money chasing the dream of no bubbles. do yourself a favor and by an inline diffuser.Edit- this product does what it should! I feel a bit bad due to my honest review. It does provide a way of dissolving co2 into your tank without “adding” bubbles.... it is almost silent in operation when you manage to prime it correctly! So long as you don’t try to pull off the co2 tube you prob won’t break anything. It’s hard to install because the tubing from external filters (fluval being the exception) are really not that maluable, so getting it connected is an absolute mare! (Not really a fault of the unit itself) there is the possibility of massive improvements, but they would make it cost limiting. If your patient and thorough, it’s honestly a good bit of kit