Gulfstream Tropical AGU00529 Ista Max Mix Co2 Reactor for Aquarium, Large

I think its a great product. I read numerous reviews on line about it that didn't give it glowing reviews because it seemed like it leaked or the impellers didn't turn. I did a DYI diffuser from PVC and its more expensive to do, for the price this works really well and is so inexpensive compared to DYI, even with some simple mods I did to prevent leaks. This is so much better than the atmoic diffuser I used to use. I feel like i wasted a lot of CO2 with that diffuser, and they need to be cleaned every several weeks, and I had them break where the hose connects. Lastly the atmoic CO2 diffuser from GLA is expensive.First i took it apart, and sanded the impeller shaft, it removed a plastic bur and the impellers were spinning easily. When I screwed the bottom back on I used teflon tape to ensure no leaking from the bottom, do that. I read reviews it leaked from the bottom, so teflon tape eliminates that. Other leak points are where the hoses attach. I used hose clamps to eliminate that problem.The device comes with nice suction cups so I attached it to the back of my tank easily. I think this helps reduce problems with complaints it slowed down the flow, I noticed they kept it in the stand next to the filter. It will reduce flow, but nothing too terrible, I drive the large model on a 29 gallon tank with an Eheim 2213 canister filter. I read that some folks have issues with the impellers stopping moving, or it filling with gas, that happens because the flow from the canister might not be enough to drive the size reactor, or you are pumping in too much CO2. It takes a little playing around to get your bubble rate right. I have mine at about 1 per second and my plants pearl every night. I see the impellers slow down at the end of the day so I might be a little under powered, or my filter needs to be cleaned. Any gas trapped will still diffuse. I turn off my CO2 about an hour before lights out, and any gas in the reactor diffuses over that time.The hardest thing was once you install it, getting the air out, but the directions tell you to turn it upside down, and it works.I have done multiple water changes and have not had to re-prime it at all.I dont have bubbles in my tank anymore, other than plants pearling, so I am getting really good CO2 diffusion. Ive been using it for a couple of months now, and no leaks (but I use teflon tape and hose clamps- I think any inline device should be help with hose clamps). Its small, it diffuses well, Great Product

Great CO2 diffusion. I never saw even one bubble. But it's so cheaply made you need to buy an extra... Mine worked great for 2 months and then it wouldn't fill up because it was leaking all over the place. Put pipe clamps on the tubing and it didn't make a difference. I read a tip on the internet: If you use the larger tubing adapters, glue them on with PVC glue. The adapters are just cheap plastic pipe with no gasket to seal against leaks. Other folks have had theirs leak from the bottom and have glued that on as well.So I'm buying a second one. I'll keep the first as a spare and glue everything together. It's a great idea, and gives excellent diffusion when it works. I'd give it 5 stars if it weren't so cheaply made.....4/03/2017 Update: PVC glue won't bond to vinyl tubing. I gave up on it and tossed it in the closet... A great idea, but a waste of money. Too cheaply made. Downgraded it to a 1.Looking at the Sera CO2 reactor. $50 on Amazon but it looks better built. It has actual screw nuts to hold down the tubing. You can get it for <$20 on aliexpress or Wish. Although I think it looks better built, $50 is too much to pay for it. So I ordered one from aliexpress. We'll see how that one works. :)

I bought this after viewing several You-tube reviews. I was aware of the complaints and shortcomings before I purchased. I decided to buy this rather than building one from plumbing fittings for two reasons; it looks better, and it costs less than the fittings did at a big box store.Here is my take on the product.The body of the reactor appears to be quite thin and looks delicate. I did handle with care, but it doesn't seem to be as delicate as it looks.My one complaint about the quality is molding flash on the output tube. I scraped the flash away and coupled it to a piece of 1/2", flexible, clear tubing. The tubing needs to be clamped, so I used a stainless steel, worm drive, clamp. I was careful to hold the reactor by the piece of tubing when tightening the clamp. Holding by the body of the reactor would likely have lead to disaster. In spite of the substantial tension on the clamp there was a very slow leak at this fitting. Patience was rewarded, and after two days the leak sealed itself.I used 1/2 x 5/8, HDPE, barbed reducers to adapt the 1/2 fittings on the reactor to the 5/8 id hose that came with my Sun-Sun 703b cannister filter. They are light weight, inexpensive and seal easily with the application of some hose clamps.I am happy with the performance of the reactor. Although it is not silent, the faint rattling sound of the impellers is not objectionable. Once purged of air by momentarily turning the reactor upside down, I have not had any problems with the function of the reactor.I have the reactor set up on a 45 gallon, planted aquarium. When I was using a glass diffuser at one bubble per second on the flow monitor, the CO2 tester never indicated any change from blue (no increase in CO2). With the same flow and with the reactor, the tester is now an obvious green. After purging the residual air in the reactor, there are absolutely no bubbles in the effluent stream.Concllusions;If it had not been for the molding flash and slow leak, I would have given this reactor five stars. I shouldn't have to rework a manufactured product before it is suitable for it's intended use. It was still worthy of at least the four stars because it was inexpensive, easy to set up and does it's job well.If I need a reactor for another tank, I will buy another one of these..