I currently have it attached to a 5 pound CO2 tank under my aquarium. It works great. I've had no problems with it. very high-quality. very pleased. 😊

Running 2-3 bubbles/sec on my 170 gallon freshwater aquarium. Working flawlessly after 2.5 years of continuous use. There was a CO2 leak a year ago, resolved with a new washer, a little Teflon tape and prompt help from Customer Support. Recently there was an issue with floppy dials related to a loose internal connection. Customer Service responded within 24 hours and offered a 50% discount on a new unit or replacement with a used unit. With the purchase of this unit you are also purchasing prompt and helpful support.

The needle valve on this seems to either be stuck or simply faulty. It is stuck at roughly 1 bubble per 2 or so seconds. I followed the instructions when setting it up and while somewhat vague they weren't terrible. I also looked online to verify I was setting it up correctly. The pressure gauge shows 50 and the 20lb tank I am using is brand new and full with the valve wide open. No matter how much I adjust the needle valve the flow does not change. Will try to contact the company and depending on what comes of that I will adjust my review accordingly.

After tinkering with it for some time I found the issue was the shipped power cord. FZONE's customer service is great they stayed in contact until the issue was figured out and whatever I need replace they were willing to ship it out to me. The kit works as expected. If anyone is having an issue where the needle valve doesn't seem to be adjusting and only sending one bubble out, check and make sure you hear an audible click when the solenoid turns on. If it doesn't not it may also be the power cord and contact them, they will make sure to get you situated.

I've been doing high-tech planted tanks for nearly a decade years now. When I bought this unit, I did a lot of research to find the best balance of price, quality, and size. Now that I have the FZone, I couldn't be happier, it is exactly what I was hoping for.

Overall satisfaction with product: High

Impression of build quality: High
Product feels very solid. There is no plastic on it. I expect it will last for years to come.

Impression of Needle Valve: High
I've used a lot of needle valves over the years, and this one is the best I've used. It has fine grain control over the bubble count; and once set it does not seem to drift. I appreciated the inscription showing which direction to turn; as this is a frustrating guessing game on other regulators.

Impression of Regulator: High
Adjustment of the regulator is straightforward. Once set; it does not seem to gain or lose output pressure.

Impression of Bubble Counter: High
It looks clean, professional, and exactly like what you want on your showcase tank. Reading the bubbles is straightforward and consistent.

Impression of Pressure Gauge: High
The gauges are large, written in psi and kg/cm2, and easy to read. Having the second 'tank' pressure gauge helps identify when the tank is getting low, that way I have the chance to refill it before it runs out.

Impression of Relay: High
I appreciated the quick-disconnect near the relay; as my electrical strip/outlet is not easy to access.

Impression of unboxing/accessories: High
The packaging is what I would expect from a high-quality product. It includes a bottle wrench; which I was happy to have when I needed it. I was also pleased to see an extra set of o-rings was included; no manufacturer thinks to do this anymore.

Impression of Customer Support : Very High
I have reached out to Fzone with minor issues in the past. They responded very quickly and were very personable and helped me with my issue. I was very impressed. Just try to get that kind of customer service or product quality commitment from the big guys!

Overall, it's hard to not see that FZone wants to be the best in the industry. If they continue producing products like this and supporting their customers like they did for me in the past; I believe they will achieve it quickly.

Edit/Update 18 Jul 21: Going strong and stable. While no CO2 system hooked up to an aquarium with live critters should be called "set and forget", this one at least allows me the possibility. I've bumped the rating up a star. It has little issues, and mine did have that cosmetic chip in the bubble count chamber, but functionally this is giving me everything I needed and wanted. It is a simple matter of longevity from here, and the relative material quality gives me a good feeling that this should give me a good number of years.

Original:This replaced a 9 year old Milwaukee that had its solenoid stick open overnight, causing the usual scenarios of scrambling to fix a situation gone wrong.

Upsides: This unit has heft, and that's a good starting indicator for quality, the slightly higher price for comparable units seems to be invested in the materials used. Pieces were lose or had shaken in transit, but were packed well and easy to tighten up. I appreciated the additional packed o rings. The needle valve for flow adjustment is actually really nice, kinda stiff but great for making small adjustments. Installation was simple enough, but I would advise beginners watch a youtube video or something, cuz...

Downsides: The instructions for installation were printed in multiple languages on a single sheet of paper, which is fine. Translation was good enough but I KNEW what they wanted in each next step, and I could see being misled by misunderstanding were that not the case. Also, it was printed very small, with giant empty spaces of white available for ticking up the font size. (I know I am getting up there in age and need to address some age related nearsightedness, but this drove the point home in an exaggerated microfiche way...)

Additionally, my bubble counter chamber has a small chip on the outside, which hopefully remains cosmetic in nature. I also notice the solenoids power cord connection on this unit impinges (just barely) on a standard 20lb CO2 cylinder, preventing a true 0 and 180 degree up down installation. More like 5 and 185, but it works. Finally, despite manufacturer claims otherwise, I find the solonoid runs quite warm compared to what I am used to, nor am I used to the solenoid closing and not cutting pressure immediately... this one needs to bleed out a bit of excess over 2 or 3 minutes, which is definitely unnerving if you arent expecting it...

This is a four star value normally, pending nominal continued use. I believe I can expect to get 3+ years of service out of something like this, but will be watching closely (as any C02 user probably should). My review recieves an additional mark down for the chipped bubble counter.