If you want to carbonate faster, don’t turn the gas up. Fit more stone. That’s the core of our advice across our videos, and this post pulls the pieces together.
The three controls
Bubble size, and so carbonation efficiency, comes down to three things (What’s Happening in Your Tank):
- Stone length, which sets how much surface area emits bubbles
- Pore size, which sets how small each bubble starts
- Flow rate, set on the FizzWizz flow controller in cubic feet per hour (CFH)
Pore size is fixed when you buy the stone. Flow rate is a dial. Length is the one you plan around.
The flow ceiling
Push too much gas through a stone and it switches from hydrophilic mode, where bubbles form inside the stone at pore size, to hydrophobic mode, where pores merge into big bubbles on the surface that race to the headspace (Hydrophilic vs. Hydrophobic).
Our rule of thumb: keeping flow under roughly 0.8 CFH per inch of stone keeps most stones in hydrophilic mode. That makes the arithmetic simple:
| Stone length | Approximate flow ceiling at 0.8 CFH/inch |
|---|---|
| 12 inches | 9.6 CFH |
| 16 inches | 12.8 CFH |
| 24 inches | 19.2 CFH |
Treat 0.8 CFH per inch as a starting point, not a hard limit. BrewWizz rates its own 16-inch WizzStone-Combo for up to 16 CFH, so check the rating for your stone and let the sight glass tell you when you’ve gone too far.
Foamy styles change the picture. Stouts and other foamy beers need slower flow and smaller bubbles than, say, a pilsner.
Matching stone to tank
A longer stone lets you run more CFH without creating big bubbles, so a bigger tank wants a longer stone. One real example: the run in Anatomy of a Perfect Carbonation Plot used a 30-barrel bright tank with a 12-inch stone, with flow rates set so the run finished overnight. The lesson from that run: as long as the stone is matched to the size of the bright tank, you get extremely repeatable carbonations.
Rather than a single rule, BrewWizz sizes flow to the whole setup. Its flowmeter guide lists four things that decide the right flow rate: tank size and the height of product over the stone, stone size and quality, and beverage gravity (brewwizz.com). Its free Stone Flow Rate Calculator takes your tank and stone details and estimates a recommended flow rate and the expected carbonation time.
The flowmeters themselves come in three sizes:
| Flowmeter | Best for (per BrewWizz) |
|---|---|
| 11 CFH, low flow | Smaller or shorter tanks with limited product height over the stone, smaller stones, or higher-gravity products |
| 22 CFH, standard (most common) | Most standard brewery tanks, stone sizes and beer styles |
| 60 CFH, high flow | Large or tall tanks with a lot of product over the stone, and stones designed for higher flow; often only needed when splitting flow between two stones |
One stone or two?
If one stone can’t carbonate a large tank fast enough without being over-driven, the alternative to a longer stone is a second one. The Splitter-Wizz lets a FizzWizz Bubbles Anywhere Edition run two carbonation stones in one tank at the same time, with a flowmeter for each (11 or 22 CFH). It works with any stone size, it’s built to order, and a second stone needs its own stone modification kit to connect.
Your plots will tell you
The best check on stone sizing is your own data. If a run takes much longer than you want at a flow rate that keeps the sight glass dry, the stone is too short for the tank. If beer drips into the sight glass, you’re flowing far too fast: cut the flow to at least half. FizzWizz logs every run, so you can compare.
Ceramic or stainless?
Both work. Ceramic’s thick wall makes it hard to push into hydrophobic mode but it’s fragile; stainless is tougher but easier to flow hydrophobic and wears over time (Hydrophilic vs. Hydrophobic). The WizzStone-Combo uses a 16-inch thick-wall ceramic stone with 0.5 micron pores, tested to 200 PSI without rupture, in a stainless carrier with a built-in thermowell.
Not sure your stone fits your tank? Try the Stone Flow Rate Calculator, or send us your tank size and stone and we’ll help you size it.
Sources
- What’s Happening in Your Tank and Hydrophilic vs. Hydrophobic (three controls, 0.8 CFH per inch, stout guidance, sight glass).
- Anatomy of a Perfect Carbonation Plot (30-barrel tank, 12-inch stone).
- FizzWizz System & Accessories (WizzStone-Combo specification).
- brewwizz.com, Flowmeter Options, Splitter-Wizz, and the Stone Flow Rate Calculator.