SoCoTechDiving
 Schedule a Fill
Tech Diving · South County, MO

Clean gas.
Honest fills.

Full-service technical diving gas station serving the St. Louis dive community, and every diver is welcome. From a recreational single-tank air fill before the quarry to custom trimix blends for the deep stuff, we mix it right, check it twice, and never rush a fill.

See our services View pricing
3442
PSI Fill Pressure
99.5%
O₂ Grade Purity
7
Days a week by Appointment

Five core services. One clean fill station.

New diver topping off a single tank for the quarry, recreational diver on nitrox, or a CCR diver prepping bailouts for Roubidoux Springs, you're all welcome here. We have the gas, the gear, and the patience to get your fill right.

/ 01

Compressed Air Fills

Filtered, dry, breathing-grade Grade-E air fills to 3442 PSI. Bauer compressor with high purity filtration. By appointment, and air fills are done while you wait at drop-off.

That same clean air fills paintball and HPA (high-pressure air) tanks up to 3600 PSI, too. Just bring the fill adapter for your tank and we'll top it off.

Grade E Breathing Air Up to 3442 PSI Paintball / HPA tanks All divers welcome
Starting at
$10
/ 02

Nitrox Blending

Partial-pressure blending for EAN 32, 36, or any custom mix from 22% up to 100%. EAN 22-40% is $20, 41-100% is $40, any size SCUBA tank. Every blend is analyzed by you and us before it leaves the shop. Bring your analyzer or borrow ours.

EAN 22-40% Enriched to 100% Any size tank Verified twice
Any size tank
$20 / $40
/ 03

Trimix & Heliox Blending

Custom helium-based blends for cave, wreck, and deep diving, mixed with UHP (ultra-high-purity) helium on every blend. Bring your gas requirements and I'll fill your tank.

UHP helium Custom He mixes Deco gases CCR diluent Bailout stages
 
$40 + $3/cu ft for He/ tank
/ 04

100% O₂ Fills

We fill aviator-grade (ABO) oxygen for decompression cylinders, CCR oxygen tanks, and rebreather bailouts. All O₂ service equipment is dedicated and oxygen-cleaned. Price covers AL40 or smaller; larger tanks are more.

Aviator grade is held to a tight moisture limit, so it stays dry. Medical O₂ can carry enough water vapor to freeze a regulator at depth or invite internal corrosion, so the drier gas means cleaner tanks and regulators you can trust.

Aviator grade (ABO) 99.5% min purity Low moisture / dry O₂-clean tanks only
Per fill AL40 or smaller
$20
/ 05

Visual Inspections (VIP)

Annual visual inspection per PSI/PCI standards. I pull the valve, inspect the tank interior, check the neck threads, re-grease or replace the o-ring, and issue a fresh VIP sticker. Air fill is included.

A cylinder holds thousands of PSI, and the trouble hides inside. Moisture, rust, and cracks form where you can't see them, so a tank that looks fine can be unsafe within. It's why most fill stations require a current sticker before filling.

PSI-certified Required to fill Same-day air fills
VIP+Air Fill from
$20
Gas you can trust

Every tank is CO-analyzed
before it leaves the shop.

Carbon monoxide is the one contaminant you can't catch on your own. It's colorless, odorless, and tasteless, so a bad fill smells and tastes exactly like a good one. The trouble is that CO binds to your blood far more readily than oxygen, and the deeper you go the worse it gets, the same trace amount becomes meaningfully more potent under pressure at depth.

Contaminated fills are rare, and that's exactly the point: they happen rarely enough that nobody expects one, which is why a quick analysis matters. We test for it so you never have to wonder. It's a small step that takes the guesswork out of the most important gas you breathe.

Why we screen for CO

  • You can't detect it. No smell, no color, no taste, so your senses won't warn you in the water.
  • Pressure makes it worse. At depth, even a small amount of CO has an outsized effect on your body.
  • Symptoms hit fast. Headache, confusion, and loss of consciousness can come on with no warning underwater.
  • Analysis catches it. A quick CO check confirms the fill is clean before you ever clip the tank on.
100%
of tanks CO-analyzed before they leave the fill station.

A small shop that runs like
a serious gas blender.

Air fills while you wait

Air fills in 15-20 minutes at drop-off. Nitrox/Custom trimix blends need a day or two.

Tech-trained staff

PSI/PCI Visual Inspector Certified. I dive what I mix. I'm an active cave and wreck diver.

Every blend documented

Mix Sticker applied to tank after analysis using DIVESOFT He/O₂ Analyzer or you can bring your own.

SoCo Tech Diving's fill bench: a Bauer breathing-air compressor beside a rack of steel and aluminum dive cylinders and assembled regulators, with daylight coming through the bay window. South County, MO

The bench behind every fill.

Bauer Capitano compressor with auto condensate dump and high capacity Grade E breathing filters. Connected to 2 High Pressure Banks and an Ingersoll Rand blending panel. Oxygen and Helium on tap for blending. Electronic and air powered booster.

Bauer compressor High-purity filtration Partial-pressure blending CO-analyzed

Honest rates. No fill-station markup games.

Single-tank pricing below. Trimix is priced by cu ft of helium, call/text/email for a quote.

Service
Mix / Spec
Pressure
Price
Air Fill - Standard Breathing-grade Grade-E air, AL80 or similar
Grade E Breathing Air
AL80@3000, HP100/120@3442, LP85/95@3442, etc
$10
Nitrox - EAN 22-40% Standard nitrox blends, analyzed before pickup
EAN 22-40%
Any size, up to 3442 PSI
$20
Nitrox / Enriched - 41-100% High-O₂ blends, analyzed before pickup
EAN 41-100%
Any size, up to 3442 PSI
$40
Trimix Blend Custom He/O₂/N₂, bring your gas plan
Custom Trimix
Up to 3442 PSI
$40 + $3/cu ft He
Pure O₂ Fill - AL40 or smaller O₂-clean cylinders only · aviator grade
Pure 100% O₂
AL40 or smaller, up to 3000 PSI
$20
Pure O₂ Fill - larger than AL40 O₂-clean cylinders only · aviator grade
Pure 100% O₂
Larger than AL40, up to 3000 PSI
$40
Visual Inspection (VIP) Annual PSI/PCI inspection + sticker + air fill
Single tank
N/A
$20

South County's tech
diving gas station.

South County's only Full Service Fill station for SCUBA.

Get in touch

By appointment only, hey I gotta dive sometime right! Air fills can be done while you wait and we chat about your latest dive trip or a new piece of gear you got; everything else gets dropped off and picked up a few days later. Nitrox/O₂ can usually be done next day. Trimix needs several days notice to allow the mix to settle and get accurate analysis, please plan ahead!

Address
SoCo Tech Diving Located off Telegraph Road
Phone
(314) 329-5783 Call/Text/Email for Appointment
Email
chad@socotechdiving.com For trimix quotes include tank size and desired mix/final pressure.