# item.guide
Side-by-Side Comparison Outdoor Living

Pool Water Chemistry vs. Propane Tanks

Comparing 2 standards across 16 specifications. 16 key differences identified.

Comparing:
Pool Water Chemistry
Propane Tanks

Residential swimming pool water chemistry standardizes balance parameters: pH 7.2–7.8 (ideal 7.4–7.6 matching human eyes), Free Chlorine 1.0–3.0 ppm, Total Alkalinity 80–120 ppm, Calcium Hardness 200–400 ppm, and Cyanuric Acid stabilizer 30–50 ppm.

View full Pool Water Chemistry spec sheet →

Portable LP propane cylinders standardize capacities from 20-lb BBQ tanks (4.7 liquid gallons / 430,000 BTU) fitted with Type 1 QCC1 / OPD overfill valves, to 1-lb disposable camping cylinders and 100-lb residential cylinders filled to the 80% legal safety limit.

View full Propane Tanks spec sheet →

Specification Comparison Table

16 Parameters
Parameter / Spec
Governing Standards
ANSI/APSP-11 / CDC Healthy Swimming Guidelines DOT 4BA / NFPA 58 / CGA Standards
pH Level (Ideal)
7.4 to 7.6 (Acceptable: 7.2–7.8 | Matches human mucous membrane pH 7.4)
Free Available Chlorine (Pool)
1.0 to 3.0 ppm (parts per million)
Free Chlorine (Hot Tub / Spa)
3.0 to 5.0 ppm (Higher due to hot water organic load)
Combined Chlorine (Chloramines)
0.0 to 0.2 ppm max (Values >0.4 ppm require shock treatment)
Total Alkalinity (TA)
80 to 120 ppm (Buffers against rapid pH bounce)
Calcium Hardness (Plaster)
200 to 400 ppm (Prevents plaster etching and metal heater corrosion)
Cyanuric Acid (CYA / Stabilizer)
30 to 50 ppm (Shields chlorine against UV degradation; >100 ppm causes lock)
Langelier Saturation Index (LSI)
-0.3 to +0.3 (Balanced water: negative = corrosive, positive = scaling)
1 lb Camp Cylinder (16.4 oz)
0.24 liquid gal | 21,500 BTU | 1"-20 UNEF disposable connection
20 lb BBQ Tank (Universal)
4.7 liquid gal (17.8 L) | 430,000 BTU | Tare: ~17 lbs, Full: ~37 lbs | Dimensions: 17.8" H × 12.2" D
30 lb RV Cylinder
7.1 liquid gal (26.9 L) | 649,000 BTU | Tare: ~24 lbs, Full: ~54 lbs | Dimensions: 23.4" H × 12.2" D
40 lb Commercial / Patio
9.4 liquid gal (35.6 L) | 860,000 BTU | Tare: ~29 lbs, Full: ~69 lbs | Dimensions: 29.3" H × 12.2" D
100 lb Residential Tank
23.6 liquid gal (89.3 L) | 2,160,000 BTU | Tare: ~68 lbs, Full: ~168 lbs | POL valve
80% Legal Fill Rule
Tanks filled to max 80% liquid volume to allow thermal expansion
OPD Valve Standard
Overfill Prevention Device (triangular valve handle) mandatory on 4–40 lb tanks