Pool Tip #49: Pool Chemical Adjustments

Download Pool Tip #49: Pool Chemical Adjustments (PDF format, 32KB)


Note: Dosages required to chemically adjust 10,000 gallons of water per 1 ppm


Chlorine Compounds
Sodium hypochlorite (10%)	1.5 cups
Sodium hypochlorite (12%)	1.3 cups
Sodium hypochlorite (15%)	1.0 cups
Lithium hypochlorite (35%)	10.5 ounces
Sodium dichloro-s-triazinetrione (60%)	2.25 ounces
Calcium hypochlorite (65%)	2.0 ounces
Trichloro-s-triazinetrione (85%)	1.5 ounces
Gas chlorine (100%)	1.3 ounces


Neutralize Chlorine
Sodium thiosulfate	1 ounce
Sodium sulfate	3.2 ounces
Hydrogen peroxide (35%)	2.6 fluid ounces


Total Alkalinity
Lowering total alkalinity with sodium bisulfate (Volume ÷ 47,056) × ___ ppm desired change = ___ pounds Lowering total alkalinity with muriatic acid (Volume ÷ 125,000) × ___ ppm desired change = ___ quarts Raising total alkalinity with sodium bicarbonate (Volume ÷ 71,425) × ___ ppm desired change = ___ pounds Raising total alkalinity with sodium carbonate* (Volume ÷ 113,231) × ___ ppm desired change = ___ pounds
* Use sodium carbonate only if both pH and total alkalinity need to be raised, and TDS and calcium hardness levels are low — otherwise a white calcium carbonate precipitate will form


Calcium Hardness
Calcium chloride (100%)	1.6 ounces
Calcium chloride (77%)	2 ounces
Sodium hexametaphosphate	6.4 ounces (initial dose) 1.25 ounces (maint. dose per 2 weeks)


Stabilizer
Cyanuric acid	1.3 ounces


Langelier Saturation Index
SI = pH + Af + Cf + Tf – TDSf

Temp. F°	Calcium Hardness	Total Alkalinity	TDS
66	0.5	75	1.5	50	1.7	<1000	12.1
77	0.6	100	1.6	75	1.9	>1000	12.2
84	0.7	150	1.8	100	2.0
94	0.8	200	1.9	150	2.2
105	0.9	300	2.1	200	2.3
		400	2.2	300	2.5
		800	2.5	400	2.6
		1000	2.6


Pounds per PPM
If the chemical is 100% full strength (Pool volume × 8.33 pounds per gallon) ÷ 1,000,000 = Pounds required for 1 ppm If the chemical is less than 100% full strength, calculate ppm by Pounds for 1 ppm ÷ Decimal strength = Pounds required for 1 ppm