Tech Tips: Water Treatment Tables:

Volume Calculations

Chemical adjustments are vital to proper sanitation and water balance. Since adjustments are based on the volume of water in the pool or spa, it is important to calculate the volume correctly. The following formulas may be used:

1. Rectangular or square shaped pool
(length x width x average depth x 7.5)

Example 1:

length = 40 feet
width = 20 feet
avg. depth = 4.5 feet

40 x 20 x 4.5 x 7.5 = 27,000 gallons
(x 3.785 liters/gallons) = 102,195 liters

Example 2:

length = 32 feet
width = 16 feet
avg. depth = 4 feet

32 x 16 x 4 x 7.5 = 15,360 gallons
(x 3.785 liters per gallon) = 58,138 liters

2. Any circular shaped pool
(diameter 1 x diameter 2 x average depth x 5.9)

Example 3:

diameter 1 = 20 feet
diameter 2 = 20 feet
avg. depth = 4 feet

20 x 20 x 4 x 5.9 = 9440 gallons
(x 3.785 liters per gallon) = 35,731 liters

Example 4:

diameter 1 = 10 feet
diameter 2 = 25 feet
avg. depth = 4 feet

10 x 25 x 4 x 5.9 = 5900 gallons
(x 3.785 liters per gallon) = 22,332 liters

3. Circular Spa
(diameter 1 x diameter 2 x average depth x 5.9)

Example 5:

diameter 1 = 4 feet
diameter 2 = 4 feet
avg. depth = 3 feet

4 x 4 x 3 x 5.9 = 283 gallons (x 3.785 liters per gallon) = 1,071 liters

Adjusting pH

It is recommended that dry chemicals first be mixed into a generous amount of water in increments of about two pounds, and the predissolved mixture be distributed evenly around the pool unless directed otherwise.

Precautions

Never add water to chemicals; always add chemicals to water.
Always follow manufacturer’s recommendations and warnings on product labeling.
Never mix two chemicals together since their pH might vary and could cause an explosion or fire.

A pH range of 7.2 - 7.8 is ideal for pools and spas. Since 7.5 is the midpoint of this range, we have provided the tables below to help in adjusting up or down to this pH. After testing the pH, find the pH in the left hand column and match this with the volume of water in your pool or spa, listed at the top of the table. Since the recommendations are approximate, you may wish to initially add slightly less and wait 4-8 hours to retest the water. Keep in mind that pH adjustments will affect alkalinity.

Lowering pH to 7.5 with Muriatic Acid

Notes:

Treatment recommendations are affected by total alkalinity. At low alkalinity levels less acid may be required and at higher alkalinity levels more acid may be required.

Starting from	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
pH	—	Tsp	Pts	oz	Pts	oz	Pts	oz	Pts	oz	Pts	oz
7.6 - 7.8	—	0.75	0	1.3	0	6.4	0	12.8	1	9.6	4	0
7.8 - 8.0	—	1	0	1.9	0	9.6	1	3.2	2	6.4	6	0
8.0 - 8.4	—	1.5	0	2.6	0	12.8	1	9.6	3	3.2	8	0
>8.4	—	2	0	3.2	1	0	2	0	4	0	10	0

Metric:

Starting from	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
pH	liters	mL	liters	mL	liters	mL	liters	mL	liters	mL	liters	mL
7.6 - 7.8	—	4	0	41	0	200	0	400	0	800	2	0
7.8 - 8.0	—	6	0	59	0	300	0	600	1	200	3	0
8.0 - 8.4	—	8	0	81	0	400	0	800	1	600	4	0
>8.4	—	10	0	100	0	500	1	0	2	0	5	0

Lowering pH to 7.5 with Dry Acid (Sodium Bisulfate)

Notes:

Treatment recommendations are affected by total alkalinity. At low alkalinity levels less acid may be required and at higher alkalinity levels more acid may be required.

Starting from	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
pH	—	Tsp	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz
7.6 - 7.8	—	1	0	1.6	0	8	0	16	1	12	5	0
7.8 - 8.0	—	1.5	0	2.4	0	12	1	4	3	8	8	0
8.0 - 8.4	—	2	0	3.2	0	16	1	12	4	4	10	0
>8.4	—	2.5	0	4	1	0	3	0	5	0	13	0

Metric:

Starting from	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
pH	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
7.6 - 7.8	0	5	0	48	0	240	0	480	0	840	2	400
7.8 - 8.0	0	7	0	72	0	360	0	600	1	980	3	840
8.0 - 8.4	0	10	0	96	0	480	0	840	2	40	4	800
>8.4	0	10	0	120	0	480	1	440	2	400	6	240

Raising pH to 7.5 with Soda Ash

Notes:

Treatments in low alkalinity waters require less soda ash while treatments in high alkalinity waters may require more soda ash.

Starting from	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
pH	—	Tsp	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz
7.2 - 7.4	—	0.4	0	0.6	0	3.2	0	6.4	0	12.8	2	0
7.0 - 7.2	—	0.6	0	1	0	4.8	0	9.6	1	3.2	3	0
6.8 - 7.0	—	0.8	0	1.3	0	6.4	0	12.8	1	9.6	4	0
<6.7	—	1	0	1.6	1	0	1	0	2	0	5	0

Metric:

Starting from	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
pH	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
7.2 - 7.4	0	2	0	18	0	96	0	192	0	384	0	960
7.0 - 7.2	0	3	0	30	0	144	0	288	0	576	1	440
6.8 - 7.0	0	4	0	39	0	192	0	384	0	768	1	920
<6.7	0	5	0	48	0	254	0	480	0	960	2	400

Adjusting Chlorine

It is recommended that dry chemicals first be mixed into a generous amount of pool water in increments of about two pounds, and the predissolved mixture be distributed evenly around the pool unless directed otherwise.

Precautions

Never add water to chemicals; always add chemicals to water.
Always follow manufacturer’s recommendations and warnings on product labeling.
Never mix two chemicals together since their pH might vary and could cause an explosion or fire.

Best results are obtained by predissolving granular chlorine products, especially if you have a vinyl pool. Trichlor is erosion fed through skimmers or floating passive feeders. Simply add one Trichlor stick or puck. Do not try to break pucks, since these could burn hands.

Raising Chlorine 1 ppm

Notes:

Routine shock treatments may require a 10 ppm dose while algae problems may require even higher doses. Consult product label before adding any chemical products.

	100 Gallons	1,000 Gallons	5,000 Gallons	10,000 Gallons	20,000 Gallons	50,000 Gallons
	Tsp	oz	oz	oz	oz	oz
Sodhypo*	1	1 oz	7 oz	13 oz	1.5 pt	2 pt
Lithium	1/4	0.4	2	4	8	19
Calhypo	1/10	0.2	1	2	4	10
Dichlor†	1/10	0.2	1	2	5	12
Dichlor‡	1/10	0.2	1	2	4	11
Trichlor	—	0.1	1	1.5	3	7

Metric:

	400 Liters	4000 Liters	20000 Liters	40000 Liters	80000 Liters	200000 Liters
	grams	grams	grams	grams	grams	grams
Gas	0.4	5	20	40	80	200
Lithium	1	10	55	115	230	570
Calhypo	1	5	30	60	125	310
Dichlor†	1	5	35	70	145	355
Dichlor‡	1	5	30	65	130	325
Trichlor	0.4	5	20	45	90	220
Sodhypo*	3	35	165	335	665	1665

*This is a liquid and the calculation assumes 1 liq. oz. (10%) = 1 dry oz.
† dihydrate form
‡ anhydrous form (see product label)

Adjusting Alkalinity

Precautions

Never add water to chemicals; always add chemicals to water.
Always follow manufacturer’s recommendations and warnings on product labeling.
Never mix two chemicals together since their pH might vary and could cause an explosion or fire.

Alkalinity should be 80-120 ppm. Once you determine the alkalinity, calculate how much you wish to raise or lower it and find this number in the left-hand column. Match this with the volume of water in your pool or spa, listed at the top of the table. Add the recommended amount to the water in small increments. Since alkalinity adjustments affect pH, you should test the alkalinity and pH 4-8 hours after the chemicals are added.

Lowering Alkalinity with Dry Acid

Notes:

Be sure to note chemical precautions above. Always follow manufacturer’s recommendations.

	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
ppm	Tsp	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz
10	1.8	—	0	3	1	0	2	0	4	0	10	0
20	3.5	—	0	6	2	0	4	0	8	0	20	0
30	—	1.0	0	10	3	0	6	0	12	0	30	0
40	—	1.3	0	13	4	0	8	0	16	0	40	0
50	—	1.6	1	0	5	0	10	0	20	0	50	0
60	—	2	1	3	6	0	12	0	24	0	60	0
70	—	2.2	1	6	7	0	14	0	28	0	70	0
80	—	2.6	1	10	8	0	16	0	32	0	80	0
90	—	3	1	13	9	0	18	0	36	0	90	0
100	—	3.2	2	0	10	0	20	0	40	0	100	0

Metric:

	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
ppm	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
10	0	10	0	100	0	480	0	960	1	920	4	800
20	0	20	0	190	0	960	1	920	3	840	9	610
30	0	30	0	290	1	440	2	880	5	760	14	410
40	0	40	0	380	1	920	3	840	7	690	19	210
50	0	50	0	480	2	400	4	800	9	610	24	20
60	0	60	0	580	2	880	5	760	11	530	28	820
70	0	70	0	670	3	360	6	720	13	450	33	620
80	0	80	0	770	3	840	7	690	15	370	38	430
90	0	90	0	860	4	320	8	650	17	290	43	230
100	0	100	0	960	4	800	9	610	19	210	48	30

Lowering Alkalinity with Muriatic Acid

Notes:

Be sure to note chemical precautions on the previous page. Always follow manufacturer’s recommendations.

	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
ppm	Tsp	oz	Pts	oz	Pts	oz	Pts	oz	Pts	oz	Pts	oz
10	1.5	—	0	2.5	0	13	1	10	3	4	8	2.5
20	3	—	0	5	1	10	3	4	6	8.5	16	0
30	5	—	0	8	2	7	4	14	9	12.5	24	0
40	—	1	0	10.5	3	4	6	8.5	13	0.5	32	0
50	—	1.3	0	13	4	1	8	2.5	16	0	40	0
60	—	1.6	0	15.5	4	14	9	12.5	19	0	48	0
70	—	1.8	1	2	5	11	11	6.5	22	0	57	0
80	—	2	1	5	6	8.5	13	0.5	26	0	65	0
90	—	2.4	1	7.5	7	5.5	14	10.5	29	0	73	0
100	—	2.7	1	10	8	2.5	16	4.5	32	0	81	0

Metric:

Starting from	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
ppm	liters	mL	liters	mL	liters	mL	liters	mL	liters	mL	liters	mL
10	0	10	0	80	0	410	0	810	1	630	4	70
20	0	20	0	160	0	810	1	630	3	260	8	140
30	0	20	0	240	1	220	2	440	4	890	12	220
40	0	30	0	330	1	630	3	260	6	520	16	290
50	0	40	0	410	2	40	4	70	8	140	20	360
60	0	50	0	490	2	440	4	890	9	770	24	430
70	0	60	0	570	2	850	5	700	11	400	28	500
80	0	70	0	650	3	260	6	520	13	30	32	580
90	0	70	0	730	3	660	7	330	14	660	36	650
100	0	80	0	810	4	70	8	140	16	290	40	720

Raising Alkalinity with Sodium Bicarbonate

Notes:

Be sure to note chemical precautions. Always follow manufacturer’s recommendations.

	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
To Raise ppm	Tsp	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz
10	1	—	0	2	0	11	1	7	2	13	7	1
20	2	—	0	5	1	7	2	13	5	10	14	1
30	4	—	0	7	2	2	4	4	8	7	21	2
40	5	—	0	9	2	13	5	10	11	4	28	2
50	6.5	—	0	11	3	8	7	1	14	1	35	3
60	—	1.4	0	14	4	4	8	7	16	14	42	3
70	—	1.6	0	16	4	15	9	14	19	11	49	4
80	—	1.8	1	2	5	10	11	4	22	8	56	4
90	—	2	1	4	6	5	12	11	25	5	63	5
100	—	2.3	1	7	7	1	14	1	28	2	70	5

Metric:

	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
ppm	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
10	0	10	0	70	0	340	0	670	1	340	3	360
20	0	10	0	130	0	670	1	340	2	690	6	720
30	0	20	0	200	1	10	2	20	4	30	10	80
40	0	30	0	270	1	340	2	690	5	380	13	440
50	0	30	0	340	1	680	3	360	6	720	16	800
60	0	40	0	400	2	20	4	30	8	60	20	160
70	0	50	0	470	2	350	4	700	9	410	23	520
80	0	50	0	540	2	690	5	380	10	750	26	880
90	0	60	0	600	3	20	6	50	12	100	30	240
100	0	70	0	670	3	360	6	720	13	440	33	600

Adjusting Hardness

Precautions

Never add water to chemicals; always add chemicals to water.
Never add calcium chloride to skimmer since it produces heat upon mixing with water.
Always follow manufacturer’s recommendations and warnings on product labeling.
Never mix two chemicals together since their pH might vary and could cause an explosion or fire.

In most areas of the country a minimum of 150 ppm and ideal level of 200 - 400 ppm of hardness is recommended. The only practical way to lower hardness is to drain some water from the pool or spa and refill with water lower in hardness.

Once you determine the hardness concentration, calculate how much you wish to add and find this number in the left-hand column. Match this with the volume of water in the pool or spa, listed at the top of the table. Be careful when mixing calcium chloride with water since this can generate a significant amount of heat. Allow the water to circulate 4-8 hours after the chemical is added and then check the hardness.

Raising Hardness with Calcium Chloride

Notes:

A significant amount of heat can be generated when mixing calcium chloride in water. Follow manufacturer's recommendations carefully.

	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
To Raise ppm	Tsp	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz	Lbs	oz
10	1	—	0	2	0	10	1	4	2	7	6	2
20	2.5	—	0	4	1	4	2	7	4	15	12	4
30	3.5	—	0	6	1	13	3	11	7	6	18	7
40	5	—	0	8	2	7	4	15	9	13	24	9
50	6	—	0	10	3	1	6	2	12	4	36	11
60	—	1.2	0	12	3	11	7	6	14	12	36	13
70	—	1.4	0	14	4	5	8	12	17	3	42	16
80	—	1.6	0	16	4	15	9	13	19	10	49	2
90	—	1.8	1	2	5	8	11	1	22	2	55	4
100	—	2	1	4	6	2	12	4	24	9	61

Metric:

	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
ppm	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
10	0	10	0	60	0	290	0	590	1	180	2	940
20	0	10	0	120	0	590	1	180	2	350	5	880
30	0	20	0	180	0	880	1	760	3	530	8	820
40	0	20	0	240	1	180	2	350	4	700	11	600
50	0	30	0	290	1	470	2	940	5	880	14	700
60	0	40	0	350	1	760	3	530	7	60	17	640
70	0	40	0	410	2	60	4	120	8	230	20	580
80	0	50	0	470	2	350	4	700	9	410	23	520
90	0	50	0	530	2	650	5	290	10	590	26	460
100	0	60	0	590	2	940	5	880	11	760	29	400

Adjusting Cyanuric Acid

Precautions

Never add water to chemicals; always add chemicals to water.
Always follow manufacturer’s recommendations and warnings on product labeling.
Never mix two chemicals together since their pH might vary and could cause an explosion or fire.

Usually a 30 - 50 ppm concentration of cyanuric acid will produce good chlorine stabilization. However, your service professional may have a different recommendation. Usually cyanuric acid is added to a skimmer and travels to the filter where it may take 24-48 hours to completely dissolve. Determine how much cyanuric acid you wish to add and find this number on the left-hand side of the table. Match this with the pool or spa water volume listed at the top of the table. Keep in mind that dichlor and trichlor products will add cyanuric acid also.

Raising Cyanuric Acid

Notes:

Cyanuric Acid may require 24 - 48 hours to completely dissolve.

	100 Gallons		1,000 Gallons		5,000 Gallons		10,000 Gallons		20,000 Gallons		50,000 Gallons
To Raise ppm	—	Tsp.	Lbs.	Oz.	Lbs.	Oz.	Lbs.	Oz.	Lbs.	Oz.	Lbs.	Oz.
10	—	0.75	0	1	0	7	0	13	1	11	4	3
20	—	1.5	0	3	0	13	1	11	3	5	8	6
30	—	2.25	0	4	1	4	2	8	5	0	12	8
40	—	3	0	5	1	11	3	5	6	11	16	11
50	—	3.5	0	7	2	1	4	3	8	6	20	14

Metric:

	400 Liters		4000 Liters		20000 Liters		40000 Liters		80000 Liters		200000 Liters
To Raise ppm	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g	Kg	g
10	0	4	0	40	0	200	0	400	0	800	2	0
20	0	8	0	80	0	400	0	800	1	600	4	0
30	0	12	0	120	0	600	1	200	2	400	6	0
40	0	16	0	160	0	800	1	600	3	200	8	0
50	0	20	0	200	1	0	2	0	4	0	10	0

LaMotte Company

Tech Tips: Water Treatment Tables:

Volume Calculations

1. Rectangular or square shaped pool (length x width x average depth x 7.5)

Example 1:

Example 2:

2. Any circular shaped pool (diameter 1 x diameter 2 x average depth x 5.9)

Example 3:

Example 4:

3. Circular Spa (diameter 1 x diameter 2 x average depth x 5.9)

Example 5:

Adjusting pH

Precautions

Lowering pH to 7.5 with Muriatic Acid

Notes:

Metric:

Lowering pH to 7.5 with Dry Acid (Sodium Bisulfate)

Notes:

Metric:

Raising pH to 7.5 with Soda Ash

Notes:

Metric:

Adjusting Chlorine

Precautions

Raising Chlorine 1 ppm

Notes:

Metric:

Adjusting Alkalinity

Precautions

Lowering Alkalinity with Dry Acid

Notes:

Metric:

Lowering Alkalinity with Muriatic Acid

Notes:

Metric:

Raising Alkalinity with Sodium Bicarbonate

Notes:

Metric:

Adjusting Hardness

Precautions

Raising Hardness with Calcium Chloride

Notes:

Metric:

Adjusting Cyanuric Acid

Precautions

Raising Cyanuric Acid

Notes:

Metric:

LaMotte Company

1. Rectangular or square shaped pool
(length x width x average depth x 7.5)

2. Any circular shaped pool
(diameter 1 x diameter 2 x average depth x 5.9)

3. Circular Spa
(diameter 1 x diameter 2 x average depth x 5.9)