Raypak 902B pH of Water, Total Dissolved Solids, Recommended Levels, Fiberglass Pools, Types

Raypak water heaters can operate lime/scale-free using potable water with a hardness not exceeding 25 grains per gallon. Proper operation is achieved by set- ting the temperature rise/water flow per the guidelines in the installation instructions. If the hardness of the water exceeds the maximum level of 25 grains per gal- lon special measures must be taken to adjust flow and temperature rise. Water should be softened to a hard- ness level no lower than 5 grains per gallon. Water softened as low as 0 to 1 grain per gallon may be under-saturated with respect to calcium carbonate resulting in water that is aggressive and corrosive.

pH of Water

pH is a measure of relative acidity, neutrality or alka- linity. Dissolved minerals and gases affect water’s pH. The pH scale ranges from 0 to 14. Water with a pH of

7.0is considered neutral. Water with a pH lower than 7 is considered acidic. Water with a pH higher than 7 is considered alkaline. A neutral pH (around 7) is desir- able for most potable water applications. Corrosion damage and water heater failures resulting from water pH levels of lower than 6 or higher than 8 are non-war- rantable. The ideal pH range for water used in a storage tank or a copper water heater system is 7.2 to

Total Dissolved Solids

Total dissolved solids (TDS) is the measure of all min- erals and solids that are dissolved in the water. The

concentration of total dissolved solids is usually ex- pressed in parts per million (ppm) as measured in a water sample. Water with a high TDS concentration will greatly accelerate lime and scale formation in the hot water system. Most high TDS concentrations will precipitate out of the water when heated. This can generate a scale accumulation on the heat transfer surface that will greatly reduce the service life of a water heater. This scale accumulation can also impede adequate flow of water and may totally block the water passages in the tubes of the heat exchang- er. A heat exchanger that is damaged or blocked by lime/scale accumulation must be replaced. Failure of a water heater due to lime scale build up on the heating surface is non-warrantable. The manufacturer of the water heater has no control of the water quality, espe- cially the TDS levels in your system. Total dissolved solids in excess of 2,500 ppm will accelerate lime and scale formation in the heat exchanger. Heat exchang- er failure due to total dissolved solids in excess of 2,500 ppm is a non-warrantable condition. Raypak offers basic temperature guidelines for operation of a potable water heater on normal to moderate levels of hardness and solids but levels of hardness and total dissolved solids beyond normal limits for operation will require special setup and operation.

NOTE: Failure of a heat exchanger due to lime scale build-up on the heating surface, low pH or other chemical imbalance is non-warrantable.

Recommended Level(s)	Fiberglass Pools	Fiberglass Spas	Other Pool and Spa
			Types
Water Temperature	68-88°F (20-31°C)	89-104°F (31-40°C)	68-104°F (20-40°C)
pH	7.3-7.4	7.3-7.4	7.6-7.8
Total Alkalinity (ppm)	120-150	120-150	80-120
Calcium Hardness (ppm)	200-300	150-200	200-400
Salt (ppm)	3000 Maximum	3000 Maximum	3000 Maximum
Free Chlorine (ppm)*	2-3	2-3	2-3
Total Dissolved Solids	1500 Maximum**	1500 Maximum**	1500 Maximum**
(ppm)
*Free Chlorine MUST NOT EXCEED 5 ppm!
**In salt water chlorinated pools, the total TDS can be as high as 4500ppm

NOTE: The allowable concentrations of salt and of the Total Dissolved Solids are lower for the Hi Delta than for a typical residential pool heater, due to the higher water temperatures at which a Hi Delta operates.

Table J: Water Chemistry

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