1. Brush all pool surfaces thoroughly with special attention to light rings, ladders, ladder junctions to wall, openings into skimmers, skimmer wells, joints between the gunite and other surfaces with little circulation.

2. Inspect main drain(s). If necessary, remove grates and clean interior surfaces with brush.

3. Add 450 g of calcium hypochlorite per 10,000 litres of water or 850 g of lithium hypochlorite per 10,000 litres of water. NOTE: Be sure to pre-dissolve this material in water at a maximum rate of 2.2 kg of material per 4 litres of water.

4. Check residual after 8 - 10 hours. If the reading is less than 20 ppm bromine or 9 ppm chlorine, the pool should be brushed again. Then add 240 g of calcium hypochlorite per 10,000 litres of water or 450 g of lithium hypochlorite per 10,000 litres of water.

5. Once the residual is still 20 ppm bromine or 9 ppm chlorine 8 - 10 hours after the last chlorine addition, the pool may be neutralized back to the recommended range of 3 - 5 ppm bromine. Follow the directions on manufacturer's label of neutralizing compound.

6. Add 270 mL of a polyquat algaecide such as Back-Up per 10,000 litres of water.

7. On a weekly basis, thoroughly brush pool walls, skimmer openings, skimmer baskets, ladders, ladder/wall junctions, around light rings and any junction lines between the gunite and other surfaces.

8. For the next three weeks following the super shock, add 240 grams of calcium hypochlorite per 10,000 litres of water or 450 g of lithium hypochlorite per 10,000 litres of water. The pool may be neutralized if necessary after 10 hours.

9. After the routine in item 8, shocking should continue on a weekly basis following a thorough brushing. An oxygen-based shock by be used at the rate of 160 g per 10,000 litres of water. If an oxygen based shock is used once per month shock with 240 grams of calcium hypochlorite per 10,000 litres of water or 450 g of lithium hypochlorite per 10,000 litres of water. Do not neutralize for at least 10 hours following addition of chlorine.

The above information is supplied by Bio-Lab and represents its best interpretation of available technical information at the time of preparation. The sole purpose is to supply factual information to Bio-Lab customers. It is not to be taken out of context nor used as support for any other claim not made herein.