Common use of CONTROL OF ALGAE Clause in Contracts

CONTROL OF ALGAE. The aim of algae treatment is to take measures to prevent undue proliferation rather than to eradicate existing growths. If algae are allowed to develop more or less unrestricted drastic action may become necessary. Always remember that an ounce of prevention is worth a pound of cure. Where algae has been allowed to gain a foothold it may become necessary to drain the pool so that the sides can be scraped down and the algae destroyed by spraying with a 5% solution of copper sulphate or a 10ppm chlorine solution. To keep any algae in check it is suggested that the water in the pool should be given a shock dose of about 10ppm of chlorine once every month. Copper sulphate can also be used to control algae. Where only isolated areas of algae are noted a bag attached to a rope and containing copper sulphate can be dripped into the pool onto the algae and allowed to stand for several hours. Copper sulphate has the following disadvantages: 1. Could result in bathers’ hair turning a shade of green. 2. Cannot be economically removed from the water. 3. A concentration of 5 ppm will impart a metallic taste to the water. Generally it has been found that chlorine in concentrations of 10ppm is the best method of controlling algae. If a pool has become infested with algae the following procedure is recommended:- a. When all bathing has finished for the day close down the circulating plant. b. Mix sufficient chlorine yielding compound with water in a drum or container to allow the solids to settle to the bottom, decant the clear liquid and add it to the pool water. The amount of chlorine yielding compound needed would depend upon its available chlorine content. To have the required effect on the algae it will be necessary to dose the water between 5 and 10ppm of free chlorine. As a guide, a pool with a capacity of 750kl would require 10kg of 70% available chlorine and a pool of capacity 300kl would require 4kg of 70% available chlorine compound to give 5ppm of free chlorine. c. Dose the decanted liquid as close as possible to the algae growths. In this regard it is suggested that a hose be used to syphon off the liquid. The outlet end of the hose could be fixed to a rod or pole so that it may be maneuvered under water to where algae is growing. d. After allowing about 1 hour of undisturbed contact between the super-chlorinated water and the algae, restart the circulation plant. e. Adjust the chlorinator to feed chlorine into the pool at the highest practical rate. This will ensure that a high chlorine content will be maintained for a long period. f. Adjust the alkalinity feed rate to counter the extra chlorine dosage. g. Allow the plant to run in this manner overnight. h. Next morning: Close down the chlorinator until the free chlorine in the pool is reduced to about 2ppm, then restart the chlorinator and run it to maintain a free chlorine reading of not less than 0.4ppm. The pool should be kept clear of bathers until the free chlorine is in the vicinity of 2ppm. Brush down the algae growths on the walls with a stiff brush, then suction clean the pool.

CONTROL OF ALGAE. The aim of algae treatment is to take measures to prevent undue proliferation rather than to eradicate existing growths. If algae are allowed to develop more or less unrestricted drastic action may become necessary. Always remember that an ounce of prevention is worth a pound of cure. Where algae has been allowed to gain a foothold it may become necessary to drain the pool so that the sides can be scraped down and the algae destroyed by spraying with a 5% solution of copper sulphate or a 10ppm chlorine solution. To keep any algae in check it is suggested that the water in the pool should be given a shock dose of about 10ppm of chlorine once every month. Copper sulphate can also be used to control algae. Where only isolated areas of algae are noted a bag attached to a rope and containing copper sulphate can be dripped into the pool onto the algae and allowed to stand for several hours. Copper sulphate has the following disadvantages: 1. Could result in bathers’ bathers hair turning a shade of green. 2. Cannot be economically removed from the water. 3. A concentration of 5 ppm will impart a metallic taste to the water. Generally it has been found that chlorine in concentrations of 10ppm is the best method of controlling algae. If a pool has become infested with algae the following procedure is recommended:- a. When all bathing has finished for the day close down the circulating plant. b. Mix sufficient chlorine yielding compound with water in a drum or container to allow the solids to settle to the bottom, decant the clear liquid and add it to the pool water. The amount of chlorine yielding compound needed would depend upon its available chlorine content. To have the required effect on the algae it will be necessary to dose the water between 5 and 10ppm of free chlorine. As a guide, a pool with a capacity of 750kl would require 10kg of 70% available chlorine and a pool of capacity 300kl would require 4kg of 70% available chlorine compound to give 5ppm of free chlorine. c. Dose the decanted liquid as close as possible to the algae growths. In this regard it is suggested that a hose be used to syphon off the liquid. The outlet end of the hose could be fixed to a rod or pole so that it may be maneuvered manoeuvred under water to where the algae is growing. d. After allowing about 1 hour of undisturbed contact between the super-chlorinated water and the algae, restart the circulation plant. e. Adjust the chlorinator to feed chlorine into the pool at the highest practical rate. This will ensure that a high chlorine content will be maintained for a long period. f. Adjust the alkalinity feed rate to counter the extra chlorine dosage. g. Allow the plant to run in this manner overnight. h. Next morning: Close down the chlorinator until the free chlorine in the pool is reduced to about 2ppm, then restart the chlorinator and run it to maintain a free chlorine reading of not less than 0.4ppm. The pool should be kept clear of bathers until the free chlorine is in the vicinity of 2ppm. Brush down the algae growths on the walls with a stiff brush, then suction clean the pool.

CONTROL OF ALGAE. The aim of algae treatment is to take measures to prevent undue proliferation rather than to eradicate existing growths. If algae are allowed to develop more or less unrestricted drastic action may become necessary. Always remember that an ounce of prevention is worth a pound of cure. Where algae has been allowed to gain a foothold it may become necessary to drain the pool so that the sides can be scraped down and the algae destroyed by spraying with a 5% solution of copper sulphate or a 10ppm chlorine solution. To keep any algae in check it is suggested that the water in the pool should be given a shock dose of about 10ppm of chlorine once every month. Copper sulphate can also be used to control algae. Where only isolated areas of algae are noted a bag attached to a rope and containing copper sulphate can be dripped into the pool onto the algae and allowed to stand for several hours. Copper sulphate has the following disadvantages: 1. Could result in bathers’ bathers‟ hair turning a shade of green. 2. Cannot be economically removed from the water. 3. A concentration of 5 ppm will impart a metallic taste to the water. Generally it has been found that chlorine in concentrations of 10ppm is the best method of controlling algae. If a pool has become infested with algae the following procedure is recommended:- a. When all bathing has finished for the day close down the circulating plant. b. Mix sufficient chlorine yielding compound with water in a drum or container to allow the solids to settle to the bottom, decant the clear liquid and add it to the pool water. The amount of chlorine yielding compound needed would depend upon its available chlorine content. To have the required effect on the algae it will be necessary to dose the water between 5 and 10ppm of free chlorine. As a guide, a pool with a capacity of 750kl would require 10kg of 70% available chlorine and a pool of capacity 300kl would require 4kg of 70% available chlorine compound to give 5ppm of free chlorine. c. Dose the decanted liquid as close as possible to the algae growths. In this regard it is suggested that a hose be used to syphon off the liquid. The outlet end of the hose could be fixed to a rod or pole so that it may be maneuvered under water to where algae is growing. d. After allowing about 1 hour of undisturbed contact between the super-chlorinated water and the algae, restart the circulation plant. e. Adjust the chlorinator to feed chlorine into the pool at the highest practical rate. This will ensure that a high chlorine content will be maintained for a long period. f. Adjust the alkalinity feed rate to counter the extra chlorine dosage. g. Allow the plant to run in this manner overnight. h. Next morning: Close down the chlorinator until the free chlorine in the pool is reduced to about 2ppm, then restart the chlorinator and run it to maintain a free chlorine reading of not less than 0.4ppm. The pool should be kept clear of bathers until the free chlorine is in the vicinity of 2ppm. Brush down the algae growths on the walls with a stiff brush, then suction clean the pool.