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Algae Control
Posted by steve, in Chemical & Water TreatmentAlgae Control
What Causes Algae
Algae come from spores, which can be picked up through wind, rain, contaminated swimwear and pool equipment. When the conditions are right an algae bloom can happen rapidly, within 24 hours. The conditions that can invite algae growth are, out of balance water, warm temperatures, sunlight, poor filtration and circulation and the presence of nitrates or carbon dioxide in the water.
Algae are a living aquatic creature, which grows best on sunny days, where it can utilise the suns energy and carbon dioxide to photosynthesise.
The reason algae are no good for swimming pools is that they can cloudy or colour the water, which intern causes you not to be able to see the bottom of the pool causing depth perception making it dangerous for diving and rescue attempts. Green algae can also harbour pathogens such as E-coli bacteria.
Algae will also clog filtration systems, which will cost in the long term. Algae also have a demand for chlorine there for using up your sanitizer when should be working on other contaminants.
Types of Algae
There are over 21,000 strands of algae.
Green Algae
Green algae are the most common of all the algae types. You would most likely have a problem with Green Algae after hazy conditions or poor circulation. This form will float suspended in the water or will cling to the walls. Green Algae are unpleasant to look at and can harbour bacteria.
Yellow Algae
Is mostly common on the shady half of the pool, and where there is bad flow or circulation. This form of algae will appear as spots on pool surfaces normally around pool fittings and steps.
Black Algae
This is the worst kind that you can get, and once you have it is very hard to remove due to roots that are hard to penetrate. The best way to deal with this strand is to drain the pool and acid wash the walls and pressure wash.
How to prevent
The best way is for continued sanitizing and controlled PH, along side with regular Shock treatment and Algaecides. It is also important for regular brushing and vacuuming of the pool, as dirt is a good strong hold for algae to start up.
How to KILL Algae?
First off, balance your water, paying particular attention to pH. Secondly, check your filter system is working effectively and clean if necessary. Adjust valving for optimum circulation and allow it to run 24 hours a day until the pool clears. Turn on automatic cleaners to help stir things up. Backwash as necessary.
For suspended green algae, shock the pool…hard. Put in as much Chlorine Shock as it takes to turn the pool a cloudy, bluish/gray color. Brush the walls and floors towards the main drain. Backwash the filter when the pressure gauge indicates the need. Using a flocculent may be a good choice if the pool is extremely “swampy”. If you cannot see the bottom of the pool, and it is filled with leaves and debris, it may be wise to drain the pool, acid wash and refill it.
After the chlorine level has come down below 5 ppm, add an algaecide and brush the pool again. When it all settles, vacuum the pool (to waste, if possible). Check and rebalance the pool water if necessary.
For algae which is not suspended, but only clinging to the walls, follow the same advice above, first shock with brushing, then add an algaecide, brush again, vacuum to waste (preferred) or vacuum and then backwash the filter. Use of a steel bristled brush is recommended for algae on plaster pools (use nylon brushes on vinyl).
For black algae, the brushing part is very important. You must tear through the protective layers so the chemicals can destroy the plant from the inside out. Pumice stones work well to knock off the heads of black algae. (Don’t forget to vacuum them up later, and backwash them out of the filter ASAP). Also effective on the black algae nodules is sprinkling granular trichlor over the spots (of course if they’re on the wall this is next to impossible). Rubbing the spots on the walls with a trichlor tablet or stick can also be effective to knock off the heads and get trichlor directly to the roots. Follow up with a dose of algicide.
If algae has been an ongoing problem in your pool for several years, you may do well to drain the pool. Many years of algae builds up dead algae cells and lots of other solids in the water that contribute to its rejuvenation. Acid washing and/or pressure washing is preferable once drained, to kill the roots of the algae embedded in the plaster. NEXT: change the sand if you have a sand filter. Sand should be changed every 5-7 yrs, and cartridge filters should have new elements every 1-2 years. A well functioning filter will prevent algae.
Please give us a call or send an e-mail if you would like any more information on this or any other pool related subject
