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1) What are the most common forms of algae found in a pool?
The most common forms of algae found in swimming pools would be Green Algae followed by Black Algae and Mustard Algae. These algae’s can then be separated into two categories, wall clinging and free floating. Wall clinging algae would best be described as an algae that roots into a surface and is more stubborn to remove then free floating algae. Green algae can be described as both free floating and wall clinging as you can find green algae floating through the swimming pool water or attached to the pool surface, where Black Algae is a wall clinging algae. Mustard Algae can sometimes be mistaken for simple dirt and brushes away but will reappear in the same area very quickly.

2) How does each algae become present in a pool?
Poorly sanitised pool water and poor filtration and circulation are the main reason swimming pools end up with an algae bloom. The most common cause for all algae to form is due to poorly circulated areas known as ‘dead spots’ in the swimming pool. These could be areas such as behind pool lights or capped off solar previsions. The poor water flow allows the algae to start to develop and infest the swimming pool water. 

Another component of an algae bloom could come from phosphates. Phosphates are nutrients essential to the survival and growth of all living matter including algae. The removal of phosphate from swimming pool water will prevent the growth of algae. Phosphate can be introduced into swimming pools by several means including:
• Water run-off from lawns and gardens
• Fertilizer over spray / over-drift
• Rain
• Dust
• Cleaning solutions
• Swimmers (body fluids / phosphate based body soap/ swimming costumes (washed in phosphate containing detergents)
• Decomposing organic matter (leaves etc.)

The higher the phosphate level the faster the algae growth, leading to higher chlorine consumption and increasing water quality problems. To ensure algae free swimming pool water, phosphate levels should be maintained below 100 ppb. Phosphate levels cannot be accurately measured while algae is present in the water as a large portion of the phosphate will be bound up in the algae. Therefore, it is important to first kill the algae using an effective algaecide such as IQ Maintenance Algaecide, IQ Polymax or IQ Metal Free Algaecide. The phosphates can then be removed from the pool water with the use of IQ Nil Phos.

3) What are the effects of each form of algae? (on pool water, structure, swimmer etc)
Algae can effect all aspects of a swimming pool from the pool water, structure and the swimmer. Presence of algae would normally indicate insufficient sanitiser levels making the pool unsafe for the swimmer plus the obvious issue of having an unsightly swimming pool in the backyard. Secondly, algae can have a variant effect on the pool surface, depending on what type of algae is present and what the pool surface is. The longer any algae is present in pool water the harder it is to kill off and remove as it has now had time to take hold and plant it’s roots. If it is a wall clinging form of algae the roots can remain embedded into the surface and leave a stain, which can be treated using IQ Stain Remover.

4) How do you treat each form of algae?
Different forms of algae can require different treatments and our industry has adopted various methods. However, what is widely agreed upon is that algae should be treated quickly. This will ensure blooms do not suddenly occur and it will prevent the algae from reproducing, which can typically happen at a rapid rate. Algaecides and chlorines are synergistic; they complement each other’s actions making the end result more efficient.

The use of these two forms of product can be accepted as an efficient method of treatment. It is important to understand that algae spores are characterised by forming a wax type of layer around them, which prevents them from being attacked. Chlorine is quite effective in oxidising or burning this layer to kill the algae spore. However, we really need to have chlorine available to kill bacteria, so the use of an algaecide such as IQ Polymax or IQ Metal Free Algaecide is very desirable in the overall effort to kill any algae presence. In treating algae, it is important to brush the walls and floor to breakdown the bond that the algae has with the pool surface. This will also allow the chlorine and algaecide to work effectively. From this point, you would need to increase the chlorine level by using a high concentrate chlorine like IQ Ezi Chlor and adding a strong algaecide such as IQ PolyMax. Whilst adding these products, the filtration system should be operating to allow for adequate circulation. Once the algae has been totally eliminated the phosphate level may be accurately measured using a photometer test kit or a laboratory grade test kit such as the IQ Phosphate Test Kit.

5) How do you prevent algae from occurring?
Algae free and safe water can best be maintained by introducing the following procedures:
1) Remove all organic material from pool water (empty skimmer and pump baskets daily and vacuum pool).
2) Ensure balanced water is maintained.
3) Maintain adequate levels of sanitizer (IQ shock and Swim).
4) Use a Maintenance Algaecide to keep algae at bay by dosing the pool with IQ Maintenance Algaecide.
5) Regularly test and remove any phosphates (IQ Nil-Phos).
6) Conduct a shock treatment to continually remove Chloramines (Combined Chlorine) (IQ Shock and Swim).

Remember that chemicals are only part of the pool system, and it is important to maintain the pool filtration and circulation system.