Question:
My pool was fiberglassed one year ago and is now developing green algae on the sides. It cannot be brushed off and I have been told to reduce the ph to 6.8 and the chlorine to 1 as the carbonate in the chlorine is now clinging to the walls. I always thought that a fiberglass pool was smooth, which makes it difficult for algae to attach to. Is this the correct?
Please, can you let me know the best way to clear green algae, which is now rough, on the sides of a new fiberglass pool.
Answer:
HI – superchlorinating or treating for phosphates will help take care of an algae issue. If you also have scale on the walls of the pool from calcium that is something different altogether. And yes, dropping the pH will help reduce the ability for the pool to scale. I would change out some of your water in case total dissolved solids is also contributing to the scale situation. I would then superchlorinate with liquid chlorine if possible. If you do that and still have green algae I would begin to suspect metals instead, like copper which presents as green and can come from the inside of a pool heater. If you have a water test printout, that would be helpful in diagnosing what is going on in your pool.
Algae can form and cling to any surface, even a smooth one like fiberglass or vinyl.
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