If you don’t own a pool then you can stop reading this post here!
However, if you do have a pool and like me, you are having difficulty keeping the grouting clean it may be you are facing the same issue as I am.
A well informed young lady at a pool shop explained it to me very well. Believe it or not, this summer has been colder than normal. Yes, there may have been a few hot days but overall it has been cool for this area. Those cooler but yet sunny conditions were apparently perfect for the growth of black algae in the pool and whilst regular dosing with chlorine controls the growth of green algae, it will not halt the growth of the “black stuff”. Even those 4 in 1 tablets will struggle to keep the black algae under control.
Cleaning the bottom of the pool won’t shift it either, only brushing with a stiff pool brush will remove the algae but even then it will come back within a short space of time because brushing only removes the growth, it does not kill the roots.
The young lady went on to explain that the solution to this dilemma was to treat the pool with a specific algaecide for the job. Most of her clients, who know a thing or two about pools, had been in to buy bottles of black algae treatment this year. She told me the stuff was literally flying off the shelves.
Remember that what you want is an algaecide which is specific for black algae because that is what is making your grouting look dirty. Other algaecides may remove the green variety and shock chlorine will help with that but both will leave the black algae untouched.
There are instructions on the bottle I bought which the lady suggested I should ignore.
The worst affected part of my pool is where it curves from the floor to the walls and that is where she said I should concentrate the solution. She told me to mix about 750 mls of the chemical with roughly 9 parts of water and then pour the mix around just inside the edges of the pool: sprinkling any remaining solution into the middle. I should do this at night when the pool pump is off to allow the chemical to settle to where the algae is growing.
The next morning, I should set the pump running as usual, brush the bottom of the pool to remove the now dead algae along with its roots and finally vacuum the bottom to remove all the sediment.
In persistent cases, it may be necessary to apply a second dose. In fact, the instructions on the bottle suggest that you should dose with a weaker solution at regular intervals to keep the black algae from returning. The instructions also say that is safe to bathe in water that has been treated.
So there you have it, the solution to your problem of dirty grouting lies in a bottle of algaecide which you can get from any decent pool shop.
Since the lady was kind enough to give me a through explanation, I will mention the shop I bought mine from - Emisan Pool Spa located in the commercial centre on the left side of the road which takes you from the coast road (N332) to Iceland in San Fulgencio.
Whilst you are there, stop for a coffee at the German bar/restaurant at the far end inside the centre. For 1.20 you get coffee with a little fairy cake and a small shot of Baileys topped with whipped cream – it makes going to Iceland bearable!