As you may have heard on social media, the Olympic Diving pool in Rio turned a murky green - seemingly overnight, making it difficult for olympic athletes to swim and compete in.
Tony Azevedo, captain of the US waterpolo team, said he could "barely" open his eyes for the final quarter, after their 6-3 victory over France on Wednesday.
But why did it turn green?
There are many reasons why swimming pools can turn green. Here are our theories:
1. Unbalanced pH level. It is important that pool owners frequently test their pools pH level and adjust accordingly using pH increaser and reducer. If a pools pH level is too low or too high, it can cause chlorine not to work, meaning the water is not being properly sanitised. In turn, this can cause dirt & bacteria to build up that would have otherwise be controlled by chlorine treatment.
2. Lack of shock treatment. As many pool owners know, it is very important to treat a frequently used pool using a high dose of chlorine called 'chlorine shock'. This type of chlorine obliterates all dirt and debris in your pool. Normal chlorine dosage must then resume 24 hours after shock treatment.
3. Lack of algicide. Algicide works by starving your pool water of nitrogen, meaning algae/bacteria cannot thrive. This prevents and inhibits any algae growth in pool water. It may be possible that the pool maintenance team did not use any/enough algicide, meaning algae flourished. You can buy both algicide and longlife algicide here.
4. The sun. Pool owners regularly dose their pools using chlorine to maintain clean water. Chlorine can come in different forms (chlorine granules and chlorine tablets) as well as different types. One type of chlorine that is very popular in sunny countries is stabilised chlorine. Stabilised chlorine is a special type of chlorine that is protected against the UV rays. If standard chlorine was used instead of stabilised chlorine, it is likely that the sun may have broke down any available chlorine in the water making it easy for algae to bloom.
5. Broken or bad filter. It is possible that the Olympic diving pools filter is either not strong enough, or simply broken. This means that the water is not being sucked into the pump, filtered and pushed back into the pool - simply put, the water isn't being cleaned properly. Like a pond, water without movement can go stagnant. Check out our pool filters here.