Many automatic pool cleaners not only suck debris off the floor of the pool, but scrub as well. Some can scrub the walls and steps. This is an excellent benefit, especially when your pool is in the shade for some parts of the day. Mould is usually found in the shaded parts before those sunny areas. It is always wise to inspect places such as behind the hand rails and other hardware in the pool which can cast shade onto the pool walls and floor.
However, simply running your hand over the walls below the water line will tell you if mould is starting to propagate before you can see it. The surface of the walls will feel slippery to the touch. It’s essential to get those walls scrubbed down, then shock the pool by adding more chlorine well before you see any black stains.
It’s important to also clean the filters and treat them for mould at the same time, otherwise the spores will remain in them and re-infect the pool after it has been cleaned. It takes some time to clean mould from the pool and it should not be used during this time. To ensure your family doesn’t use the pool, cordon it off with tape and put signs along it.
You’ll need to scrub the spots with a long-handled, stiff brush before applying algaecide to them and leaving overnight. The process needs to be repeated again the next day. By using a pool cleaner, mould may not get the chance to invade your pool.
Black mould is especially difficult to get rid of and even when it is done, it can leave behind unsightly stains. To remove these, place a chlorine tablet and a few small rocks into a sock, tie the top and leave it on top of the stain. If the stain is on the walls, tie a string to the top of the sock and lower it into position, then anchor it by tying the string to a heavy object on the edge of the pool.
Leave in position for as long as the instructions dictate, then scrub the spot once again. This should take care of most stains, but you may need to repeat the treatment for the worst ones. During this time, the pool should not be used, because that will disturb the chlorine from around the stain, making it more diluted before it has a chance to do its job.
Why does mould form? It is usually because the pH balance and chlorine levels have not been properly maintained. If you find it difficult to do this, talk to your pool installer or the person who sells pool cleaning agents. It could be something quite simple that is being left out of the cleaning regime.