I look after a friend's property (holiday home), basic maintenance and the swimming pool, when they are not in residence.
The swimming pool is lined with tiny mosaic tiles - a blooming nuisance to clean (not my choice at all!). Earlier in the summer a few tiles started to fall off underwater. Then tiny little roots started appearing in clumps. There were no plants in the garden nearer than 5m. Long story short within 3 months the pool was in such bad condition the owners decided to have the tiles removed and go with fibreglass instead.
So, with the Pool company in starting their work I went in for the day with my Majorero heavy work helper and we started digging around the outside of the pool terrace to see what we could find.
The culprit was a Yucca tree that was about 8m from the end of the pool!
It took the 2 of us all day to cut the tree down, chop out the main roots and then pull up as many of the smaller roots as possible that went all over the garden! And then get rid of it all. Lots of cuts and scratches along the way despite long protective gloves and trousers.
Be careful what you plant in sight of a pool!