Shade, leaves and organic load
Large shade trees keep yards cooler, but they also drop leaves, seeds and flowers into the water continually. As that material breaks down it consumes chlorine and can leave stains on the pool surface. Removing debris before it sinks and brushing walls and steps every week are the main defenses.
Shaded pools also get less sunlight, which can make algae more likely in corners and along steps that see little circulation, so we give those areas extra attention when brushing.

