"Vacuum to waste" is a manual-vacuum and pump concept — and robots simply do not work that way, which is mostly a good thing.
What "Vacuum to Waste" Means
With a manual vacuum, you can set the filter valve to waste, sending dirty water and debris straight out of the pool (bypassing the filter) to avoid clogging it during a big cleanup — at the cost of dumping pool water that you then have to refill.
Why Robots Don't Do It
A robotic cleaner is completely independent of your pool's plumbing. It draws water in, traps debris in its own onboard filter, and returns clean water to the pool. There is no waste line involved. The upside: you never lose water or have to refill and rebalance. This self-contained design is central to how pool robots work.
Handling Heavy or Fine Debris
Since everything stays in the robot's filter, matching media to the mess matters. Use a leaf bag for big leaf loads and NanoFilters for fine sand and algae, and rinse the filter between cycles. For a truly green pool you still cannot "vacuum to waste," so treat the water chemically and run repeated cycles — see pool opening. A high-capacity model like the Dolphin Sigma handles big cleanups without a waste line.
