Those jumping, floating insects are springtails, which are commonly found on the surface film of planted aquaria. They eat plant debris. Water mites are denser than water, and sink when not in motion. Some are good swimmers, but others can only crawl. Water mites are often brightly colored, and have no body segmentation.
Springtails are often drab colored, and are distinctly segmented.
Water mites have 8 legs, while springtails have 6.