I think we may have enough to go on now.
All of us that have responded are suggesting you do maintenance to rectify this issue rather than relying solely on daphnia. There is a problem causing green water, and the cause needs to be addressed. Just adding daphnia, even if they did eat this, is like solving a toothache by taking a handful of Tylenol, it does nothing to fix the issue. Water changes have to be significantly increased, feeding of the fish probably decreased, thorough vacuuming of the substrate during water changes, good cleaning regularly of the filter. The light on for only four hours is not likely the issue, so it has to be the organics feeding the unicellular algae.
The RO Vital [earlier you had typed RQ Vital which is probably why none of us could find it] is increasing the mineral content, in other words, making the water harder. Is there some reason you are using this? What is the GH and pH of your tap water on its own?
All of us that have responded are suggesting you do maintenance to rectify this issue rather than relying solely on daphnia. There is a problem causing green water, and the cause needs to be addressed. Just adding daphnia, even if they did eat this, is like solving a toothache by taking a handful of Tylenol, it does nothing to fix the issue. Water changes have to be significantly increased, feeding of the fish probably decreased, thorough vacuuming of the substrate during water changes, good cleaning regularly of the filter. The light on for only four hours is not likely the issue, so it has to be the organics feeding the unicellular algae.
The RO Vital [earlier you had typed RQ Vital which is probably why none of us could find it] is increasing the mineral content, in other words, making the water harder. Is there some reason you are using this? What is the GH and pH of your tap water on its own?