Deepin’ peats remarks are exactly to the point. Moina is a very good and potentially fast growing food for Paros of nearly each age (from very small to adult), but they need more attention than e.g. Daphnia. You cannot culture them for months in the same water. But there are different methods possible.
I tell you mine: I kept them in small shallow vessels of about one or two liters each with some (but not much) artificial light and fed with yeast. No aeration; it’s contraproductive. I had at least three or four such vessels at the same time. (I never tried bigger and deeper vessels with success, but I know it’s possible, too). Kept this way they are very productive but very instable too. They need nearly daily care (= food supply). If you are absent for three or more days the culture is at the edge of death if not fed regularly. Feeding by algae results in a slightly minimized reproduction but makes the culture a bit more stable, although not very much. The necessity of starting new cultures is a constant task; I did that every week or ten days with the oldest vessel. I did not clean the vessel completely fed but reduced the free floating debris only. With this method I had a constant high production and could feed all my Paros in more than thirty small (12 liter) tanks, including growing young of many species.
But longer absence or neglect of the constant changes of water/of vessels will definitely result in a catastrophe. The method is good for high production but there is no stability for longer periods of neglect. This is quite different than with Daphnia which need much less attention if kept in larger vessels even with irregular food supply and a better oxygen content than is necessary for Moina. Therefore, Deepin’ peat is fully right in pointing out the need for water change and the need for continuous beginning with new cultures. This is indispensable with Moina. If you manage to find a habit suitable to your presence and awareness, Moina is an ideal food for Paros over many years. If you don’t, it’s a nuisance since it will die out soon.