You bought a tank, a filter, a heater, aeration, lights, a timer, some chemicals and fish, but your water's clouding up and your fish are surfaceing, so you guess something has to happen to keep them from dying. Here are my steps to recommend, expediency first, convenience second, expense third, and difficulty fourth:
If you are thinking that tiny crustaceans reproducing quickly will solve your greenwater problem, then guess again. All they can do is what fish do (albeit faster): eat phytoplankton. They might be entertaining by themselves in the way of live food and fast reproduction under good conditions. Under the right conditions (no bubble bars, unless contained), they may cause faster precipitation of nutrients (faster silt build-up). By the way, silt is a useful ingredient in potting soil. It is like sedimentary black dirt and a precursor to clay.
Want to know a good way to gayj when you're fish hav had enough light? Find a small tank, perhaps your wash bucket. Put some water from your aquarium in it. Shine a light on it, twenty-four hours a day for up to a week. If it begins to look too turbid to be inhabitable, then you hav no chemistry to analyze. You aren't removing enough nutrients. Stop getting more fish, because you need more plants before you can put this thing in a window.
My airstones are on half of a day, from five in morning to quitting time for bankers. My light is on from eleven until eleven. This gives me a warning. If my fish begin surfacing, then it's time to find out why or (rather than waste time, because that means something is wrong with my water) put some overtime on air-stones (my timers hav an override for on) and start watering trees, even if it's winter.
I don't like mentioning step four, because it's hard on some plants. As long as you will change your water over, it won't hurt to use algicide once, but if you really hav to use it, then you waited too long to turn off your light, so it isn't a weapon to keep using after you've learned when to off your light, which is long before your fish surface. It does nothing permanent about ammonia build-up, so you should watch those levels if you use algicide.
If you missed anything important in this article, it is that plants can let you put more fish in your aquarium. They eat nitrate. Nothing says ignorant fish keeper (or carp keeper) like fake plants. Nothing says experienced fish keeper than one that lets plants get established for a month before fish go in a tank. They eat ammonia. They close the cycle of nitrogen with tissue that can be easily removed (sometimes, even tubers). A culture in your filter might remove fertilizer from water in time, but it's hard to know how much time. If they don't sell plants, then shop elsewhere for fish. Nevermind professional fish piss. Get plants that drink it.
This trick, usually reserved for larj ponds is interesting in how it works. Don't use it on green water. Under some conditions (warm water, which is typical on the inside, since many fish are tropical) it can make cloudy water even cloudier.
When I started using this, my moss culture changed. It was of a variety that could cling to needle-leaf and feather leaf plants and become something of a parasite for light. It would even settle on my echinodorus. After I introduced Barley Straw pellets, I was able to make precipitate from my illuminated filter float. Barley straw pellets are filter jam.
Barley straw with a careful dose, is a good trick for keeping water clear. The bits of straw decompose very slowly, perhaps at a rate near peat moss or oak bark (two ways to acidify water), making any filter into a fungus (substrate for lichen) within a month.