I live in San Antonio, Texas and have a couple of ponds (~2000 and 300 gallons in-ground) that get a little more sun than that. i keep Madagascar cichlids which happen to like our summer weather (winter is a different story). The ponds get direct light most of the day, consequently they are fairly green. I do use, however, aquatic plants to control nutrients- the key to prevent algae blooms that may kill your fish is not overstocking (which I don't adhere to- you know do as I say not as I do). Using barley straw (If I remember correctly) clarifies the water better than UV sterilizer can (believe me, I tried). I don't mind a little of green, I get lost of zooplancton to support my fry- which unlike African cichlids- are not vegetarian.
Good luck-