'Best way' might vary from the circumstances of one pond to another. On a dinky rockery pool, a harsh mist spray can blast duckweed over to one side where it is easier to net floating plants out. On a larger natural pond, topping the pond up prior to heavy rain storms stands a chance of flushing the bulk of it out of an outflow On a pond with fish, stopping feeding the fish might persuade them to turn on tasty floating plants On a pond that has been devastated by invasive plants, emptying the pond, leaving it to bake in the sun can do a thorough job where neglected plants have become rampant 'Nuking' a pond of legacy problems can be a convenient time to remove surplus plants, debris, to reconsider choosing more appropriate aquatic plants

Dragonfly Larvae will eat smaller fish. Goldfish and Koi are susceptible when young, but get their revenge as adults. I've seen goldfish devour larvae during my spring cleanings. I think Larry is correct about your guppies. Kind of a no win scenario. Add some goldfish and you would no longer see much larvae, but the goldfish would eat the guppies. Dragonflies do eat mosquitoes. They also eat pollinating insects such as bees. Nature requires a balance. The YouTube video below demonstrates what what can happen to small fish. Here is a link that might be useful: Larvae Attack

Tanchot, Do not use the herbicide on your moss! What you got is not a real moss species!!! It is a vascular plant!! It is also called Scotch Moss, Sagina subulata. It is a great plant that works well as a substitute for true mosses because it does not need the humidity or water quality that true mosses need. I do not know if the UV will really do the job. If you had an aquarium then probably but a pool is a very big system and even with uv and filtration you can have problems. Part of the soapy film problem may be caused by soil or wash out off the adjoining area getting into your pool. Of course it is also a sign of a high nitrogen level from decomposition in excess of what can be handled by the pool micro life. You should re-evaluate your filtering system to be sure that what you are using is appropriate for the size of your pool and perhaps get a power suction pump and try to clean out the bottom of the pool. I never had one of these gizmos as I was low-budget so what I would do to fight this problem is stir up the pool with a fish net on a pole so that the bottom debris would be floating around and then turn on a hose full blast and stuff it into the pool and let the water flood out into a lower pool that I used as a sump for the higher one. I always hated the soapy cover and never really knew if it was a prank. One thing I have found is that if you have a plant like Parrots Feather on the surface of a portion of the pool that it tends to eliminate this problem. It looks like you do not have many plants at all. If you need some I can send you some as I have lots and will be composing them if I can't give them to some local nursery to sell! Depending on your zone they will take it down to mid 30s but if you get lower then you will need to take them out and trash them and get more next season as if they die in the pool they can add to your problems! So think about some plants. There are alot of online retailers. Cheers.

SOOO not organic, however, glyphosate will do the trick. That's the active ingredient in Round-Up. The problem with Round-Up isn't what you might think. The problem is that it has a detergent in it, designed to make it "thinner", (less surface tension, a surfactant), and the detergent is poisonous to plants and animals. The glyphosate just stops the photosynthesis cycle- which your fish and turtles are not reliant on. Look up something called Fusillade II (fluazifop-P-butyl), Eraser-AQ (glyphosate), and then a non-detergent type of surfactant like Dyne-Amic.