If you had mice in your house, how would you respond? Personally, I would try to find and seal up the obvious flaws in the structure through which they gained entrance; I would set a few traps and monitor/service them daily; and I would scrupulously clean up food scraps and make sure that no foodstuffs were accessible to the mice. If the mice can't get in, have no food and are being trapped out...they will soon be gone, or at least under control...and then don't wait until you have another plague of them; keep on top of it.
Or...you could tent the house, vacate and remove all the people, pets and plants, and flood it with deadly poison gas to kill the mice.
I know which course I would, and do, follow.
Algae is the same; outcompete it with plants, tinker with illumination so that your plants have enough but no more, reduce nutrient levels by more frequent and larger water changes, don't overfeed and thus load the tank with unnecessary nutrients, and generally practice good maintenance. Clean and remove algae as it appears, rather than waiting until everything is coated in green. Learn how many hours of light your tank requires for its plants, and then split that illumination into two separate periods, morning and evening, with a lights-off period in between; this step alone can work wonders. If you are going to have plants, then...
have plants! Don't just stick a couple spindly stems in, bite the bullet and buy a good load of plants. The tank will require the same illumination either way, but with lots of plants the algae will need to compete for available nutrients rather than merely overwhelming one or two small plants. Floating plants are often the easiest to grow and not only do they utilize nutrients, but they also shade the tank which helps in the battle as well.
Or...go the lazy route and buy a bottle of some mysterious chemical potion and toss it in; chemotherapy for your aquarium. In this case, you would essentially be hoping to walk that fine line between achieving nothing versus killing everything. Reading the bottle is easy; believing what it says may be a challenge.
Again, I know which route I would choose...but everybody is different, and lots of folks apparently think that the Better Living Through Chemicals approach is the way to go.
Whichever you choose...good luck!
