I think I'd start out with sterilized plants and sterilized everything, i.e. bleach treat the works. In fact, I'm doing this massive program now, three to five years into some tanks. Somewhere along the line I introduced a particularly nasty from of red algae, which I believe is a form of staghorn and also a very thick, green, choking type of hair algae which I think is claph. or oodeo-whatever.
Now, I am not talking here about the soft, brown and green snot algae which comes along with almost every body of water one initiates as an aquatic zone. Those minor annoyances come floating in on airborn spores and then go away with proper nutrient management and the standard plant tank protocols. No, I'm talking about some real serious pests here which I've probably imported from all over the wide, wide world with my many aquatic plant trades. These red algae do not float through the air and are passed on only through direct water to water contact. The only treatment for any type of these Red, pest algae one has as far as I'm concerned is to bleach absolutly everything and quarentine anything, and I mean anything new from then on -- plant, fish, even rocks and wood.
I personally intend to do as Paul Kromholz suggests and closely examine each new plant in a white dishpan under good lighting with a big magnifying glass. Depending on what I discover, the plant may get just a mild, 2 minute safety treatment in a 19 to 1 mix of 5% bleach and water, or as much as five to seven minutes for some anubias and narrow leaf Java fern I know that look as if they might be related to ZZ Top.
Some find this sort of philosophy a bit extreme, but I'll bet in reality they just haven't run into one of these monsters (yet). I've heard some people claim that these algaes evolved in the Asian plant nurseries to take advantage of the exact same conditions many of us like to provide our plants with - high light, high nutrient levels and CO2. If you really have one of these beasts you can try to nutrient manage the situation all you want. I have and it aint happening.
As a matter of fact, I've personally gotten to the point with my aquatic chemistry skills where I can dial in whatever proportion of nutrients (or lack of nuttrients) anyone would care to suggest as a management strategy, and have in fact done so in many extended instances to no avail. Hey, once you have the proper (good) test kits and have determined the nutrient consumption rates on each of your tanks through their use in conjunction with the nutrient calculator -- it's just not that mysterious or hard to do. Algae's still there anyway.
I don't want it managed into the background -- I want it gone forever