An alternative:
This year I have battled several outbreaks of nucience algae - the worst was the dinoflaggellets. I went through all the usual procedures and had some progress, but my tank was not anywhere near to the level of appearance I wanted it. I offer the suggestion below - NOTE: it worked for me, and it can cause severe problems if not done right.
Basically, the N and P are in your tank and are used up immediately when available by the algae. My tank always had perfect/near perfect levels of N and P, but obviously my algae did not read my test kit results What I found out was: bateria are even more aggresive at taking up N and P than the algae; however, bateria also needs carbon. Some people use vodka (alcohol) to provide the carbon, I used regular table sugar instead. It took about 4 days before the bacteria population took and my skimmer went nuts. Basically, the bacteria population exploded and my skimmer took the bacteria (with their N and P) out of my tank. In about a week and a half, hair algae had turned white and was falling off. My rocks looked a bit fuzzy, and it took a full month before things settled down. My sand has been snow white every since.
I have a 240 gallon system, and dosed a tablespoon per day. This seemed to be about right.
The biggest problem with going this route is that bateria, in addition to N, P, and C, also need oxygen. If you put too much carbon in the tank, no only will it look like the tank is doing its initial cycle (cloudy water) but it can also starve your tank's inhabitants of oxygen - in other words: a total tank die off.
I never got the cloudy water, and my tank suffered no losses what so ever, but if you read online, some people did. Also, if the N, or the P, get used up, it will limit the bateria, and hense you will not clean out the tank of all the unwanted chemicals.
Also, you need a good skimmer to make this work: if you do not skim the bateria out of the tank, you have accomplished nothing, but then, if you go BB, you also need a very good skimmer.
Just to make sure everyone reading this understands: it worked for me, but it has wiped out other people's tanks when not dosed properly.