From the FAQ:
How much Spirulina should be taken?
We suggest 10~ 20 tablets a day for adults, 6~ 10 tablets for children under 12 years old. If you have special requirements for extra nutrients, please consult your chemist or your health practitioner.
You'd better like popping pills if you're going to be taking 20 tablets a day!!!!
20 tabs per day
They absolutely stink. I'm flat out trying to swallow 1.