If you are talking Acropower, because that's about the dosage recommend, I would start out with less.
I have been using about the 5ml per 20 a couple of times a week now, but when I first started I ended up with Cyano at that dosage. Start low and work your way up. Seems my system needed time to acclimate to the aminos.
That said, the growth on my SPS really took off after using aminos. Just start slow.