My experience is that with the smaller AIO this 1.5-2 lbs per gallon, DOESN'T WORK FOR SMALLER AQUARIUMS. My brother and I have identical tanks and he ordered 20 lbs just for his 12 gallon tank. When they arrived, it was way, way, way too, too much! In fact he gave me what you see, we divided up by 10 for me and 10 for him.
He got two hitchhikers, baby small matis and pistol shrimp, he decided to keep both and they are happy with his fish. The Mantis is a tiny purple species, not the peacock but a smaller species like I said.
This is his KPA live rocks he kept, remember this is 10 lbs from the 20 lbs that was ordered. You saw mine already, this is his from January, this year.