I know this is a subject that has been kicked around many times but since our population is always growing, I thought this might be a good time to slide this topic in again.
BAT GUANO USE IN CANNABIS GROWING
Found this information that may give you some guidance to using bat guano. There are several types of Guano.
Bat guano comes in different types. The N-P-K ratio of the guano is dependent on what the type of bat it came from and what it’s diet consists of. For instance, Mexican bats eat bugs so their guano is high in nitrogen. While Jamaican bats feed on fruit, so their guano is high in phosphorus. Lets explore some different types of guano and their application.
Mexican Bat Guano (10-2-1). This type of guano is very high nitrogen. This makes it perfect for the vegetative stages of growth. Even when the plant is young it can be fed a dilute mixture if the soil happens to contain very little nutrients. This type of guano can be used throughout the vegetative stage of growth.
Peruvian Seabird Guano (10-10-2) This type of guano is NOT bat guano. It comes from Peruvian seabirds and is very “hot”, meaning it will burn plants very easily if prepared incorrectly or over applied. Not good for flowering due to high nitrogen content.
Jamaican Bat Guano (1-10-0.2) This type of bat guano is high in phosphorus. It is perfect for the early-mid flowering cycle once females are well established. I have also found several types of Jamaican that have no nitrogen at all and I have to say is, that crop was the tastiest crop I have ever grown.
Indonesian Bat Guano (0.5-12-0.2) This type of guano is the ultimate low-nitrogen, high-phosphorus bat guano. It is perfectly suited for the end of the flowering cycle before the final flush. This drops nitrogen levels low to cut growth and signal the autumn harvest as well as provide a huge resource of phosphorus to bulk up buds and add to trichome count.
As you can see, ideally you use Jamaican for early to mid flowering and Indonesian for late flowering. This is the best answer I can come up with. Hope it helps. Good luck on your grow.