Is Fish Sh!t a microbe?

Actually both products are excellent but are not the same thing. Recharge contains bacillum and fungi along with kelp, amino acids and molasses to feed the microbes and is used as an inoculant to provide a high number of beneficial fungi and bacillum to fight off any anaerobics. Plants really like recharge. I usually use up until flower. Fishsh*t does contain nutrients and has beneficial NPK value as a fertilizer. There are microbes in Fishsh*t, but I would consider your source as they differ in both the microrganisms available and NPK availability. Usually fishsh*t has a NPK value around 2-3-1. If your source is your aquarium, siphon off enough off your gravel to use immediately as fishsh*t goes anaerobic quickly. I use both recharge and Neptune's Harvest organic Fish and Seaweed Fertilizer that also contains kelp. Good luck!

Yeah it contains microbes. As far as I remember being told you add it to your nutrient solution rather than charging your medium with it. It provides microbes and food for existing microbes in the soil.

Yes its for root growth