Can you use this to make mead?

Absolutely. I used this once to make mead and had it at 12% in 24 hours and 15% in 48 hours. It finished around 18% after 4 days. It will blow right through an airlock so make sure you have your fermentation bucket/carboy sitting in something you can clean up easily. I used 3lbs of honey to one gallon of water. You will need to back sweeten your mead if you let it burn through all the sugars which happens fast with this yeast. Turbo yeast is basically a yeast with a good nutrient in to to jump start the process. Keep the room your brewing in between 75 - 80 F for best results. I prefer Lavalin 1118 as it finishes nicely around 19% every time. Also gives the mead a lighter dryer taste. A simple recipe is 1 gal of OJ 3.5 gallons of water and 15 lbs of honey. You'll end up with about 5 gallons of mead which is roughly 27-750ml bottles. Hope this helps. Enjoy.

how many gallons will 243 gram treat, or how many grams per five gallon batch? I dont have a package so I cant reread the instructions carefully.

Thanks for asking. Each package contains 243 grams or 8.6oz and will treat 6.6 US gallons. That is about 37g per gallon. You can also find a detailed picture of the front and back of the package with directions in the Amazon listing if you ever need to refer to it. Thanks!

over half a pound to work only 6 gal of mash? dada yeast is more thrifty isn't it?

DADY yeast has no nutrient. The fermentation on a sugar wash will be more difficult w/o the nutrient. Use Dady on whiskey mashes and not sugar washes.