I only read how low can I go on a 26.5, didn't see it was for an 8 string lol. With the specs I mentioned this was for a jackson 7 string. You can go as low as you want, but like other responses, it requires thicker strings. I still stand by my previous message. The lower the tuning, I'd prefer to do it on a longer scale. Especially for an 8 string guitar.I'm in G standard with a custom string set. 76 on the Low G. Thats as low as I'd take it. Maybe F with the same gauge. I'd prefer just having a longer scale with even thinner strings.