MarsHydro Mars300 par chart LED Guru | February 15, 2016 | | No Comments About The Author LED Guru An experienced veteran when it comes to growing indoors, hydroponics, and organics. LED Guru shares a massive amount of knowledge about LED growing and how to do it best. Add a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment:*Name:* Email Address:* Website: Save my name, email, and website in this browser for the next time I comment. Δ