Cutting

I have three plants growing in a semi secure location and i cant have my plants growing too tall, i need to know if cutting the top of the plant to keep the hight down will hurt or kill the plant. Any advice would be helpful

Topping is fine and it will help some to not let the plant get too tall. By topping you will get two main colas instead of one.
Topping Marijuana- Topping a plant refers to cutting off the top shoot(s) of cannabis plants. You can pinch, clip or snip off the tallest shoots or the freshest shoots. Cut the branch stem just below the last fully developed node,. The plant starts developing branches at the remaining nodes. This is a good techniques to keep a plant short and bushy. Or you can develop many top colas instead of just one. Don't top a plant more than twice and never top when it is in the flowering stage