Of course hydration is the key to both of these supplements. Just remember one thing. Creatine is usually used for bulking, and ECA is used for fat burning. They do tend to counteract each other.

Consider this - If you want to take both take the creatine on weight training days. Take the ECA on cardio days. If you're training with weights and cardio on the same days decide which cycle you are in. Bulking or cutting?

Here's some information I copied from a search:
"Products like Vanadyl Sulfate and Chromium Picolinate are insulin mimickers that may help increase the absorption of Creatine. We have had a lot of positive feedback regarding the use of Vanadyl with Creatine.

There are a couple of other little known inexpensive substances which may offer much in the way of increased Creatine absorption. Buchu, Fenugreek, Gymnema Sylvestre and Goldenseal are herbs which help prevent rapid drops in blood sugar and help stabilize blood sugar levels as well. There is some evidence that taking any one of these herbs along with Creatine and grape juice or Kool-Aid may further help insulin drive more glucose and Creatine into the muscle cells."

ZMA is fine just don't take it with calcium, and take it 30 to 60 minutes before bed. There's a post on ZMAS pm currently running on this board.