I would go with EGTA, couple mM you are pretty safe. Also, if you don't want to have to use a chelator, you can simply prepare your medium without calcium.
Thanks for all your help. Since the medium I need that should be without calcium, without glucose, without HEPES, without HCO3-, without phenol red, I can not find one that without all of these reagents. Sigma D5030 medium is much closer, but they contained about 1.8mM Calcium. I will try EGTA chelator. Thanks again for all of your help:-)