Multiple fans for set ups

Can having to many fans harm your plants? I had a heat problem with a CFL PC growcase I bought a year ago and want to make sure I have to much ventilation rather than not enough... unless too much air will really hurt my grow.

Also, how much light is too much light for a grow area? Can a 600 watt light, with say my two or three 6" fans be adequate for a small grow tent?

I just purchased this grow tent and will now buy fans, but wanted to ask everyone else before moving along. Thanks in advance

http://www.amazon.com/Mylar-Reflect...UTF8&qid=1349751331&sr=8-7&keywords=grow+tent

If you have too much air blowing on the plants constantly and not oscillating you can get what is called "Wind Burn", you want to have an intake vent at the bottom of the tent and an exhaust fan at the top drawing the hot air from the lights/tent (preferably an air cooled hood & an inline fan hooked up to ducting) and you want an oscillating fan blowing back and forth over the plants strong enough to move the leaves/stems but not too strong that is stresses the plants. As far as light goes as long as you have your temps/ventilation in check more light= more bud, a 600W HID in an air cooled hood with a 4" or 6" inline fan would be perfect for that tent, with a good enough inline fan you could get away with using a 600W HID an open reflector but I would highly suggest using an air cooled hood, HTG's Euro Reflector is good quality and at a decent price but there are many brands to choose from. Good luck and keep us posted.