Is it Safe to run two different spectrums of lighting during Flowering ?

Hey Guys I have 6 flowering ladies (week 3)under a 600w HPS.I was ''told'' by a person at my grow shop which I trust to add my 480w 8 bulb T5 even though they have the blue spectrum veg bulbs.I am just questioning adding the different color while flowering what would you do in this situation ? Id like to add the light because I feel my 600 isnt adequate enough for all 6.Any suggestions or experiences would be awesome.

Go for it - the more usable spectrum the better as long as heat and cost is doable.

As long as they get 12 hours or more of darkness a night, the spectrum of light they get during the day will not affect their flowering schedule.

You can use the extra light if you wish, it should help.

yes I do it

Some T5 side lighting would be awesome and would definately increase your yeilds.

Awesome guys thank you.Heat hasnt been an issue so far thanks to my fans.I wanted to get other opinions on combining a ''Veg" spectrum and flowering HPS.My electric bill went up $64 per month because of my tent and I really didnt see any difference when I was vegging with the T5's so whoo hoo for me LOL Thanks again Im gonna go add those this morning