extension cords from digital ballast to power center

searched around but couldnt find any info.

I have my MLC power center plugged into the dryer outlet, the dryer cord is stretched the full 6ft, and mounted.

My new nextgen 1k 240 v digital ballasts only come with 6 ft power cords, and my lampcords are as far as they can go...... i need 5 more feet!!! I just found out 8ft is the longest they make...which is still too short.

Is it safe to run a 14 gauge heavy duty extension cord hooked to each ballast cord to the power center?

I dont see why not,, but would it effect lumens etc???

I would go with it. 5 feet is not very long and you are likely to lose any, but in any case make sure the wire is rated at at least 4.5 amps, and that you will not lose too much with your length.