Done properly. With the correct amped wire and voltage rating. Correctly insulated. And remembering that the amount drawn from the ballast has to be exactly the amount its giving off. So theoretically you would need 2 500w HPS to do this safely. Theres always that issue that the bulbs and ballast are designed by manufactures to operate each with there own ballast/bulb. Dont do it though, its not worth getting busted over.
THIS is NOT true! You DO NOT have to run the EXACT wattage! That's JUST DUMB! I mean yea, you'll get the most out of it, but ITS NOT NECESSARY!!
My dad is a MASTER ELECTRICIAN and OWNS his own company, I've worked for him on and off my whole life and I completely wired MY 3000 sq ft house on MY OWN! You can tap in another bulb EASILY, using the proper wire and socket of course.... I'm SURE SOMEONE will jump on this and say I'm full of shit, in that case.... Explain THIS!
My two backyard HPS's are a complete kit! It comes with the following: 142w Ballast, 70w Bulb, a Reflector, the plastic cover AND the wiring! ALL of this is a LITTLE 50 bucks per unit...! Doesn't get much Better than THAT! I would assume (well I KNOW) that if Phillips KNEW the ballast and bulb combo would be a fire hazard, they wouldnt make it the WAY ITS BUILT!
I have one in my grow tent now, just the 70w with 500+ watts of cfl in a homemade hood! I'm in the PROCESS of doing EXACTLY what your talking about! tapping me another socket into THE 142W ballast, that way my ballast is capable of using its FULL power! 70+70, do the math... Ill tell you THIS! It DOESN'T EQUAL 142!!!!! LOL!
Each bulb will than be seperated and put into their OWN 6 inch DIY "cooltube" using candle vases and my hood I have NOW! I THEN will have a splitter for the ducting, SO that way air can pull through BOTH bulbs tubes via ONE inline duct fan at the exit of my tent!
Think of a cylinder of glass, think about the vases SHAPE! Got it? K good... Lol!
I will take the vase and cut the BOTTOM off with string, lighter fluid and ice! (YouTube it!) Once I have a perfect OPEN cylinder than I will "rig" me up a VENTED socket holder on one end (so air can pull OVER THE BULB!) & the other end(s) will have my ducting hooked to them (with the inline fan followed close behind, CONSTANTLY drawing cool air over the bulb!) going OUT of the tent... Makes sense huh?! And I'm ALREADY working on it! TWO COOLTUBES PUSHING 140 WATTS OF HPS GREATNESS FOR UNDER FUCKIN 60 BUCKS! 75 TOPS! Can't fuckin beat it bro...
Just loom around until you find how to wire the two bulbs! The ballasts' power DOES NOT MATTER unless you're EXCEEDING IT with a higher wattage bulb(s)!! That's like saying, "hey these two 12 volt batteries won't turn ovet this 24 volt truck!" Uhhh, why NOT!? That's how THEY MAKE MOST 24 VOLT DIESEL'S N SHIT!
Nonetheless, happy growing... You're ballast will be ABSOLUTELY FINE, AS LONG AS YOU WIRE EVERYTHING CORRECTLY!!! 2 bulbs amounting to what your ballast is rated is perfectly fine! Just DON'T GO OVER! AND IF YOU DO, its not a "fire hazzard"?! If ANYTHING the bulb just WON'T put out its FULL POTENTIAL, WORST CASE SCENARIO being that it doesnt have "ENOUGH JUICE" to ignite it at all....
SO JUST BREAK EVEN ON WATTAGE OR UNDER ON THE BULBS... SIMPLE. I dont get on here MUCH because Ive found a "better" site... But when I do the "how to" video, I will be SURE to post it here!!
I dont see why ppl give out misinformation CONSTANTLY! If you DON'T KNOW, then why even ANSWER! ?!?