Can 600HPS work with every kind of ballast?

Hi I have a little question . Some time ago I bought a 400HPS. It has been 4 grows since that time. I heard that I schould exchange the bulb for new one. I thought it would be a nice idea to upgrade it to 600HPS. do you think I could use it with my old ballast that served well under 400HPS ?

You will need a new ballast rated for 600w.

Good friend of mine works as a electricity handy-man and according to him I can use a 250w ballast with my 400HPS. He said that ballast is just ballast I thought that it would be neccessary to buy a new one . My old ballast is broken and he gave me his which worked with 250HPS. So now I have his ballast ( from 250HPS) with my lamp 400HPS. It works.... but does the lamp have the same power then? any ideas?

No. Don't spread this around but you can use any wattage up to the ballast wattage.I'm talking about magnetic ballasts here. Like a 400 on a 600w ballast but you cannot use any more or you will start a fire..... I'm guessing your friend is young and just trying to sound like he knows what he is talking about. Bottom line use the bulb the ballast is for and don't be that guy that burnt down his house.