When should light be first introduced?? Help!!

Yes, you usually tell if it's an HPS or MH type bulb by the appearance of the light...MH is whitish and slightly blue, HPS will make you think of an evening sun...yellowish light. Also you may be able to tell by looking at the um I know it's not the electrode, but the thingy (soooo technical...I'm buzzed, help me fellow light guys!) The shorter electrode is usually a MH bulb and may say Metal whatever on the end, and the longer electrode (where the actual light is emitted) is longer and will usually have sun whatever on it on the end. Hope this helps but if you just have the one, I don't know what you can compare it to...the light (yellow or blue) should give it away tho...

As the others have said, just start the babies out with easy gentle light at a distance for the first few weeks and let them get some roots going and you'll be fine

I've established it's a HPS bulb not knowing if it's 400w or 600w
planning on vegging with cfl for the first time as i'm tight for time and i can only get these bulbs for now
would 6500k do for the first 3 or 4? (18-6) weeks then the hps (12-12) for flowering

Hey there johnb,

6500k is perfect for vegging.:thumbsup:

Going to HPS for flower is good also.

Good luck and good growing.

OM

What OM said...+ you can use the HPS for veggin too, when not using it for flowering...