When is it ok to use my HPS 400??

i was wondering if anyone could tell me what size my plants should be ready to use hps. And when they are how far should i have them away from them. i have a 400 hps hotilux bulb. Thanks for any help. here is a picture of em there about a week old.

I started using my 150 HPS right from the start. I would suggest you do the same. Extra light never hurt anything.

snyder007 said:

I started using my 150 HPS right from the start. I would suggest you do the same. Extra light never hurt anything.

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Like he said.. Now would be good. You should be about 3 ft away, thats on average make shure you aren't close enough to burn them. Maybe a little farther at first since for the first few weeks they are setting up the root base and don't need quit as much light.

you already have your answer.
1. use it now (maybe get a mh conversion bulb so you can use it in your hps socket and ballast..)
2. be sure to keep it far away (3-4') from your plants for now as they are small. let them grow to the light. ventilation is important!

your plants don't need much light for the first two weeks. I use frlor or cfl for the first 4 weeks then change over to the 400w mh for veg or stay with the big cfl's. I use the hps for flower only. IMO its a waste of poewr/money to use the hps for veg. The ct is much lower with the hps then the mh. you can get cfl's in high and low ct.

thanks i will do this but keep far away i have a hortilix bulb it has the blue spectrum in it as well.