Ok so lemme get into the whole story. I'm growing 10 auto's. It's been about over 72 hours since most of them sprouted and I had them straight under 30W CFL's (2700k, was all I could find). People are telling me that's not enough and I need to switch to HPS. I got a 400W HPS, but I'm afraid not to burn them. Would It be ok to put 5-6 in the tent (2 feet * 3 feet * 5.2) or will that burn them? What distance should be the bulb at? Thanks
I would put it in now around 12-15 inches away and each day move it closer by an inch until you feel comfortable with the difference as we don't know you tents temperature
I always veg under fluorescents. I'm currently using one 26w 5000k spiral per plant and that covers them until they're topped three times, 9" tall and ready for flowering. That said, your plants can grow faster and stay shorter grown under a 400w. Autos especially should benefit from the stronger light. This is only if heat is controlled sufficiently. The seedling phase ends when the single-bladed leaves have grown in, and the 3-bladed leaves are just starting to grow in between them. This is the point where they get transplanted into nutritious soil and are often moved to under stronger lights. It's safest to use CFL's at least until this point imho. Provided the lamp's heat is controlled enough that it isn't an issue, the average 400w HPS needs to be a bare minimum of 10" from the plants at all times. Setting it to 12-13" each day will provide plenty of room for daily growth. Seedlings and clones should be placed at twice the normal distance.
I'd use CFL's, everybody on the forum seems to recommend them at start, the only problem is I only have 30W / plant, and they are 2700k. So, if u were to pick between that and a HPS, would a HPS be better? Thanks man
Thirty watts per plant is more than i use with CFL's in veg. The fluorescents would be fine or the HPS should grow the plants faster. Unless it's an enhanced spectrum bulb, the HPS isn't going to have a better color temperature than your CFL's. The HPS will make more light. That much is better. If the heat is controlled well, it will be better than the fluorescents. However, it's not necessary for vegging. While it'll make the plants ready for flowering sooner, it won't necessarily affect yield at harvest. Whatever you choose, be sure to set up the HPS & all airflow for at least a day before moving the plants in. Monitor the temps and make sure they're safe.
Thanks alot man, was actually just going to move them into the tent. I'll wait till tomorrow. Thanks again
Talking about temperature, I got 2 termometers (normal room ones). They need to be placed at the bottom of the tent right? With the CFL's, the temperature is 2-4 degrees celsius if I place the thermometers at the bottom of the pot, compared to when I place it on top of the pot, just under the light. Where should they be in the tent?
You're kidding? 30W per plant? That will keep the plant alive and kicking, but it won't produce even half-decent results. To veg a good plant, you need an absolute minimum of 100W, and that's pushing it. 50W per plant thereafter is a reasonable start.
I'm talking about real watts and since no one else has described the watts they mentioned as "equivalent," all of the other watts mentioned here also mean real watts, whether intended or not.
Damn, i've been usin three 26 watt cfls, two 15 watt floros, and two 23 watt CFL's to veg (and i only veg indoors for about a week), so am i just wasting power?
More light=faster growth, provided enough food is available. I want to keep vegging growth down to keep the plants, especially the mothers, small. That 26w I use on each plant is only for 8-9" of growth and larger plants would certainly enjoy more light. Up to around three times as much light can be used for stronger growth. The point I was making is that while more light is usually benficial to the plants, it isn't strictly necessary to veg small plants. Since the light is beneficial, you're not just wasting power.