which matters: watts or lumens?

which is more important to the plants? if it is lumens, will bunches of cfls be equivalent to a mh or hps?

its lumens thats important

you will need a lot of cfl's to match the amount of lumens a HID light produces

1 400 watt MH light is around 40000 lumens
1 23watt cfl is around 1000 lumens

My understanding is that cfl and hps/mh are better for different parts of the grow. I'm also pretty new to all of this, though.

From what I understand cfl should be used in the early stages of your plant, the vegi stage, to encourage root and stem growth. cfl produce less heat and can be much closer to the plants without harming them than hps/mh. That is the stage where your lights should be on 16/8 to mimic the natural rooting stage produced by the sun.

hps light is much hotter and gives the plants what they need during the flowering and 'budding' stages of your crops. Cutting the light down to 12/12 makes the plant go in to flowering season to reproduce, and that's when the hps that feeds flowering growth should come in.

This is just my relatively newb understanding of the differences in cfl and hps from what I've gathered on this forum. Hope it helps. ><

This could help most folks re:lighting??
lumen watts info

Watts in inportant too. You don't want to set your pad on fire.

Lumens is the light that the plants see. Lumens are most important but watts are important too. The more light the more lumens. My bud uses a dual spectrum set-up with a 400w MH and a 600w HPS in the same hood. It produce way more crystals then the 400w Hps he used to use or my 600w Hps. So both are important.

lumens is a measure of light. watts is a measure of energy used. either can be used to determine light requirements if you know the conversion factor between the two for that type of light.

for instance, hps lamps have about 100 lumens per watt while fluorescents are closer to 60 lumens per watt.

lights in the stores are always quoted in watts, sometimes also in lumens.

thanks. also, should i buy full spectrum if they're available? (vs. cool/warm white)

i am not a fluorescent expert - check
https://www.rollitup.org/general-marijuana-growing/723-things-know-about-lighting.html

mrfishy thanks for the link, it clarified some stuff. you too desertrat.

You're quite welcome. Forum learning works great, but sometimes it helps to look just a little further into such and such. Now you know forever.

Just FWIW. CFL lights put out MORE heat than a comparable HPS light, but since no one is making a 400 watt CFL it is hard to get a direct comparison. If it takes forty 23 watt cfl bulbs to put out the same lumens as a 400W HPS, then you will see how hot they get and how much more efficient the HPS is. The cfl bulb itself stays cool, but the ballast in the base gets hot.

For vegging plants and seedlings a MH HID is more preferable over a CFL or fluorescent light. probably the biggest reason people use CFL is because it does a good job at vegging and costs very little. not to mention you don't need a special ballast or anything to use them. IN actual growth you will see a MH outdo a fluoro.

HPS can do veg and is the best light to use for flowering bar none. If there was one BEST light to get, it would have to be the HPS. A MH still does a better vegetative job than HPS though .