are they worth being free??

[Gumby]

because a few events over the past few weeks I ended up with some lights and balast from a friend who use to grow. I've bought a hps and a mh 400w and have been trying to find a new cheap way to keep some mothers and some veg plants going when they are both filled and need more room. Anyways I got the free stuff and have no info about them, they are mercury vapor lights, one 175 and one 100w lights. Has anyone used them to grow and are they going to be worth even trying to put up?? I mean they are free and will give off light, but i have no idea on there spectrum, heat or anything about them for that matter..

[jadeius]

turn the light on and leave it on for about an hour, go back to it, and put your hand near it, feel the heat, if it's really hot and you're not even touching it, then it's useless

i would just try to grow some other types of plants under it, maybe a tomato and just some flowers, let them sit under the light for a while just to see how they do...you'll see within the first week prolly if they're taking to it well

[Gumby]

is heat the main concern or do they even give off enough light in the right spectrum? I found a 250 hps for $60 so I'll probably end up with that...

[jadeius]

the amount of lumens it gives off and what spectrum are the most important, but you definitely don't want to have a light that gives off a lot of heat, it'll cause stress in the plants...for example, an incandescent bulb puts off too much heat, causes the plants to droop, and doesn't have the right wavelength, more than one problem at a time...

flourescents don't give off that much heat, so you can keep them pretty close to the plants to maximize the amount of light that reaches them...

from my understanding, i think the mh and hps lights may put off a little more heat, but that's just because there's more power in them, and the light is a lot brighter than flourescents, so they don't have to be so close to the plants, and their heat in turn won't fry the plants...

[jadeius]

hps is tried and trusted, just experiment with that other light with some other less important types of plants...if it grows one green plant, it'll grow any other green plant, but not necessarily better or worse...

[fhydro]

I tried mercury light, 180 w, but it gives to much heat and a bad spectrum for the plants. The best are MH, HPS, fluoros. I saw recently a compact light, 130 w of fluro on 70 cm. Good for seedlings and for cuttings.
Fhydro