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400 or 600 - which would you pick?

Posted by wordwiz ( on
Sun, Jul 4, 10 at 15:25

If my experiments go well (crossing fingers), I hope to grow several (40-80) tomato plants upstairs this winter. I'm trying to decide whether to use 600 watt or 400 watt HID lamps.

Should I go with three 600-watt lamps or four, 400 watts? The former will give we way more lumens (200,000 vs. 152,000) but the cost per lumen is almost the same for both lamps. However, the initial cost difference is significant: four 400-watt systems will cost about $500, three 600-watters about $700. At the same time, growing four plants per 3.5 sq. ft. is going to create a very lush and thick plant canopy. I'm thinking those extra 2133 lumens per s.f. might be worth the extra cost - if each plant produces 3 extra pounds of fruit, I would recoup my costs the first grow.

The heat generated will be about the same and the difference in operating costs will only be about $30 over four months.

Your thoughts?


Follow-Up Postings:

RE: 400 or 600 - which would you pick?

I guess the real choice depends on how much the bulbs, difference between the energy usage and how long you intend to run the rig.

My gut says the 600 watt lights are going to win, more light, costs abit more but I figure its not only the first grow harvest you've got to think about, its ALL of the potential harvests! Which makes me think that the 600w is a winner over the 400w

RE: 400 or 600 - which would you pick?

Hi Mike

Not sure it makes a whole lot of difference. My big decision has always been answered by someone who suggested that if you go with the 600s best use a movable track cause they tend to burn the foliage left within 20" of the plant tops.

My 400 rig has no movable track and I use it within 14" of the top of the plants. I personally think 3 400's is better light dispersion than 2 600s but maybe with movable tracks that is totally bogus. I do like the fact that you can get the plant tops closer to the lights with the 400s but I have no experience with the 600s. I do know that being able to move the lights up and down easily is a must because plants will grow. I thought it wouls be a lot easier to do this without those mechanical track things. A couple of turns on my trailer boat winch and pulley set up does that with ease.

I have always found is a good source but if you find better let me know. I'm not getting a commision here so I can switch in a millisecond.


RE: 400 or 600 - which would you pick?


Hobbylights (that's the store the e-mail address leads to) is very good on bublbs, but htgsupply is cheaper on systems. I can get a 600-watt switchable digital ballast, a very good reflector, cord, socket and MH or HPS bulb for $200. The seem to be nice to deal with.


RE: 400 or 600 - which would you pick?

It's now been two weeks since the plants went into their buckets. I almost feel like I ought to unplug the LED to put it out of its misery. There is simply no competition, both is size and quality of the plants. I'm wondering if I ought to try one or two 105 watt CFL bulbs to see if I can get tighter nodes, then switch to LED once they start flowering.

Here is the page.


Ignore last post!

I got my threads mixed up!


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