T8 Lights Height and Height of Plants

vostok said:

I'm old school and use T8's from post germ to 3rd-4th lateral, my T8's are 4ft long and on a bank with 6 other tubes with a pc fan in the center horizontally to extract any heat ..and just to keep the air moving, I'm choking 3350 lumen each tube and burning 30 watts an hour, but budget 40w ph, as these are old as fuck now, best is I've counterbalanced the whole rack on 2 x8Kg weights at each end, filling some old whisky bottle tubes, with cement ..lol I've been using this system since the early 1980s, even tho I have a shit load of other options I always fall back to this old junky system ,,it cheap fun and highly efficient, after 2-3 weeks in this they are moved to the ASbESTOSpacked 400w Mh, then usually outside to the sun, or to the 600w hps, but I prefer the sun, as much as possible, many many tricks to pick up ...like stripping all the laterals off the lower sections, if you wish to bub under these T8's as the light don't go far, and inprovves air way too,

Always have 75% of your tubes at 2700k and the rest cool whites at 6500k

peace
"V"

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vostok said:

I'm old school and use T8's from post germ to 3rd-4th lateral

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Trippyness said:

how close do you keep your 400 to the plants?

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Sativied said:

With HPS/MH 1cm per 10watt is usually a good starting point. That's 40cm (16inch) for 400watt.

Actually, starting point as in to see if it gets too hot or not. For the first 2 days I raise it with 50% of 'normal'.

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Sativied said:

Those were a very old example and I flowered under 400w hps back then, no MH.

Nowadays that's roughly 2 weeks after germinating. I usually call those first two weeks preveg, and top them too a couple of days after moving them to mh closet. There I use the 400w mh for 1-3 weeks (1 for hydro, more for soil) and then somewhere during transition I switch to 600w hps.

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Sativied said:

As you concluded already in that last sentence, they aren't actually doing well for 3weeks old. I have seedlings under T8 right now which are at asimilar stage but barely a week old. At 3 weeks they will no longer be seedlings but have 4-6 nodes. You ask if you should move the bulb up, while I can't even see it in the picture. Meaning you should probably move it down. There's roughly an inch space between my 3x18w T8 and the plants.

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