Question
Hi Tom;
Thanx for the info.  Question - how do I determine accurately the
light output that my plants are receiving at different distances from
the light?
Thanx again
Peter------------------------
Followup To
Question -
Hi Tom;
I am growing some coleus from seed.  I have a floralight - 3 tier,
each tier with 2- 40 watt agro lights.  I have started the seeds in
a plant holder - the plate like thing that goes under plant pots -
i forget the name.  I am using seed starter soil and the
dimensions are exactly so that I have placed a tempered glass
frying pan lid over the whole thing to keep in the moisture.  The
whole thing is under the lights at a distance of about 14 inches.  
I started about 10-14 days ago and many of the seeds have
germinated with 2 little leaves.  Could you please advise as to
how close to the lights the seedlings should be?  When should I
remove the lid?  How moist should the soil be?  When I first
watered the soil, before putting on the seeds, I used damp-off in
the water.  should I still use damp-off.  I have never tried to
grow seeds before - so fat,  this is neat.
Thanx in advance
Peter
Answer -
Hi Peter,
Thanx for your question.  I too, get a  big kick out of growing plants from seeds.  I've grown
coleus many times before.  I keep my flourescent lights about 8-10 inches above the planting
medium.  If most of the seeds have germinated, remove the lid and let fresh air circulate around
the seedlings.  Keep the soil moist but not soggy.  Coleus likes moisture and doesn't like to dry
out.  Use the damp off for a few days as the seedlings become acclimated and grow larger.  After
that, you shouldn't need it if you have frree flowing circulating air.  Transplant the seedlings into
separate cells or pots when they get their second set of true leaves.  Good luck and have fun!
Tom

Answer
Hi Peter,
I apologize for the delay in answering the following.  Thanx for your followup too!  I haven't pulled up e-mail for a couple of days.  Been kind of busy so sorry again for any inconvenience.

I really don't know how to answer the question of determining the light output at different distances.  There are meters that read light output I know of that are used commercially and in office buildings to ensure the correct amount of light is reaching employees or customers.  I would think these things are expensive.  I think what you really need to know is how much light do your different seedlings need.  Coleus doesn't seem to need as much light as say okra because coleus prefers shade or partial shade for best growth.  Okra is a tough guy who likes heat, sun and lots of moisture.  Okra has a tendency to get leggy (grow spindly and fall over) as it climbs up to reach the light of the flourescents.  Delphiniums get kind of scraggly if started indoors unless the light is right on top of them.  Other seedlings like tomato, pepper, don't get leggy as long as you lower the temperature once they germinate.  Really bright light, such as natural sunlight out in the green house is best for certain types of plants and I'm sure there are websites out there that speak to that.  I've learned by trial and error what gets leggy and what doesn't.  Four O'clocks start out great indoors but get crazy and spindly and although I've been able to transplant a few they are best started out of doors because they climb toward the light so fast and furious.  If this doesn't answer the question let me know and I'll do more research.
thx,
tom