Move Light Closer?

[dwyndorf]

Hi again,

 

My bronzewhaler f3 seedlings are now about 6 inches tall with 3-4 sets of leaves and looking great. How close should my 400W hps be to the plants now?

 

Cheers

 

dwyndorf

[Luke Skywalker]

It's mostly related to temperatures. As the light gets closer to the plants, the more energy is passed to it in light, but also in head. HID lights put out a lot of energy.

 

So the answer is, take some time and slowly drop the lamp to about 30cm from the plants, depending on your enclosure, hood, etc etc. You can usually get within 15cms sometimes will excellent ventilation, but usually it's more like 20 or 30 cms away.

 

Slowly drop it day by day to get the plants used to it, hardening them to their new stronger light, and you should be able to find a good level about 30cm away. Some say if you can hold your hand at canopy level and it doesn't feel hot when you take it away after a minute, then your canopies okay.

 

Personally, I use a thermometer, and keep it below 30 if I can.

[F420]

yup, and an easy test is to put your hand an inch above the tip of the plant and make sure it doesnt feel hot, if you would like sitting in that temp then so will the plant.

 

Biggest problem with the little plants is drying them out.

 

Lukes idea of thermometre is good, whats even better is a thermostat switch that makes the fan kick in at 30 deg.

Edited April 19, 2004 by Ferenge420