Lighting for new seedlings advice

i have a 3x3x6’ growing tent. i am currently using a 600w metal halide lamp and i just placed my fermented seeds in dixie cups. is this light too much for new seedlings? i have fans inside to help heat escape and to keep air moving. i do have a small plastic dome that i used in the past but that was before i had a tent and i used a much weaker light a small square pane led that put off no heat. I’m not using that setup now but was wondering if I’m doing right. once transplanted to permanent growing pots I’m using the metal halide for the entire vegetative stage. am i on the right path? i can still use the old setup if necessary. thanks

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New seedlings need to be protected and treated very gently. Keep them in a humidity dome with 100% humidity and slowly harden them off over several weeks, gradually reducing the humidity in the dome until it matches your target humidity for veg.

For light levels, shoot for 100-300 micromoles. Too little and they’ll stretch, too much and they’ll be asked to work too hard. You can use the app in the attached picture with an android phone up roughly measure PAR by knocking the last 2 digits from the reading. 15000 LUX is equal to about 150 PAR. I have compared this app against a calibrated PAR meter and can confirm it works. There are lots of light meter apps, but I can’t guarantee they’ll be accurate.


Light spectrums are a factor too but @devjyarn pretty much summed it up… I’ve been looking into a T5 after I recover from being Santa for my kids lol… for my seedling only tho after that(veg) my quantum board… As a small tent grower I just think hps/mh produce to much heat even when cooled never tried cmh but @devjyarn @hoppiefrog can probably help with that


I use t5s. Power veg full spectrum