Newbie light question

I have a 4 x 4 grow tent. I have 400w hps light and (2) 300w leds
Can these lights be used together for the whole cycle? I tried just the leds and they were not thriving.
Someone suggested I add more light.
Plants are in 3rd week since germination and only about 3-4 inches tall
Hoping this is a fix.
Any suggestions?

Yes, you should be able to use the LEDs to enhance and add PAR or Luminous Flux to your 400w HPS, as long as you can control the heat.

LEDs are known for making less heat than other lights, but they will still add some and you need to try and keep your temps a bit below 80*F in your tent.

happy growing,



Also, for seedlings, or very young plants, you should be able to get away with less light, just move the LED light closer, then as they get bigger, raise the lights and add the other LED, then continue the process and add the HPS before bloom.

Plants this young and small shouldn’t need much light at all, again the one 300w led at a somewhat close distance should be plenty.

If the plants aren’t thriving, it likely isn’t the light. You should have plenty. I’d like to know more about the LED, it could be a spectrum issue, but I doubt it.



I agree with not using the hps at this point. The hps will cause your plants to stretch more right now, and the led’s Should have more than enough power at a reasonable distance like @MacGyverStoner said.

Look at the LEDs documentation or ad and find out how many watts they draw from the wall. Manufacturers say 300 watts but really mean 120 or something like that. You need 35-50 watts per square foot for good growth. 600 / 16 is 37.5 watts per square foot but that’s only if “300 watts” is really 300 watts.

Look up the real power and do the math.