Light Settings for Indoor Soil Grow

New to soil grow, here’s what I’ve got: WW auto and I have questions; I want to start the germinated seed w/a 1" tail in its forever home consisting of the following

5gall black bucket w/5 3/8" holes on bottom and 3 on the sides
5lb jade rock for succulents for drainage
12qt FFOF
HLG 350R Diablo light
clear plastic cup to dome the germed seed

  1. What settings to use for this powerful light? currently at 16" hi and on #3 setting (#1 doesn’t illuminate)
  2. FFOF says not to add nutes for 90 days. Can I use any/all of the nutes (diluted at first) I have from my attempt at DWC? cal mag, hydrogard, gen hydro floragrow and amor si’
1 Like

Hola @Dorf

Set the light at the distance from the canopy listed on hlgs website, then set the light to match these DLI settings depending on your grow week stage.

From hlg 350r

DLI = Daily Light Integral

Chart for autos

It is generally 4 to 6 weeks for a plant to deplete nutes from FFOF. I’m not sure why they would say 90 days.

Use a PPM meter and measure the runoff from your pot. Begin feeding when runoff dips below ~1,000 PPM.

Floragrow contains nitrogen. You also need to feed Florabloom and Flora micro for phosphorus, potassium, copper, iron, boron,…

Fabric bags are much better. It is easier to capture runoff and fabric bags breathe very well, which is necessary for good root health.

1 Like

Great info thank you all! What I’m looking for is

  1. dimmer switch setting for germed (unsprouted) seedlings and
  2. the height from the top of the soil as seedlings have not sprouted as yet. I see its 24" for vege and 15" for flower but nothing on seedlings?
  3. I’m on a 16/8 light schedule for seedlings, 18/6 for vege and 12/12 for flower (if I ever get there)
1 Like

@midwestguy I have 17qt tote under the bucket to capture runoff. thanks I didn’t know I needed to check ppm in the runoff

Unfortunately, you’ll have to get a light meter whether a quantum meter or lux meter… There is also an app call Photone… Many on here use it.

Someone on here may have documented the dimmer dli per notch on the dimmer but not sure.

Thanks for the info! Sadly my phone is not capable of using the photone app. Can anyone recommend an inexpensive light meter (DLI?) for LED full spectrum light?

1 Like


Cheapest quantum meter I can find. Works great. Accurate.

You can also use a lux meter… However, converting to ppfd is not as straight forward as lux and ppfd are different measurements of different things about light.

"Both PPFD and Lux are units used to measure the intensity of light. Whereas Lux is universally used to measure and compare the brightness of visible light, PPFD is referring to the amount of light suitable for active photosynthesis of plants. "

Good info, thank you! I found this one (same company) that appears to be the same as your link.

I am using a LED full spec. My questions is: I have a light chart for the entire growth., but it’s measured in DLI. How do I convert PPFD/LUX to DLI? Is there a light chart for PPFD/LUX?

1 Like

@Dorf On hlgs website there’s a DLI calculator.

Sorry…When I bought my quantum sensor it was the only one available on Amazon at the time.

Here’s a couple I would be interested in buying now:

The last one… If accurate… Seems pretty cool… Otherwise the one with the wand would be my first replacement kit… It also has option to track vpd.

1 Like

Thanks you for your input! I went with the $74 VBR-100 It measures LUX/LC and PPFD/DLI with a selectable hours and types of light. Between the DLI light AF /age DLI chart my 2-1/2 week WW looks healthy and happy. Thank you!

1 Like

@Dorf Please let me know how it works for you.

Mine is getting old, was planning on getting one of those.