Yellowish Spots on Leaf Margins and Burnt Tips

Ex lux 25.000x0.015=375par think you count wrong or something.

That sounds… confusing. Right thread?

@Bubbelkush, you may be referencing my other post where I show my measurements.

Without a PAR meter the best I can do is estimate the PPFD for my lighting setup. I have been slowly banging on my lighting measurements for some time now. Problem is going from LUX to PPFD is not a straight forward conversion. LUX is a measurement of the luminosity function, or a measure of how bright humans perceive a light source. It is centered around 555nm wavelength and tappers to nothing at 400 & 700nm, so it mostly a measure of green light.

Plants see differently. They don’t really need green light which is why LEDs, at least; peak towards both ends of the PAR spectrum. Deep blues and reds. So LUX is almost an inverse of what our plants want.

I have found a set of equations that do work in theory converting LUX to PPFD but only if you know the spectral power distribution (SPD) of your light source. I have been playing around with these equations and based on my lights I came up with a multiplier of about .017 which is not far off from the .015 you quoted. I don’t completely trust it yet. A LUX meter is just not designed to measure the entire PAR spectrum and errors can creep up at either end of it where the deep blue & reds are filtered out.

At some point I will get this PPFD thing all figured out, and hopefully without dropping $500 on a meter.

Mother of all blooms I believe

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for lack of any other deciding factors I am gonna try and find that… I just like the name. mother of all buds.


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Yee they are very expenciv par meters.
Think that x0.015 is close and its running in 3x3 480w try to race lux every week flower to get grams of my 480w but ends in canopy in 30k lux and that is like 35ich % on dimmer have lot more to offer but can not find way use light full way in that space.

Yee its a trip up and down

30inch all time use dimmer

Hahaha sounds like me when selecting strains.

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When flushing for salts specifically, I have real good luck doing more of a flood table approach. What I mean (phd water) is I flood a bucket (or garbage can depending on your container size) right up to an inch of the soil line. Go smoke a bowl and walk the dog. Then pour it off and let it dry out. Let it soak for 45min-1 hour. Like soak and hold for a laundry stain.
You can usually get the desired flush this way in just 1 good soak and rinse. It has worked well for me.

I have since switched to organic living soil, but back in the day I used me some salts. If I knew then what I know now I would float some microbes in there too. While soak rinsing the pots in the bucket. A pinch of great white, or what ever you like to use. Mycos, recharge etc.