1st experiment with too much light

I have a Goldleaf that I’m growing in a 3x3x8 tent. Before I found out about this site, I too purchased a burple. Trying to make amends to the god of lights, I purchased an HLG 280, which by all accounts, should be fine for a 3x3 tent. But me being me, I was sad having bought that 270 actual watt burple, so I decided to use them both. 540 watts of LED goodness. Since I was ordering from HLG I decided to try one of their 60 watt red supplement bars, might as well stick that in the 3x3 for an even 600 watts.

Everything went well until the forth week of flowering when what I believe is a calcium deficiency started. Apparently all that LED goodness comes at the cost of increase in nutrients. I turned off the grow switch on the burple, reduced the brightness of the quantum board, and turned off the supplemental light bar. Then I started feeding it extra cal-mag and foliar spray with calcium in it.

So what happened? The deficiency shows up throughout the canopy.

Started with discoloring of leaves. Then the buds stopped growing. Seems like I’ve stopped the progression with extra calcium.

I’m going to my grow store and buying just calcium, give it a week and then turn on all 600 watts to see what happens. The question remains, how much light is too much light, and can you compensate with feedings?

As a side note, the burple is in the back left, the Hlg QB in front and supplemental bar along right side. The back and left sides appear to grow slightly better then the rest. The supplemental bar hasn’t done anything that I can tell and this is the second grow I’ve used it on.

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What kind of medium are you using? What’s your input and output pH and EC/ppm? If you’re in week 4 or beyond they should actually start focusing on putting on weight versus stretching. From what I was able to zoom in and check out theres a lil something going on but its not terrible. But details about medium and feedings etc will help us and others offer guidance.

Specifics, open forest in 10 gallon fabric pot. Did almost zero feeding until flower stage where i followed fox farms schedule plus open sesame and have fed it four times in five weeks. Previous to feeding I used other fox farms products to feed the soil like Kangaroots, Microb brew and boomerang. I’ve also fed it bembe once.

I checked runoff while giving it an extra dose of cal-mag. a couple days ago. PH in, 6.7, pH out 6.4, ppm in, 880, ppm out, 3180.

The flowering was going great but stalled and hasn’t progressed much in ten days. I’m almost through week five of flower. I’m not disappointed or anything, might have if it was my only grow, but I have 8 plants outside that will finish in October plus a cabinet of jars from a fun year of growing and three more seedlings that I just started this week. I wanted to see what would happen when you pushed it, now I know. Now I want to know if I can correct the deficiency and turn the lights back up to 600 watts and push the plant to giving me lots of big, smooth smoking, buds, or a stick with a bunch of crumbs falling off.

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One thing I’ve come across with stronger leds is the plants requiring more magnesium, especially in flower with fox farms nutes. So I make sure to add Epsom salts to my water weekly come flower time.


How much Epsom salts per gallon?

Sounds like high dose cal-mag might be useful with lots of lights.

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Cal mag never touched my issue. Epsom is just magnesium and sulpher which also helps with terps. I use 1tbsp per gallon once a week.


@Bobbydigital, I just learned some thing new again :grin: Good info. As I come across the same issue here every once in a while. :+1: