Recently remedied Calcium deficiency; plant has weird yellow splotching all over

As the title says, I was having some random leaves going straight from green to brown and drying up. With some help from this forum, learned I was calcium deficient and added some calmag. Plant perked up and visibly started growing at a faster pace. However, now there is a peculiar yellow, but almost white or light green blotchiness happening all over plant randomly and what is concerning me is that it’s happening on a lot of the new growth.

Can anyone help me diagnose this?

Have you been feeding it? Looks like it could be nutrient burn or if ur lights to close depending on what kind


My money is on nute burn as well. Check your runoff tds/ppm and PH if you can.


I opted for the super soil approach and mixed my own blend of 1/3 Fox Farm Ocean Forest, 1/3 Fox Farm Coco Loco and 1/3 Lava Rock. I also added Down to Earth Organic Vegetable Garden Fertilizer 4-4-4 blended in as per it’s directions, as well as Mycorrhizal Inoculant by Dynomyco again as per it’s directions at the time of blending the soil. Otherwise, I’ve only been watering with distilled water 2-3 times a week and as of the last week or so, added cal-mag and ph’d the water to 6.5ish. Goal has been for the nutes to exist in the soil, so I haven’t added anything to the water except the cal mag recently as mentioned I was advised to do here. Brown leaves seem to have stopped, but yellowing is now happening randomly all over.

Just did a fresh watering today. Runoff ph is 6.5, runoff TDS is 1554ppm and soil ph is 5.0-5.5.

This is the light I’m using ( Phlizon LED Grow Light ) and here is how far the light is above the plant:

Your PH is out. Should be around 6.5, at the very least above 6.0 :sunglasses:

1 Like

I use worm castings like alot and dolomite lime powdered when mixing my super soil. Both of them help stabalize ph. Certain organic matters are acidic so you have to balance it out. And i use to only water distilled but now add a little calmag to it as if its ph perfect tap


Ps also mix enough perlite with any amount of worm castings and ull find out y quick. But worm casting is very worth the use

1 Like

None of the leaves you pictured appear to be new growth. I believe that is residual damage done to the leaves and will never really sort those out. If you have new growth exhibiting trouble it’s likely excess.

I think I’d let her ride for now and monitor.

You’re gonna need more light in flower FYI.


Appreciate the tips! I was aware of this; part of why I chose the Ocean Forest is because it contains the worm castings as well as perlite. :raised_hands:

I ordered some dolomite lime the day I learned my soil was at 5, so I will be top dressing with that tomorrow!

1 Like

I ordered some dolomite lime to help bring the soil up from the 5-5.5 range and will be top dressing with that tomorrow. I thought the yellowing was residual, but it seems to continue to spread and get worse a little more each day so it seems to be progressing. Unless you mean to say that the damage continuing to get worse is residual? When you say new growth, don’t you mean the newest leaves coming out? Some of those I pictured are yellowing.

Right now, I’ve only been running this light with the veg switch on. Even with just that, it turned all the stems purple which I read means the light is a bit too much. But you’re saying turning on the flower switch as well, it won’t be enough light for flower? If so, how did you determine that? If it won’t be enough light, how was it strong enough to “burn” the stems purple?

Thanks again for the help! :slightly_smiling_face:

You haven’t shown me new growth yet so can’t comment.

With the lower end LED’s (this is one), the metric used is 50 watts per square foot. Your light is only 240 watts with a small footprint so you either have to raise it very high to cover 3 plants, thus reducing photons, or concentrate over one plant, thus reducing photons to two plants. With only the veg switch engaged you have only 120 watts which ain’t enough for ONE plant. THAT’s how I determined that. Run both switches on. Purple stems are genetic.

If you put up some newer leaves that are yellowing I’ll take a look.


I genuinely appreciate the time you’re spending to so frequently help me with my posts, thank you! :raised_hands: I’m asking the questions in-depth so I can learn, though. After asking specifically a couple times, I still don’t understand what you mean by “new growth”; I assumed this was a literal term and meant the small, unfolding, newest leaves? But you’re saying what I’m picturing isn’t new growth so I don’t understand and am confused now. Some further clarification so I can understand why I’m wrong in what I’m thinking is new growth would be very helpful!

I’m also further confused about the strength of my LED and the purpling stems. The plant had green stems on natural sunlight up until the moment I put it under this light, the next day the stems were all purple. I googled, and it stated that some strains are genetically purple, but that others can be “burnt” purple if the light is too close or too powerful, etc. The reason I believed this was the case, is because stems which are now shaded underneath the canopy are green, and only stem area that has been exposed to the light is purple. You’re saying this is normal and not light burn? It’s normal to have green and purple stems on the same plant? I’m not looking to question what you’re saying, just asking to learn, because that contradicts what I had read prior in other articles about lighting. This forum was highly recommended to me, so I’m asking so much specifically to learn!

You’ve also prompted another question now, which is what LED light would you recommend, then, for my 4x2 tent with 3 plants?

I turned on the flower switch today. Also, there’s a dozen or so leaves browned again now today, as before. You think this is due to the soil being at 5.5? I top-dressed with dolomite yesterday. (Yes it has blurple on but I color corrected the plant itself in Photoshop. :grin:) Unfortunately, you can see how many of those leaves are lightening and about to brown, as well…

I just want to learn so this can be something I feel in control of and enjoy rather than worrying the plant is going to die or have crap yields because I’m making mistakes. Thanks again! :muscle:

If ur soils at 5.5 then thats more than likey your issues. The roots arnt takin in any nutrients that low. Your problems are pretty minor and can be corrected quite easy

1 Like

Appreciate the perspective! I’m used to raising all the rest of my houseplants, which survive on just watering, no measuring anything and simply drop an occasional leaf here and there lol. Comparatively, this plant seems much more fussy, and I have no personal gauge to even know how serious the problems were. Nice to know you think they are minor! How long should it take to see the soil pH come up after top-dressing with the dolomite lime?

Whats the ph of the water ur using?

Runoff ph is 6.5, runoff TDS is 1554ppm, watering with calmag infused distilled water ph’d to 6.3-6.5.

I am at your service, love to answer questions when I can and hopefully put someone who is able to answer.

Newest emergent growth after problem fixed to see if fix works.

“now shaded underneath the canopy are green, and only stem area that has been exposed to the light is purple”

This is genetic and is simply protecting the stem: not burning. You would likely see many burned leaves before seeing stem burning.

" what LED light would you recommend"

The problem with these lights is the tech used is VERY dated: 10 years? If you look at the performance specs on a properly designed LED fixture with the latest Samsung diodes, it’s like the difference between Fred Flintstone’s car and a new McClaren 1 to 1 haha. There are a number of metrics used to determine efficacy and we’ve found that you only need between 25 and 30 watts per square foot with these. That said; there are other metrics for figuring out how much light to deliver.

I built my own and each fixture peaks at 240 watts. I’ve never run them over 220 watts at peak flower and frankly most of the grow the lights are down around 150 watts. The last SCROG’ed grow I did in that space, RDWC yielded 2 lbs of flower in 4 1/2 months. For a 1.25 grams/watt yield. And I had a plant with poor genetics in the mix which reduced yields.

Horticulture Lighting Group would be my first choice.

“how many of those leaves are lightening and about to brown”

Some of those look like older leaves and will get like that. Eventually they will die or be removed. It does look like a combo of nute burn at some point weeks ago and a moderate calcium def that is also helped by cal mag. Dolomite lime will help too.

1 Like

Thank you again for all the replies and clarification! That all helps me understand more.

Would this be considered new emergent growth that is yellowing, then?

I didn’t even realize this was old tech, I thought LED grow lighting was a newer trend and see so many channels on YouTube using these sorts of lights! I’d much rather use a better one if the comparison is that drastic. Would you suggest running 2 of these for a 200 watt setup?

I’ve top dressed with the dolomite lime, and been watering with cal-mag added to distilled ph’d to 6.5. Trimmed all dead leaves off again today, going to report back in a few more days on that end and see how it’s adapting. Soil has already risen from 5.0-5.5 up to 5.5-6.0.

Thanks again!!!