Spots on plant leaf

I’m a new grower and I have encountered a problem which I hopefully can resolve before it gets worse. I noticed multiple plants have nutrient burn but then again some don’t. I have s total of ten white widow extreme plants. Some of them reacted to the nutrient burn and some are growing perfect with no burns. But on one of my plants leaves I saw brown spots and was wondering if that has anything to do with the nutrient burn or is it another problem?? I would like a detailed answer, thanks. I have some pics

Also the bottom leaves on this plant are not perking up!!!

For the spots issue, did some of your feed solution splash onto the leaf? This can cause spots such as that.

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I’m most likely sure that I didn’t splash any nutrients on the plants. I’ve read up on signs like this though. They are still seedlings and some could have taken in too much nutrients at one time but I’m still not for sure

In a dwc tub like this appears to be, besides just the strength of the nutrient – which you should be keeping an eye on the EC/TDS/PPM of your nutrient solution – and of course you should also be keeping an eye on your pH. The pH could very well be a factor.

If you give us some more info, like some answers to some of the relevant questions in the support ticket it could give us a better idea of what might be going on.

happy growing,


Thanks Mac was going to post a ticket though I would like to ask for a picture of your roots and did notice the open slot which lets light in which is never good

ILGM Support Ticket:

What is the strain and type
( strain name- White Widow, extreme feminized seeds)
Indoor or Outdoor? Indoor
Size of space (max height- 5ft, length-5ft/width-3ft)

Soil or Hydro? Hydro
Type of Medium used? Rockwool
System type? Hydroponic Supergrow Cabinet
pH? 5.9
Of the soil or medium (root zone/reservoir/run-off) and of the water and/or nutrient mix that is fed to the plant? Tap water then Ph’d to 5.9-6.2

Type and strength of nutrients used? NPK? EC/TDS/PPM levels? Thrive Alive B-1 Green(0-0-1), Sugar Daddy(0-0-0), Root 66(1-1-1), PPM-530

Of what you feed it as well as what is in the water by itself and in the soil/medium (run-off), or reservoir.
Temperature? 80 degrees

Day vs. night temp or highest and lowest temps? Root zone temps? (24 hour light schedule during seedling stage)
Humidity %? 66-80% (Day&Night)

Light system/watts/lumens/FLUX/PAR? Four Sun Blaze 21 T5 High Output Flourescent Lights(24watts), One KIND K3 300 Watt LED Grow Light

Ventilation system? Two Carbon Air Filters Size? N/A CFM? N/A CO2? No AC-No, Humidifier, De-humidifier?No
Number “weeks/days” from into Season, Vegetative Growth or Bloom/flowering? They are 18 days old, 2nd week in hydroponic system

Here’s a picture of the roots of the nutrient burned plant

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Good point @pigSquishy,

Also with what might be in your tap water contributing to these spots, the temp at 80f is possibly a problem. The water in the reservoir needs to be around 72F max, if at all possible in DWC. Warmer water has problems holding enough dissolved oxygen from the aeration and the roots will suffer without better O2 levels in the reservoir.


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Yes I suspect it is your res temps too as Mac stated you can see early signs of root rot The darker brown on some but that also could be staining from your nutrient line that’s a very shallow res so temps and nutrient lvl may both be too high? Are your net pots right in the water? with high temps low oxygen levels and flooded rockwool root rot would be my immediate concern.

The regular tap water ppm is about 224

That is pretty high ppm for tap water. This could certainly be contributing to the problems, iron or other things might be too high. And again, just the water temps and lack of oxygen can also cause nutrient uptake problems at the roots.


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I’ve changed the water, the TDS meter was 224ppm and added less nutrients than recommended “less is more” and the nutrient burn seems to be receding and back to normal. The darker color on the roots is Root 66 I have been putting in the water which causes the water and the roots to change to a brown color. Thanks for the feedback from everyone!!!

But should I cover the empty net cups with aluminum foil or something else so the light will not get in??? The empty net cups seems to be raising my water temps.

You should absolutely cover the empty net pots so the light won’t get in. Light and roots don’t mix. Also it would allow algae to grow, which would compete with your plants for the nutrients in the water, and worse case scenario – grow on the roots and suffocate them contributing to root rot.

Also, you might want to actually increase the amount of aeration, you can almost never have too much. I’d be sure to have the plants more spaced out, they will get dramatically bigger quickly, especially when you have the reservoir tuned in. And you want to make sure there is a good amount of bubbles everywhere, and especially under each of the plants.


Thanks for the response. I will definitely cover the net cups and space my plants out. I’ll come back if I have any other problems👌🏾

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I’ve used aluminum foil to cover the empty net cups