How to fix? Small rust spots? Deficiency?

I’m in my 2-3rd week of flower for my triple xl. I am getting these tiny spots everywhere. It’s not bugs or fungus this plant is touching many others so if it were those two it would of spread plus its directly in front fan it would spread quick. The other plants of the same strain are ok. I have r/o water with advanced nutrients 4ml per liter, 1 ml per liter general hydroponics cal mag, 2ml advanced nutRients big bud, and 3ml in 2.5 gal of southern ag fungicide (hydrogaurd cheaper alternative) plenty aeration in buckets. My ph is always good NEVER gets out range. What is this? I’m guessing calcium or mag deficiency or burn? All foliage affected. This thing will be a nice yield if I can get it back on track.


Are you using advanced nutrients micro,grow, bloom? :thinking:

Curious what lighting you are using?

Take a small piece of paper towel and brush the leaf… if the rust color comes off, its rust fungus… if not, could be calcium or magnesium… off chance could be toxicity…

Since I don’t know anything about hydro, I’m going to tag @Myfriendis410


Yes I am

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I have 3 1000 watt fecidas between 6 plants. It’s actually performed way better than a spider farmer.

Already tried that that’s why I said I don’t think it’s a fungus plus it doesn’t spread to The others it touches and the fan would blow it to every other plant

I reckon calcium,what order do you mix nutrients? :thinking:
May need to give this one a touch more calcium.


Are you monitoring Vpd? Have you tested the par/ppfd those light put out. If they get too much light pressure and the Vpd Is out of line you can start to see some odd def like manganese. My plants grown in soil withmy 645 luxx pro led at 100 percent caused a very similar looking issue. I did not know what the prob was so all of my attempts to fix the problem made it worse. The next run I made sure my Vpd stayed in the green throughout the entire run and they raged the entire time. Here are the three charts I use. One is for clones/seedling one for veg and one for flower. If you can automate the tent to maintain this you will have your mind blown.

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This is how mine started. Eventually every single fan leaf died. Plants flowered but it was boof. Trashed it and now I’m about to harvest some of the best looking cannabis I have ever grown. Wish I new about dli and Vpd and all this yrs ago!


The other plants of the same strain are OK?

Was from a previous run. Eventually all the plants got these these spots. If I would have got my lights and Vpd in check early I think they may have grown out of the issue. I was convinced it was a fungus. At the time I had no idea what Vpd was and how important that is. Too low humidity too high of temp and too much light was my recipe for that disaster


That looked like it would have been phosphorous. The spots are more purple-ish in color. That deficiency usually manisfests itself because of ph lockout. A good liquid bone meal should have fixed it.


Def had a major lockout. These pics are from the very beginning before it got really bad. These plants looked dead at the end of flower. The lockout was caused my improper Vpd and light intensity for sure. I was simply pushing those plants way too hard. I was so stumped because my soil is loaded with all the amendments you could ever want. I thought maybe there wasn’t enough nutrients in my soil so as every other beginner does I started adding more nutrients and just compounded my lockout problem even more I think. At the time my parameters were 1000-1200 par. 90 degree temps and 30 percent Rh and that is a recipe for disaster. Some of these new powerful LEDs run at full power push out far too many photons for the plant to handle if all the environmental factors are not perfect. It’s going to need to take up a lot more nutrients to be able to deal with all that light and in small containers with VPD pressure out of line the plant is not going to be able to keep up. Eventually the stress will cause lockout and in my case all plants hermied.


Well I had phosphorus deficiency with a very weak light (before I bought a big girl light) and all parameters were good. just had to add liquid bone meal and it fixed it right up. I agree though, I tell everyone that you need to check the ph of your soil before you chase anything (nutes, lights, vdp, etc)


In my experience growing in living soil pH is a non-issue. I can’t remember the last time I checked pH or run off ppm. As long as your soil is healthy and you have the proper microbial and fungal colonies the soil will do its job and buffering the water to exactly what the plant needs to be able to take up nutrients when it needs it. Testing for pH in soil is a phenomenon that seems to be a crossover from hydroponic style growing where pH is absolutely something that must be maintained and manipulated by the grower. Soil growers like us don’t have Do any of those things. Properly amended soil doesn’t need /Synthetic SALT based nutrients. so there should never be a concern of over feeding and in turn getting salt buildup which is what will cause massive fluctuations in the soil pH. It is true though that if a person is overfeeding in soil they could get the pH way out of whack causing a lockout. But assuming that the soil is properly taken care of and healthy ph is of no concern to us. The difference in my case that may not apply to everybody as the fact that I grow in very large 20 gallon containers which allows me not to have to worry about feeding as I know there is enough food in those containers to get me all the way to the end with maybe a very light top dressing at the beginning of flower. True living soil growing with organic Amendments is where this applies and container size is a big factor two that needs to be considered. If somebody is growing in an inert media like Coco for example then testing runoff ppm and pH is something that needs to be done to determine when it’s time to feed and also to ensure that the plant can take up the nutrients in the hydroponic solution. The buffering capability of soil microbes is amazing. And true living soil you could literally put any water you want with a pH range between five and nine and not have any problems assuming that the water is not loaded with garbage from a city municipal Water supply. I agree with you that some bonemeal for a minor phosphorus deficiency caught early corrects the issue within a few days in my experience and is exactly what I would do when The determination is made as to the cause of the phosphorus deficiency. If the cause of the phosphorus deficiency is due to environmental factors being out of line which is not allowing the plant to properly take up nutrients that are already available in the soil then adding additional phosphorus is only going to further cause me problems. And in my case the problem was not lack of phosphorus and my soil. The problem was my vapor pressure deficit, DLI,Rh and temps were all wrong which caused my plant not to be able to properly take nutrients. I was never able to fully determine if the deficiency I had was related to calcium phosphorus or possibly manganese but one thing is sure I definitely had a lockout caused by environmental factors not limitations in my living soil. So what I would add to your comment is this. In living soil in particular the vapor pressure deficit is the place to start assuming that your soil has all the proper amendments and is not In fact depleted. If you know your environmental factors are correct then it would be more logical to assume that the soil is lacking the nutrient and then you would want to add it.

Wow! That’s awesome! And you’ve e learned so much in just a couple of grows! I like it LOL

I now mostly grow outdoors in 45-55 gallon containers or straight in the raised garden bed and the bottom isn’t lined so the roots can go dee into natural soil. I still had to amend a
couple of them that were in the 45 gallon pots and I still too dressed with worm castings and microbes. Also smashed up bananas to give the worms a little extra treat.

I agree that with natural and living soil I didn’t need to amend hardly at all… but there was still cause to do so.


Sorry this thing said I commented to much for new account had to wait for 20 hrs lol. So I do micro, grow, bloom, cal mag, big bud, then southern ag. In that order that’s what I’m guessing I’m not a newbie but not an expert lol. It’s weird I added extra and new grown foliage seemed effected.

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I always add cal mag then micro grow bloom

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My vpd is normally 1.28-1.33 thank god for ac infinity auto tents n app lo. I did think possibly mn deficiency to. Also I measure it in lux that’s at 51,000 I’ve gone to 68,000 before no problem with most strains