One of my plants has these brown spots and yellowing going on. Is this a calcium or magnesium problem?
I flushed 2weeks ago and even started giving it more cal mag but it seems to keep getting worse.
How much calmag are you giving? Also note calmags are 1-0-0/2-0-0. On NPK. Plants use less nitrogen in flower and are easily burned by it. Some use epsom salt in flower instead of calmag. Any other nutrients? Grow medium? Tickets help a lot for better information.
COPY/PASTE the below list into your forum post.
Answer these simple questions the best you can.
If you do not know, or do not use something; Just say so; Or post
NA (non applicable)
-What strain, Seed bank, or bag seed (photo or auto)
-Age of plant/what week of flower
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Pots, Grow beds, Buckets, fabric pots
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system LED, MH/HPS/CMH/Fluorescents, or other
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No
If growing Hydro some additional questions:
-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
-Temperature of reservoir
-TDS of nutrient solution
-Amount of air to solution
Always try to upload a clear picture in white light of any issues you may have to allow the community to assist you.
Add anything else you feel would help us give you a most informed answer should be included. Feel free to elaborate, but short and to the point questions and facts will help us help you in a more efficient manner 
Thanks
3 Likes
Yea,I was giving it 10ml per 2gal but moved it up to 11ml thinking it was a calcium or magnesium problem.
-What strain, ILGM Blue Dream Auto
-Age of plant/4th week of flower
-Method: HP Pro Mix
-Vessels: 5gal fabric pots
-PH 5.8-6.3
-PPM/TDS or EC of nutrient solution if applicable no
-Method used to measure PH/ shitty vivosun ph pen
-Indoor or Outdoor if indoor, size of grow space/ 2x4 tent
-Light system LED, MH/HPS/CMH/Fluorescents, or other/ HLG 260 XL
-Actual wattage draw of lights/ turned up at 75%
-Current Light Schedule/ 24hrs
-Temps; Day, Night/ 79-80
-Humidity; Day, Night/50
-Ventilation system; Yes, No, Size/6"fan
-AC, Humidifier, De-humidifier,/small dehumidifier
-Co2; Yes, No/no
1 Like
I would definitely get a ppm tester. Even the cheap ones work fine, without all the care and frequent calibrations that cheap pH meters require. Just make sure it’s on the scale you want to use. Mine likes to switch to ppb on me, not a cheap one and I knew it before purchase.just didn’t know I’d find it so annoying. One before that was on the 500 scale which most use the 700. Are you feeding only calmag in promix? It’s an inert medium and calmag doesn’t have any pk. Making the spots look more like phosphorus deficient. Just don’t see it often, so I don’t assume it. Most auto growers find at least 4 hours of dark to be very beneficial as well.
3 Likes
Im feeding with fox farm trio at half strength
I’ve not used your medium or nutrients so I’ll tag some people who have or will know better who.
@Myfriendis410 @Docnraq @dbrn32 @PurpNGold74
1 Like
How far away are your lights? The brown spots and yellowing with a good ph (between 6-6.8) can suggest light stress. When using FF trio you will need to supplement with Calmag, it will look like that too if you don’t,
This looks like the culprit but yours is very early. That’s my guess. Using bright LED’s this is likely it.
Also, here is a conversion chart for 500scale to 700scale ppm meters.
@budz is correct, there is nitrogen in Calmag, not all Calmag is the same either. I bought this and it’s 4-0-0
2 Likes
@Myfriendis410 is a ProMix vet.
But those spots look more like a P or K deficiency. See how the leaves are yellowing (kinda like N)?
In flower they eat a ton more. Id up them from half to 3/4 strength. And maybe back to 10 ml of calmag (as @Budz said, that bit of extra N could push u into toxicity range).
1 Like
Im just spitballing myself. Was looking up a few deficiencies and its not as obvs as I thought. I saw yellow with brown spots and immediately thought maybe K.
@Dave (Happy Cake Day btw) can we see a few more affectd areas? Preferably an older shot and a wide view. Along with some closeups of any pullable fan leaf
3 Likes
I’d like to know the TDS numbers going and out but like Purp said you have some defs going on.
First I’d suggest continuing with the cal mag, set your lights back to a 12/12 schedule as the plant will benefit from some down time and that HLG light is pounding it now. This can make plants very C hungry. Leaves damaged will not recover so look to new growth for signs of improvement.
3 Likes
Thanks @PurpNGold74 here’s some more pictures. I’m going to give it some more P and K to see if that helps any.
I’ll test the ppm while im at it.
2 Likes
I think the fellas have you on the right track. Wanted to ask if your ph tester was able to be calibrated? I feel like some of the cheap ones are, and some aren’t. If you can, I would check that it hasn’t floated out of calibration.
2 Likes
Just to clarify. You said ph is 5.8 - 6.3. Is this for feed, runoff, both?
2 Likes
I have been using a cheap ass vivosun ph pen but it wouldn’t keep calibration.
I was calibrating every 2 wks and last week it wouldn’t even calibrate so i tossed it.
Looking to get a blue lab or apera now.
2 Likes
It was for both
Hmm maybe should wait for new pen. I use an Apera PH20. It does not have the replaceable probe but it is good, accurate and fast.
3 Likes
Im getting some ph strips today off my brother to use until i can get a pen. Hopefully i might get it by Tuesday if i order it tonight but who knows since this covid shit has screwed up shipping times.
2 Likes
