Help identifying plant issues

I’m constantly have issues with some sort of deficiency or even possibly a toxicity shortly after they switch to flower (Auto Flowers) . I’m growing in 3 gallon fabric pots starting off with a 50/50 mixture of fox farm happy frog and fox farm ocean forest with the seeds started directly in the soil. Plants always seem happily and healthy all the way through veg. I’m top dressing using Dr. Earth dry amendments and did my first top dressing around week 4 using 1 TBS per gallon of soil (2 TBS 3-9-4 and 1 TBS 4-6-3) and I did another top dressing aroud week 6 using 3 TBS of the 3-9-4. I’m currently on week 7. I’m water using well water when the pots feel light. My well water has TDS around 60 and a ph around 6.3. If I aerate my water the PH rises to 8.0 after degassing the Co2. Not sure if that matters in living soil. I originally though I might be having calcium/mag issue when I started noticing brown little spots on the leaves especially with the low TDS well water so I started watering using 1tsp per gallon of cal mag. I didnt notice much. I’ve also tried adding a tsp of domolite lime to the soil and also adding 1tsp of gypsum powder and 1tsp Epsom salt to a gallon of water when watering to see if that would help. Ph of the soil runoff is around 7 so that seems good. Plants are in pretty ruff shape currently. Any ideas or opinions on what I should try ?

It's a nutrient deficiency, it looks like a nitrogen deficiency to me. I could be wrong though. I haven't grown in a couple of years so I'm a bit out of touch

Sometimes less is more. Fox Farms soil is rich, and your adding amendments too early and then constantly adding more things usually doesn't go well. You say you keep having issues... try side by side one without adding any of those dressings so early as a test.
You shouldn't need to feed an auto until they start blooming in that type of soil. Though I'm not an auto grower. Just my 2 cents.

In flower the requirements of the plant change. I also grow in 50/50 HF OF and topped dressed at week 4 with EWC and fox farms recharge.
For flowering the plant needs more p and k and if you are running LEDs hot upwards of 65-70 lux recommend cal-mag plus at flower specs. I use an organic pour of nutes called foop and it worked just fine until I had a watering misadventure and missed a dry cycle. That's when I developed a calcium deficiency that I am still fighting. It looks a lot like some of the damage to your leaves but I have been treating it for 9 days and it has stopped progressing.



The plant will need an additional source of nutrition in flower. It still needs nitrogen as well. Find a line of flower you like and add cal-mag plus to your nutes at 3-5mk per gallon.
Leaves will not heal. Damage is done.

Jimski said:

In flower the requirements of the plant change. I also grow in 50/50 HF OF and topped dressed at week 4 with EWC and fox farms recharge.
For flowering the plant needs more p and k and if you are running LEDs hot upwards of 65-70 lux recommend cal-mag plus at flower specs. I use an organic pour of nutes called foop and it worked just fine until I had a watering misadventure and missed a dry cycle. That's when I developed a calcium deficiency that I am still fighting. It looks a lot like some of the damage to your leaves but I have been treating it for 9 days and it has stopped progressing.

View attachment 5453600

The plant will need an additional source of nutrition in flower. It still needs nitrogen as well. Find a line of flower you like and add cal-mag plus to your nutes at 3-5mk per gallon.
Leaves will not heal. Damage is done.

Click to expand...

What do you mean by “missed a dry cycle”. Should I be waiting till my pots feel nice and light or will that kill the microbes in living soil?

Arguments abound on this topic. I water till I feel damp at the bottom of my 5 gallon fabric pots. I weigh by feel as these is a big difference between plant and pot and pot with 6 lbs of water in it. I have never waited until any kind of droop.

The fungi and bacterial load both beneficial and not in soil do not die as soon as it is dry. Like just about everything you come across in growing plants the lanes are wide for a grow. As a new grower I read time again how new growers over water stuff.
I also made all my watering mistakes over 30 years of outdoor gardening for food

Those spots are classic nute burn
In both of your situations

I agree it looks like overfeeding too me..

It almost looks a little fungal to me . ..

I think your ph is messing things up. I would recommend watering with pH of 7. Peat potting mixes tend to have an acidic ph, so alkaline water helps keep soil ph neutral. Water ph of 8 is a little high and most likely causing some issues.

I would also clean out all the dead leaf material that you have placed on the top soil. Its best to compost it, then mix it into the soil once its properly broken down.

Next time mix some fish bone meal into the top soil in week 1 of flower, then again in week 4.