Another lurker whose first post asks for help

[Teejrocks]

So this is my first grow and I have been lurking and absorbing as much as I can to correct my obvious early mistakes. I was treating my hand watered hydro grow as soil, and my experiment in correcting the ph down to the "proper" hydro range for half the plants resulted in almost instantly fried plants. I tossed the 2 smaller fried girls as one was totally gone and the other went hermie a few days after the burning incident. The sad looking plant in the back left is the one fried after the lower ph that flushing seemed to save, and has no balls showing from the stress and severe pruning as yet either.

The biggest one of the four (front left) is the problem plant, it started showing these spots on the leaves and has become much worse in the last 2 days, as the affected leaves are starting to yellow. It is noticeably worse directly under the lights, but the canopy temperature via IR gun is pretty consistent across the canopy. It seems to only be affecting the newer growth as well, the older growth that hasn't been trimmed is still symptom free. Also worth mentioning, no pests seen with magnification.

Their first night of 12/12 was January 16th, and the girl with the symptoms is the biggest most bud filled of the "soil ph'd" healthy plants. TBH, this was my experimental grow with bagseed while I chose a method and collected equipment for my first "known genetics" grow. I had no expectations of great yields, but now that she is covered in baby buds... I care more and want to save her

Another significant oversight is that I haven't checked my runoff. I was generally watering so there was little runoff and never thought to check until I started troubleshooting. Next water I intend to check the runoff pH to see what's going on there.

From what I've read I'm thinking it may be ca/mg related, but with the symptom's proximity to the light and heat hot spot has me second guessing.

Any opinions/ harsh criticisms from one of you seasoned growers would be greatly appreciated, as I'd love to correct this before my best looking girl suffers too badly.

**Pics to follow shortly

What Strain is it? Unknown
How Many Plants? 4
If in Flowering Stage... How Long? First day of 12/12 was Jan 16th
If Soil... What is in your Mix? What Size Pot? 3 are in Root Farm hydro mix, one in coco. Using felt pots, 3 +1 gallon pots. 2 of each
Size (Wattage) of Light? How Many? 630w CMH (315 x2, in one fixture) ~24" from screen
Is it Air Cooled? Not direct vented fixture(bulbs open to plants), room vented via 6" inline fan, oscillating fan blowing between canopy and lights
Temperature of Room/Cabinet? Night settles at 19-20 c (~68f), day time max 26 c (~78f)
RH of Room/Cabinet? 35-40% (US humidified to about 5% above my house's RH)
PH of Medium or Reservoir? haven't checked runoff, but watering all @ 6.6-6.8 since burning incident
Any Pests? Nope
How Often are you Watering? now going by weight: every couple days for 1 gal pots, 3 or 4 days for the 3 gal pots
Type and Strength of Fertilizers used? Westcoast Blooms organic liquid (fish based) 3-10-12 @ 2/3 suggested dosage, And one application of Plant prod tomato & vegetable (powdered) 15-15-30 @ 50% suggested strength. Gaia Green glacial rock dust for micro nutes.
Size or Square Footage of Room? 4x6 total, growing a roughly 4x4 flower canopy, 7ft ceiling

 

[Teejrocks]

Wide angle shot...


Here's the spotting/yellowing issues:


The one surviving from severe burn after lowering the ph <6.5...


And one of the healthier ones I started from seed on Dec 15th, also in the same root farm substrate, fed identically to the one suffering from the white spotting and yellowing in the soil ph range:


Thanks for your input, and for all of the threads I have been reading to learn all this!

 

[Teejrocks]

Well measuring the runoff was insightful for my rudimentary understanding of nutes/pH/and lockout. Actually shocked at the pH drop across all four plants...

The rescued fried girl (back left) in 3 gal of coco, even after flushing was still way down at 5.1 (watered with 6.65) I actually re calibrated my pH meter after the first test as I thought that it was way to low, but the calibration was good.

The other tortured twig (back right) that got watered with the 6.65 sol'n is in 1 gal of "root farm" had runoff of 5.8. This one never got burned, but was in rough shape due to playing with training techniques.

After seeing the low pH on the runoff from the first 2 plants, I didn't further correct the pH on the second batch, and they were given 6.95 sol'n.

The big momma/ most concerning plant (front left) is in 3 gal of root farm, and the runoff measured in at 6.15. Her stretching has definitely slowed, although I have no clue how much this could be due to the issues she is having.

The last one ended up with runoff at 5.9, and while still looking mostly okay was starting to show the start of discoloration in the lower leaves.

Everything had runoff way lower than I expected, and that poor girl in the back suffered from my unintentional acid attack. I see that I am definitely into ca lockout territory... More concerning is the lack of calcium content listed in any of my nutes on hand meaning there is likely little to no ca available regardless of the pH...

 

[Blew Hiller]

Can't help you because I grow in soil, but you get snaps for the title of your thread