Ffof soil with trio nutes. Purp Kush auto's. Day 60 from seed. Week 4 of flower I think. Battled heat and humidity but now better. Feed every other watering. Brown spots don't rub off. Used calmag to fix. No deal. Stopped calmag to fix. No deal. Ppm as of now are 1200. pH has been a struggle but finally up to 6. Tap water set out 24 hrs. Any advice welcomed.
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you have to correct pH first and foremost. Then nutrition can be used by the plant.
The CO2 will only work if your light supply is high enough and the light is consumed by a healthy plant. The app mentioned above can help determine how much light you’re supplying. Otherwise, you could be supplying more CO2 than the plant can use.
clip any leaf that it touching the grow medium, is in the shade, is blocking a bud growth site, or is necrotic or so chlorotic that it isn’t functioning properly.
knowledge is easily gained. Asking questions is a great start. Reading books and watching videos are another sources.
the leaves already chlorotic due to pH won’t get better. Only new leaf growth will look better. The damage won’t rub off. At this stage of flower I doubt your going to see much new leaf growth because the plant is in bud production mode.
your total devolved solids (TDS) measured by 1200 ppm shows you have nutrients. …but the plant looks chlorotic/necrotic.
regardless, you need to increase pH to ~6.3 or so to let the plant use the nutrients in the soil and the Ca-Mag you’re providing. It looks like your plant has a lot of nutrition deficiency which I believe is attributed to low pH. Microbes can help allow the plant to use nutrients and buffer the soil into an acceptable pH as well (Recharge and Mammoth P are good but there are others).
soil slurry test
Gather some soil from the test area.
Take the homogeneous sample and add equal parts of soil and distilled or deionized (DI) water in a 1:1 ratio. So, for 25 grams of soil you would add 25 mL of water.
Stir the sample for 5 seconds.
Let it sit for 15 minutes.
Start stirring the sample again after 15 minutes, and take your measurement.
if you’re soil is at 6, pH your dechlorinated water to 7 to get it higher (add baking soda to water). 24 hrs might not be enough to dechlorinate tap water depending on volume, beginning chlorine level, and surface area. Chlorine test strips are avail. I’ve done tests that show it takes me 48 hrs to dechlorinate 2 gal of my tap in a 5 gal Home Depot bucket.
I recommend using Cal-Mag+ up to 2-3 wks before harvest. pH the dechlorinated water after adding Cal-Mag+ Is added and before microbes. pH after microbes added is not required. the sawtooth edges are angled upwards. I think that’s due to light heat issues. If you can duct some AC into the area that would help. Fans and a swamp cooler (evaporation) can help, too. Raising lights a few inches can also help but there a balance to be struck with DLI. Photone is a pretty good iPhone app vs buying a $200-$500 PAR meter.
Daily Light Integral (DLI)
micro Mols per second = PPFD
PPFD * .0036 (3600 (sec in an hour) / 10^6) = Hourly Light Integral (HLI): example: 600 * .0036 = 2.16
HLI * hrs of light per day = DLI: example: 2.16 * 18 = 38.88
Let it drain over and check your PH in the left over water and maybe get a little kit and do a soil samp[le PH easy to do and you will know whats up much better running 1200 is pretty high I never go over 9oo .