Help Beginner Diagnose Problem

[inferius]

First time grower here, looking for some advice. Trying to figure out what deficiency I'm dealing with. I originally thought it was a phosphorus deficiency but it hasn't gotten any better since adding new nutes. 8 weeks from sprout, pH is usually between 6.3-6.7, temp stays from 70-75°F, humidity fluctuates between 40-50%. Was only using Dyna Gro Foliage Pro (936), but got some CalMag and Dyna Gro Bloom (3 12 6) after first symptoms appeared. Could this be a potassium deficiency? The older leaves began yellowing from the tips in, becoming drier until they died. Old leaves also developed some red coloring on the stems, but have only seen this on older fan leaves. Now seeing some leaf curling on smaller leaves around bud sites. What am I dealing with, and how do I solve it? Thanks in advance

 

[The Celt]

Looking at the clawed puffy looking leaves, in the upper right of the first picture, I am going to guess that you are over watering them which causes all sorts of issues, including those you describe.

 

[Emilya Green]

it looks like a potassium deficiency to me, but not because you are not giving enough, because I also see clear signs of toxicity... you are giving too much nitrogen. This could be locking out the potassium, but more likely I think that your problem is pH. You did not identify a certain value that you set you pH to, you gave a range. Instead of adjusting all of your incoming fluids to 6.3 pH, I get the impression you are trying to tell me the pH of your soil... and that is doing this thing all wrong.
Follow the instructions on your nutes and don't give any more than that. Also, be sure to follow up a feeding with a water only watering on the next time, so that you can use up any unused nutes still in the soil. Make sure that every fluid hitting your soil is exactly adjusted to 6.3 pH. It is my belief that these basic changes will fix your problem.

 

[NuttyProfessor]

is this an auto ? , if so you normally switch to bloom week 5/6 , when they stop going north
Over watering is a big maybe too red /purple stems means i cant breath proper ( some have it in their genes )
Need plain ph water if in soil 6.2/6.5 hydro soilless 5.8/ 6.0 get some nitrogen out

 

[inferius]

Thanks for the advice. Here's an update: I've only watered with pH'd water since Wednesday. The leaves are becoming increasingly yellow now, but seem less droopy. This is an autoflower and the pH I gave in the original post was the pH of my water. What should I be doing?

 

[Emilya Green]

you are doing it. Since you followed our advice to clear the soil of unused N with this last watering, you should on the next watering apply the recommended amount of your nutes for this stage of the grow, and this time at the correct pH. That should allow the plant to get the nutrition it needs, and I bet the leaves start greening up now that they can get to the K that is supplied in the nutes

 

[NuttyProfessor]

ok you need to feed lightly 1/2 strength with a good run off out the bottom once dryer , if soil ph 6.2/ 6.3 , soilless 5.8 to 6.0

 

[Koolbudz]

I would probably let soil dry if wet, if its dry I would use calcium and water ph'd to 6.5 and run it through till you see a good amount of runoff... Thats with my nutrients though...Dont know what you should use.

 

[inferius]

Here's another update: I have been alternating between feeding and pH water for each watering. It seems I have some sort of nitrogen deficiency, as my plant keeps getting more yellow and older yellow leaves will dry up and die. There are also some red coloring on some of the newer yellow leaves. Everything has been pHed correctly. The nutes I have are 9 3 6 and 3 12 6. I have stopped giving 9 3 6 because the feeding chart for Dyna Gro says to stop giving it after 4 weeks of flower. I'm now at week 9 of this autoflower, which should be done sometime in the next 2 weeks. Any way to deal with this so late in the game? I appreciate all of your input so far

 

[Emilya Green]

its probably too late at this stage of the game to get everything greened back up, but I do see good green coming back in where it counts, and the buds are finishing out very nicely. I even see fall coloration coming in in some of those fan leaves, signaling that she is near the end. Keep doing what you are doing and you will finish out just fine... next time, armed with your new knowledge, I doubt your plants get to this stage of yellowing ever again.

 

[SoGnotSOG321]

Crazy question, did you check the ph of your water nutrient mixed together? You said you had PHd the water, but you need to check it after adding nutes. If your using tap water, there are dissolved solids to stabilize the water in it and as it sets the ph will rise up as those solids dissolve.
I had a calmag problem in my last grow, one had less soil depth than the others much more peat than I wanted and I had to add some extra at the end. My leaves kinda recovered after a couple weeks and all the dry crispiness stopped and greened up a little.

 

[BeanTownFan420]

Some times plants are older than we think they are and stop drawing nutrients for the senescence.

 

[NuttyProfessor]

Crazy question, did you check the ph of your water nutrient mixed together? You said you had PHd the water, but you need to check it after adding nutes. If your using tap water, there are dissolved solids to stabilize the water in it and as it sets the ph will rise up as those solids dissolve.
I had a calmag problem in my last grow, one had less soil depth than the others much more peat than I wanted and I had to add some extra at the end. My leaves kinda recovered after a couple weeks and all the dry crispiness stopped and greened up a little.

you know i had this problem , my ph was always messing around , once i left the water bubble for 36 hours the ph stayed more stable in my pots after adding my nutrients ,took me a while to work out the problem i always add my nutes stir wait 15 mins stir again ph adjust feed to run off 20%

 

[Newdwc]

Hi! Hoping someone can help me out. This is my second run and I’m learning a lot. I run a current culture 40g rdwc system and use the full line of cyco products. I fill up my res with 40g of R/o water and my water out of the faucet has a PH of 7.2, add my nutes (carefully measuring everything). I then use cyco down and bring my PH to 5.9. I do a full water change in 20 min using the pumps to remove the service of water and add the new mix. After 12 hours my PH is back to 6.4. I’m in the 2nd week of veg and would like to keep the PH between 6.0-6.3. My temps are 68-70c and my water temp is at 68 degrees. Can someone with more knowledge than myself please tell me why my PH is going up so fast and what I can do to fix it. THANKS!!!!