Is this light burn or nute issue.?

[Gasman5.0]

Soil Grow
1. Are you growing from seed or clones? Seed
2. How old are your plants? They are
26 days into 12/12 cycle period.
3. How tall are your plants? Idk 30”-ish
4. What size containers are they planted in?
5 gallon pots
5. What is your soil mix?
Miracle grow potting soil 25qt with one brick of coco, 8qt. perlite, 4qt. peat moss
6. How often do you water and what type of water do you use?
When soil is dry and the pot is light which right now is every 3~4 days.
7. What is the pH of your water?
5.45 as bottled and I typically water in @ a corrected 6.25 ph after nutes are mixed in.
8. What kind of fertilizer do you use and what is its NPK ratio? Veg cycle I used Miracle-Gro and transitioned into flowering with a mix of MG and FLOWER FUEL and now I’m only using Flower Fuel 1-34-32 @200 ppm with Advanced Nutrients Sensi Cal Mag Xtra @ 5ml per gallon.
9. Do you foliar feed or spray your plants with anything? No
10. What kind of lights do you use and how many watts combined? One 250W Samsung LM301B 3000k/660 NM Quantum Led Grow Light + Meanwell HLG Driver Grow
11. How close are your lights to the plants? 16”
12. What size is your grow space in square feet? room is 4x5x8 100% totally covered in reflective material.
13. What is the temperature and humidity in your grow space?
76*F 38-~45%rh
14. What is the pH of the soil?
Today’s Feed and Today’s runoff
Feed plants 1 and 2 ...275 ppm FF+5ml Cal Mag+ 32 ppm & 29ppm in bottled waters= Feed in
PH 7.01, total 645ppm 1: total 650ppm 2
Feed 3... 7.16Ph plain H2O 84ppm (last runoff 3 days ago had 400ppm more in the runoff than feed in)
Runoff
1:144ppm/5.32Ph
2:124ppm/5.18Ph
3: 334ppm/ 6.09Ph
15. Have you noticed any insect activity in your grow space?
No.. room is a clean and sealed controlled environment with air conditioning.
16. How much experience do you have growing? Noob

Three day’s ago I switched from a Morsen 1000W ( 155w measured) Blupurple too the new 250W Quantum led and I see a slight yellow on a few leafs. I look at my plants a few times a day and never noticed the slight yellow on some of the leaves and it may have been there the whole time and I never seen it under the Blupurple led and now I do see it possibly just from the white led or is the light too close idk... or do I have too much nutrients. I’ve checked my runoff many times and it’s always been in the 5.20~5.40 zone but being it’s in soil I’ve not attempted too try and correct the soil runoff beyond little PH in corrections 6.3~7.0 because the plants looked fairly healthy too me idk if that’s the case are not though. I moved my light up a couple inches too 18” when I noticed the yellow hue on the plant and I’ll move it quite a bit more if this light burn.
Thanks for the help.!

 

[Jimster]

Do you have any idea what the PPM readings are for the outflow? When plants flower they react differently to nutrients, and sometimes high nute levels can create deficiencies later on in growth, since the reaction to make some compounds unavailable can take a while to develop. Too much Phosphorus and Calcium can create issues like this. If your outflow is high, I would cut back on the nutes a little. If the PPMs are low, then a smallish snack would be my recommendation. A little epsom salts should fix any magnesium deficiencies, which is sort of what it looks like is starting... but with a change of lights, that could also influence the leaf issues... especially if there is any UV included now.
It doesn't look like too much light, as I don't see any burning or cupping of the leaves, just the start of some discoloration. FWIW, some plants get yellow fan leaves during flowering. This can be caused by low Nitrogen, but sometimes the plants just do it. Things look pretty good other than the discoloration in the bigger fan leaves.

 

[Gasman5.0]

Do you have any idea what the PPM readings are for the outflow? When plants flower they react differently to nutrients, and sometimes high nute levels can create deficiencies later on in growth, since the reaction to make some compounds unavailable can take a while to develop. Too much Phosphorus and Calcium can create issues like this. If your outflow is high, I would cut back on the nutes a little. If the PPMs are low, then a smallish snack would be my recommendation. A little epsom salts should fix any magnesium deficiencies, which is sort of what it looks like is starting... but with a change of lights, that could also influence the leaf issues... especially if there is any UV included now.
It doesn't look like too much light, as I don't see any burning or cupping of the leaves, just the start of some discoloration. FWIW, some plants get yellow fan leaves during flowering. This can be caused by low Nitrogen, but sometimes the plants just do it. Things look pretty good other than the discoloration in the bigger fan leaves.

I water/ feed them today.Plants 1 and 2 feed @
PH 7.01 for both, total 645ppm in plant 1: total 650ppm plant 2
Feed 3... 7.16Ph plain H2O 84ppm (last feed/water too runoff 3-1/2 days ago had 400ppm more in the runoff than I feed it with.)

Runoff from today’s watering.
1:144ppm/5.32Ph
2:124ppm/5.18Ph
3: 334ppm/ 6.09Ph

My ph runoff has hung in this range the whole grow and the plants look like they do now so..I haven’t added anything too raise the soil ph because the plants look like they are doing okay.

 

[Jimster]

I water/ feed them today.Plants 1 and 2 feed @
PH 7.01 for both, total 645ppm in plant 1: total 650ppm plant 2
Feed 3... 7.16Ph plain H2O 84ppm (last feed/water too runoff 3-1/2 days ago had 400ppm more in the runoff than I feed it with.)

Runoff from today’s watering.
1:144ppm/5.32Ph
2:124ppm/5.18Ph
3: 334ppm/ 6.09Ph

My ph runoff has hung in this range the whole grow and the plants look like they do now so..I haven’t added anything too raise the soil ph because the plants look like they are doing okay.

The Ph is kind of low for my preferences, but if things are doing Ok, then it might be best to leave them alone. I have used wood ashes mixed in with my waterings to slightly bump up the Ph, and it adds nutrients too, just doesn't contain nitrogen but plenty of P and K.

 

[Dr.B]

The Ph is kind of low for my preferences, but if things are doing Ok, then it might be best to leave them alone. I have used wood ashes mixed in with my waterings to slightly bump up the Ph, and it adds nutrients too, just doesn't contain nitrogen but plenty of P and K.

Good for tomatoes too!

 

[Gasman5.0]

The Ph is kind of low for my preferences, but if things are doing Ok, then it might be best to leave them alone. I have used wood ashes mixed in with my waterings to slightly bump up the Ph, and it adds nutrients too, just doesn't contain nitrogen but plenty of P and K.

What amount of wood ash per/gal would you start with for easing the ph up into a friendlier zone given my low runoff ph values.

 

[Beachwalker]

I water/ feed them today.Plants 1 and 2 feed @
PH 7.01 for both, total 645ppm in plant 1: total 650ppm plant 2
Feed 3... 7.16Ph plain H2O 84ppm (last feed/water too runoff 3-1/2 days ago had 400ppm more in the runoff than I feed it with.)

Runoff from today’s watering.
1:144ppm/5.32Ph
2:124ppm/5.18Ph
3: 334ppm/ 6.09Ph

My ph runoff has hung in this range the whole grow and the plants look like they do now so..I haven’t added anything too raise the soil ph because the plants look like they are doing okay.

Those pH values are very low; look into Dolomite lime for best results, good luck!

 

[Jimster]

What amount of wood ash per/gal would you start with for easing the ph up into a friendlier zone given my low runoff ph values.

I mix a tablespoon or two in a gallon of water. If you use ashes, make sure they are not from treated or household lumber... go out and build a camp fire if needed. FWIW, lye is made by pouring water thru wood ashes, so it will raise your Ph but not drastically. I usually mix a cup full into my 5 gallon buckets when prepping my growing medium.

 

[Ryboburton]

Does that light have a dimming capability

 

[Gasman5.0]

Does that light have a dimming capability

Yes it does. The slight yellowing seen has faded back towards green so I’m assuming the plant with yellow leafs which is my tallest plant and closest too the light source reacted too the new led light and has adjusted itself too it. I did move the light up from 16” too 18” which may have helped idk but they were looking really good before they went too bed last night.

 

[Gasman5.0]

I mix a tablespoon or two in a gallon of water. If you use ashes, make sure they are not from treated or household lumber... go out and build a camp fire if needed. FWIW, lye is made by pouring water thru wood ashes, so it will raise your Ph but not drastically. I usually mix a cup full into my 5 gallon buckets when prepping my growing medium.

Thanks for info Jimster. I’m making my ashes today from some hickory and pecan I have. I’ll mix it in @ 1TBS/gal. and add it in next watering/feed.
Yesterday I picked up a bag of Dolomite lime at the garden center. I read where the finer DL is more affective making its way deeper into medium so I hand ground some of it into a fine dust/ powder and add 2 TBS too each 5 gal pot and worked it into the top of soil really good. I had one TBS of DL dust left over so I ph’d a gal of water too 6.50 and then added the DL dust too it. I hope it’ll dissolve a little in a few days and aid it in reaching deeper into the soil medium.
I’m correct in thinking the ash/water mixture will be even more effective at reaching deeper into root ball than DL since the particles are much smaller.

Much thanks for the advice and wisdom sharing.. this is my first grow and without guidance from you guys my plants and I wouldn’t be where we are today. I’ve learned a lot and I’m constantly reading older threads and learning.. lots of good info here.

 

[Gasman5.0]

https://www.pthorticulture.com/en/training-center/myth-series-water-ph-relates-to-medium-ph/

After reading the link above my water source may very be contributing too low phrunoff Ive always had. I’ve been using the same brand of filtered spring from the grocery store since I started this grow and it usual measures ph between 5.20~5.45 with 29~32ppm as bottled. I add any nutes and adjusted too 6.2~6.5 and go with it. Well after reading the Pro-max link I grab my water test kit and measured the Alkalinity of several bottles of the spring water and the Alkalinity was 10~20ppm and 10~15 ppm calicuim carbonate so this may explain why I’ve been recording very low ph valves in my runoff so I did a slurry test just now and I’m at ease with results.. Water I used for the slurry test measured ph 6.97 and 0 ppm.
Slurry test values= 6.28ph 193ppm.
Runoff for this plant three days ago was 5.18ph 124ppm and the previous 4 runoff test were in the same range 5.18~5.30 and ppm as well.
I’m switching too tap water, it’s 74ppm and ph 6.94 out the faucet with a Alkalinity of 50ppm and 35ppm calcium carbonate.

 

[Jimster]

https://www.pthorticulture.com/en/training-center/myth-series-water-ph-relates-to-medium-ph/

After reading the link above my water source may very be contributing too low phrunoff Ive always had. I’ve been using the same brand of filtered spring from the grocery store since I started this grow and it usual measures ph between 5.20~5.45 with 29~32ppm as bottled. I add any nutes and adjusted too 6.2~6.5 and go with it. Well after reading the Pro-max link I grab my water test kit and measured the Alkalinity of several bottles of the spring water and the Alkalinity was 10~20ppm and 10~15 ppm calicuim carbonate so this may explain why I’ve been recording very low ph valves in my runoff so I did a slurry test just now and I’m at ease with results.. Water I used for the slurry test measured ph 6.97 and 0 ppm.
Slurry test values= 6.28ph 193ppm.
Runoff for this plant three days ago was 5.18ph 124ppm and the previous 4 runoff test were in the same range 5.18~5.30 and ppm as well.
I’m switching too tap water, it’s 74ppm and ph 6.94 out the faucet with a Alkalinity of 50ppm and 35ppm calcium carbonate. View attachment 997596

I always just use the local tap water... it has enouh but not too many minerals in it and is pretty low in chlorine content. On a side note, be careful when adding ashes and ground up lime as the lime can take a while to do it's work and can often overshoot your goal and keep progressing to alkaline conditions... but very slowly. Slow enough that you will be pulling your hair out trying to figure out why things are turning badly for no apparent reason. You will probably be fine with what you are doing, but just keep an eye on the outflow's Ph to make sure it doesn't creep up.
Keep up the good work!