Leaf Margins Turning Yellow

[Jelimafish]

Tent: 20”x20”x48”
Light: Mars TS1000
Soil: Fox Farm Ocean Forest with 30% Perlite
Pot Size: SOLO Cups to 3 Gallon Fabric Pots
Ventilation: 4” Exhaust Fan with Carbon Filter - Small desk fan
Age: 23 days old
Temperature: 77 (Range from 68-84F - generally sits around 80)
RH: 40%


I am hoping that someone can help me identify the cause of the leaves turning yellow. The first true leaves on both plants turned completely yellow/crispy so I removed them, I thought maybe the plants were just adjusting to the FFOF. The next oldest leaves have started the same process and now the leaves just slightly younger are also starting to do the same thing. I have searched and the closest match that I can find is Magnesium deficiency so last night I fed both plants with Cal-Mag at full strength, hopefully this was the right move. Any help is greatly appreciated!

 

[Brotofsky]

I’m all DWC, but in a lot of threads people have said that the soil you are using is hot. Are you also using nutes?

 

[Jelimafish]

I’m all DWC, but in a lot of threads people have said that the soil you are using is hot. Are you also using nutes?

I used some Nutes after topping Monday but at 1/4th strength so it was 1.5 tsp of Big Bloom and .5 tsp of Grow Big in a gallon of water and they only got a cup of that each. Other then that I have only fed the Cal-Mag at full strength last night.

 

[Jelimafish]

I’m all DWC, but in a lot of threads people have said that the soil you are using is hot. Are you also using nutes?

I am doing DWC next run, excited to see how that turns out! :)

 

[Brotofsky]

Hopefully some pros will chime in, but I would stop the nutes and use just water. Why would you use bloom nutes in veg?

 

[Jelimafish]

Hopefully some pros will chime in, but I would stop the nutes and use just water. Why would you use bloom nutes in veg?

I was just following the feeding schedule and I have to flip to flower in a week or two because my grow space is not very tall. The Big Bloom is a veg nutrient and the Grow Big they call for starting at week 2. The feeding schedule dosage is 6tsp of Big Bloom and 2tsp of Grow Big per Gallon so I started with 1.5tsp and .5tsp. The discoloration started about a week after they popped so I am pretty confident the feeding didn't make anything worse, I will definitely just be watering with PHd water until I can pinpoint this. Thank you so much for responding, I am sure I will have 1000 questions about DWC when the time comes :)

 

[nicolajanjak]

for me its typical of too much bloom nutrients too early .. too much p and k in it, kinda blocked the N
and yes your soil looks too hot ..
and im not talkin about that margin burnt leaf, but of the global plant

 

[Jelimafish]

for me its typical of too much bloom nutrients too early .. too much p and k in it, kinda blocked the N
and yes your soil looks too hot ..
and im not talkin about that margin burnt leaf, but of the global plant

Thanks, I mean overall they look great to me and the new growth all looks healthy so I will just use straight ph'd water for a while and see what happens.

 

[MIMedGrower]

Likely fertilized too early and there are plenty of nutes left in the soil. They can continually break down and feed the plants for up to 6 weeks in my experience.

If you add nutes too early the roots get blocked and the medium becomes too high ec. Too many nutrients will actually start starving the plant and it will show deficiency.

I suggest water only to good runoff next time and let dry out real good before the next time.

Dont add more cal mag. It is not likely needed in soil. Plenty of calcium and magnesium in soil.

 

[Jelimafish]

Likely fertilized too early and there are plenty of nutes left in the soil. They can continually break down and feed the plants for up to 6 weeks in my experience.

If you add nutes too early the roots get blocked and the medium becomes too high ec. Too many nutrients will actually start starving the plant and it will show deficiency.

I suggest water only to good runoff next time and let dry out real good before the next time.

Dont add more cal mag. It is not likely needed in soil. Plenty of calcium and magnesium in soil.

This all started two weeks ago prior to any nutrients being added. The only food they have gotten was Monday after topping which was 25% of recommended and they only got maybe 8 oz each with no changes after feeding. If this was caused by too many nutrients wouldn't feeding them make things worse? I am definitely switching to plain water but am just curious.

 

[Beachwalker]

Tent: 20”x20”x48”
Light: Mars TS1000
Soil: Fox Farm Ocean Forest with 30% Perlite
Pot Size: SOLO Cups to 3 Gallon Fabric Pots
Ventilation: 4” Exhaust Fan with Carbon Filter - Small desk fan
Age: 23 days old
Temperature: 77 (Range from 68-84F - generally sits around 80)
RH: 40%


I am hoping that someone can help me identify the cause of the leaves turning yellow. The first true leaves on both plants turned completely yellow/crispy so I removed them, I thought maybe the plants were just adjusting to the FFOF. The next oldest leaves have started the same process and now the leaves just slightly younger are also starting to do the same thing. I have searched and the closest match that I can find is Magnesium deficiency so last night I fed both plants with Cal-Mag at full strength, hopefully this was the right move. Any help is greatly appreciated!

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What PH are you feeding at?
Use 6.5 in ffof for best results.

There's plenty of everything in the soil but you're likely locking some things out; do a slurry test & post results

 

[MIMedGrower]

This all started two weeks ago prior to any nutrients being added. The only food they have gotten was Monday after topping which was 25% of recommended and they only got maybe 8 oz each with no changes after feeding. If this was caused by too many nutrients wouldn't feeding them make things worse? I am definitely switching to plain water but am just curious.

If you had not fed yet had you watered in the plant fully? Or are you watering small amounts? If so the roots could grow into dry soil and burn.

Either way. That plant in that big pot would not need any nutrients yet. It is not an issue of nutes not being available.

 

[Aqua Man]

Looks pretty dry to me

 

[Jelimafish]

What PH are you feeding at?
Use 6.5 in ffof for best results.

There's plenty of everything in the soil but you're likely locking some things out; do a slurry test & post results

I have been using 6.2 to 6.5 but it is usually around 6.4 since my tap water comes out around 7.4 and 1ml of the Ph Down drops it 1.

 

[Jelimafish]

If you had not fed yet had you watered in the plant fully? Or are you watering small amounts? If so the roots could grow into dry soil and burn.

Either way. That plant in that big pot would not need any nutrients yet. It is not an issue of nutes not being available.

I have been watering every day or two and usually add water slowly until I see a little come out of the bottom of the bag then stop.

 

[Jelimafish]

Looks pretty dry to me

The last photo was from about 8 days ago and was about 36 hours after transplanting. When I transplanted I watered them really well then let it dry out until I watered again. The soil doesn't look dry to me in the most recent photos.

 

[Jelimafish]

My next soil grow I think I will start in Rock Wool then transplant to something not as hot as FFOF then when they go into their final pots use the FFOF to transplant. It seems like it will be easier to diagnose any potential issues with way less factors in play.

 

[MIMedGrower]

I have been watering every day or two and usually add water slowly until I see a little come out of the bottom of the bag then stop.

Well the soil looks dry in the pic. But the plant shows signs of overwatering. Same as a lock out from too much nutes the roots can not function in too wet soil and will yellow and then show all kinds if deficiencies. Adding nutes would make it worse.

I suggest letting the pots dry out until they are very dry and light. A probe moisture meter would read in the dry zone 3/4 down the pot.

Young plants in soil dont need water every day. Mine in 1 gallon pots can go 5 days or more.

 

[Beachwalker]

The last photo was from about 8 days ago and was about 36 hours after transplanting. When I transplanted I watered them really well then let it dry out until I watered again. The soil doesn't look dry to me in the most recent photos.

Did you calibrate your meter? because when I see leaves turning crispy like that, especially in fresh Ocean Forest I think pH, again a slurry test will tell you what's going on with your soil / root situation & post results.

if you need information on slurry test its 2 to 1 soil to distilled water mix it well let sit for 15 minutes

but it's no good unless you know you're calibration is correct on your meter? that's what I'd check first, good luck!

Edit: in my opinion foxfarm ocean Forest being hot is hype there's only problems when growers feed copious amounts of newts too early; I did a slurry recently on a fresh bag and it was under 500 ppm and around 6.4, imo that's not hot

 

[Jelimafish]

Well the soil looks dry in the pic. But the plant shows signs of overwatering. Same as a lock out from too much nutes the roots can not function in too wet soil and will yellow and then show all kinds if deficiencies. Adding nutes would make it worse.

I suggest letting the pots dry out until they are very dry and light. A probe moisture meter would read in the dry zone 3/4 down the pot.

Young plants in soil dont need water every day. Mine in 1 gallon pots can go 5 days or more.

Awesome, thank you so much!