Unusual spots on leaves.. looking for advice.

[whaler007]

popped on 1/3/2021
2.3x2.3x5.25FT MarsHydro tent
MarsHydro TS1000, 22 inches above highest growth, 100% strength (moved to 25 when I saw the spots this morning)
Grow Medium: Mother Earth Coco Plus Perlite Mix (70 coco 30 perlite)
Genetics: Greenpoint Seeds, Purple Crash
PH: 6.3-6.5 measured before nutes, tap water.

Nutes: botanicare CAL-MAG plus & general hydroponics series.

1tsp micro and gro, .5tsp bloom .4 tsp cal-mag
in 1 gal of tap water with 79 PPM
brought to 533 PPM with nutes

I'm guessing that they're from the light as I just turned up the intensity from 80 to 100 a few days ago. I'm a beginner so I want some clarification and tips, thanks!

 

[Mcwhippin420]

Looks almost like calcium in a way but could be light burn if its only on the top portion of leaves?
Normally when the leaves cup like they want to hold water in them it means heat stress

 

[oill]

popped on 1/3/2021
2.3x2.3x5.25FT MarsHydro tent
MarsHydro TS1000, 22 inches above highest growth, 100% strength (moved to 25 when I saw the spots this morning)
Grow Medium: Mother Earth Coco Plus Perlite Mix (70 coco 30 perlite)
Genetics: Greenpoint Seeds, Purple Crash
PH: 6.3-6.5 measured before nutes, tap water.

Nutes: botanicare CAL-MAG plus & general hydroponics series.

1tsp bloom and gro, .5tsp bloom .4 tsp cal-mag
in 1 gal of tap water with 79 PPM
brought to 533 PPM with nutes

I'm guessing that they're from the light as I just turned up the intensity from 80 to 100 a few days ago. I'm a beginner so I want some clarification and tips, thanks!

Are you reducing the ph to 5.8?

 

[whaler007]

Looks almost like calcium in a way but could be light burn if its only on the top portion of leaves?
Normally when the leaves cup like they want to hold water in them it means heat stress

calc def?
the two plants that are closer to the heater are the ones that have that slight cup so ill move the heater around. The environment is controller by a fancy controller though so it shouldn't be getting too hot.
lower leaves had this spotting problem earlier on but I believe that at the time they were the highest leaves, I learned that I had the light way too close at the time, and once corrected they didn't get worse.

Are you reducing the ph to 5.8?

I reduce to 6.3 ish before every watering. I store 3 gal of nute water in a 5 gal bucket for a few days before I run out.

 

[Mcwhippin420]

Yeah but the more u say the more it seems light stress but I grow soil so ph and all that is a greater factor but id give it a day or 2 see how reacts. I imagine as the light was raised the cupping will fade and should be fine

 

[oill]

calc def?
the two plants that are closer to the heater are the ones that have that slight cup so ill move the heater around. The environment is controller by a fancy controller though so it shouldn't be getting too hot.
lower leaves had this spotting problem earlier on but I believe that at the time they were the highest leaves, I learned that I had the light way too close at the time, and once corrected they didn't get worse.




I reduce to 6.3 ish before every watering. I store 3 gal of nute water in a 5 gal bucket for a few days before I run out.

Not low enough! Aim for 5.8 in coco at the start of the grow and end up at 6.1

Are you watering/feeding til you get run off every day?

 

[whaler007]

Not low enough! Aim for 5.8 in coco at the start of the grow and end up at 6.1

Are you watering/feeding til you get run off every day?

I was watering every other day until around 20% runoff (probably more), the pots would still have some weight after 24h, and I got some of that green mold on the surface which indicated that the top wasn't drying before the next water. They seem to be drinking more so I will be watering every day from now on and reducing to 5.8. Thanks for the help hopefully that clears it up.

Yeah but the more u say the more it seems light stress but I grow soil so ph and all that is a greater factor but id give it a day or 2 see how reacts. I imagine as the light was raised the cupping will fade and should be fine

yeah, I think I talked myself into the answer. Thank you for helping!

 

[Mcwhippin420]

I was watering every other day until around 20% runoff (probably more), the pots would still have some weight after 24h, and I got some of that green mold on the surface which indicated that the top wasn't drying before the next water. They seem to be drinking more so I will be watering every day from now on and reducing to 5.8. Thanks for the help hopefully that clears it up.



yeah, I think I talked myself into the answer. Thank you for helping!

No problem at all I had a little light stress on mine a month ago or so ! Good luck

 

[Rurumo]

Some ppl might disagree with me, but you're at the point where you should probably start feeding once per day. Less than that and you run the risk of your ppms shooting up in the coco as it dries out-watering at least once per day will keep the ph and the ppms more stable. This article explains why https://www.icmag.com/ic/showthread.php?t=307683. I wouldn't worry too much, you're doing good-you will probably need to start adding a little more calmag though. I agree with ph at 5.8 going in. It isn't necessary to test runoff, but sometimes it can help you troubleshoot things in a general way, so maybe check your runoff ph and ppms. I'm using a new water source and didn't realize how high my coco's ph was until I checked runoff-then did a slurry test one day. Lowering my nutrients to 5.8 and watering to a bit more runoff has since corrected the issue. I have more alkalinity in my water than you though. Good luck! and nice plants!
Ruru

 

[MickFoster]

Plants in coco should be fed daily to substantial run using a pH around 6.0.
Never let it get dry.......even the top.
Never give plain water.

You didn't mention that you give any micro........just grow and bloom.

Here's a proven feeding chart for coco using GH Flora Series nutes.

 

[whaler007]

Plants in coco should be fed daily to substantial run using a pH around 6.0.
Never let it get dry.......even the top.
Never give plain water.

You didn't mention that you give any micro........just grow and bloom.

Here's a proven feeding chart for coco using GH Flora Series nutes.
View attachment 4804992

my mistake, It was an error I corrected it. 1tsp micro and gro, .5tsp bloom .4 tsp cal-mag.

I never give plain water, unless I needed to flush. (which I haven't)

I don't let the top get "dry." my understanding is that if you see a tiny bit of light-colored coco it's time to water and if you get the green algae that means that it has been a little too wet.

also, my pic shows dry coco on the surface because I added a little extra on top since it was low.

I am feeding daily from now on.

Thank you for that feed chart, I never come across that exact one during my research and ill be sure to use it as a reference!

 

[whaler007]

Some ppl might disagree with me, but you're at the point where you should probably start feeding once per day. Less than that and you run the risk of your ppms shooting up in the coco as it dries out-watering at least once per day will keep the ph and the ppms more stable. This article explains why https://www.icmag.com/ic/showthread.php?t=307683. I wouldn't worry too much, you're doing good-you will probably need to start adding a little more calmag though. I agree with ph at 5.8 going in. It isn't necessary to test runoff, but sometimes it can help you troubleshoot things in a general way, so maybe check your runoff ph and ppms. I'm using a new water source and didn't realize how high my coco's ph was until I checked runoff-then did a slurry test one day. Lowering my nutrients to 5.8 and watering to a bit more runoff has since corrected the issue. I have more alkalinity in my water than you though. Good luck! and nice plants!
Ruru

I appreciate this. Cool thread and a great read, it for sure helps me understand a little more about how everything functions. Would you recommend that if I don't see an improvement over the next few days that I add some more calmag? I will be watering every day from now on with 5.8 ph. Thank you!

 

[MickFoster]

Thank you for that feed chart, I never come across that exact one during my research and ill be sure to use it as a reference!

It comes from www.cocoforcannabis.com.......if you want to know how to grow in coco, that's the best place.
Good luck.

 

[Mcwhippin420]

Ya me to ive always went soil...always thought about trying coco

 

[whaler007]

It comes from www.cocoforcannabis.com.......if you want to know how to grow in coco, that's the best place.
Good luck.

quit question about that grow chart, I tried doing just 2.5ml micro and grow and about 1ml of bloom per gallon but the PPM only went up about 200. That's why I decided to double it and go with the chart provided by general hydroponics to get my PPM to go up 400. Any idea why I don't reach the PPM target described in that chart?

 

[MickFoster]

quit question about that grow chart, I tried doing just 2.5ml micro and grow and about 1ml of bloom per gallon but the PPM only went up about 200. That's why I decided to double it and go with the chart provided by general hydroponics to get my PPM to go up 400. Any idea why I don't reach the PPM target described in that chart?

Are you adding all the same additives and supplements that are on the chart?

 

[whaler007]

still don't look good.. any ideas? PLants are still growing though.

 

[Son of a collier]

give them a foliar feed with your regular nutrient solution and give your plants some ph corrected water, you have given them too much potassium and probably too much phosphorous too.
(water at least once but pref twice a day in coco) feed with every irrigation & mix and meter your nutrients in a larger container or use a reservoir and make a good batch of your nutrients otherwise you will be forever mixing and hoping its the same as the last one lol.
Don't add any bloom boosters until you see some buds.
also try not to cal mag too much regardless of how they look. I give a dose at bloom week 2 and another half strength dose at bloom week 5
I generally get 27oz from my 2x1 meter tent with 2 dimmable 600w hps running at 450w each

 

[bernie344]

give them a foliar feed with your regular nutrient solution and give your plants some ph corrected water, you have given them too much potassium and probably too much phosphorous too.
(water at least once but pref twice a day in coco) feed with every irrigation & mix and meter your nutrients in a larger container or use a reservoir and make a good batch of your nutrients otherwise you will be forever mixing and hoping its the same as the last one lol.
Don't add any bloom boosters until you see some buds.
also try not to cal mag too much regardless of how they look. I give a dose at bloom week 2 and another half strength dose at bloom week 5
I generally get 27oz from my 2x1 meter tent with 2 dimmable 600w hps running at 450w each

Any pics?

 

[whaler007]

give them a foliar feed with your regular nutrient solution and give your plants some ph corrected water, you have given them too much potassium and probably too much phosphorous too.
(water at least once but pref twice a day in coco) feed with every irrigation & mix and meter your nutrients in a larger container or use a reservoir and make a good batch of your nutrients otherwise you will be forever mixing and hoping its the same as the last one lol.
Don't add any bloom boosters until you see some buds.
also try not to cal mag too much regardless of how they look. I give a dose at bloom week 2 and another half strength dose at bloom week 5
I generally get 27oz from my 2x1 meter tent with 2 dimmable 600w hps running at 450w each

Thank you for the tips. Do you believe that the excess potassium and phosphorous is due to my water PH being high? I've been at 5.8 - 6 for the past week or so.