Help sick babies!

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trontreez

Well-Known Member
I need some help with my sick plants :( They are around 4-6 weeks old grown from seed. I've had trouble since adding the nutrients after around 2 weeks. Growth is very slow. Older leaves show yellowing beginning at the ends and progressing to burning of the leaf tips. There is also some drooping of leaves and darkening in the middle of leaf veins on certain plants. I was using GT coco grow parts A+B @ 1/4 strength. Not sure if it's nutrient burn, over-watering or pH imbalance. Any help would be appreciated.

Grow info:
Grow tent: 1m x 1m x 1.8m
Light: 400w HPS, plants 70-80cm from lamp
pH: ~6 using color-metric indicator (balanced with lemon juice, solution goes up to 7 after a few days. Will start using commercial pH down)
Nutrients: Growth Technology Coco Grow, Parts A+B, 1/4 strength
Temps: Very High, up to 35c (close to 100F ?)
Humidity: Very Low, 30-40% (any ideas to get higher???)

NB: I was still having the same issue when growing under 2 x 3ft fluorescent where the temp. was in the good range 24-27c, and humidity between 50-70 %.

Plants 3&4 are next gen. romulan
Plant 2 is likely romulan
Plant 1 is romulan or Nirvana's Chrystal
 

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trontreez

Well-Known Member
Don't think it's a heat issue IMO as the problems was occurring when i was using fluro's and the temps were mild. It's currently only 30c in the grow room. Outside temps get really hot here so the room can get up to 35c but it's not always that high. I can lift the lamp about half a foot or higher from the plants but don't think that will make much difference temp wise. Other than using an AC unit (which I can't really afford to use) how could I get my temps down ?
 
Nice Ol Bud

Nice Ol Bud

Well-Known Member
Fix temperatures, roots are boiling.
Also pull back on the nutrient's.

And your using coco mix I guess. Put some vermiculite in there.
 
FlightSchool

FlightSchool

Active Member
trontreez said:
Don't think it's a heat issue IMO as the problems was occurring when i was using fluro's and the temps were mild. It's currently only 30c in the grow room. Outside temps get really hot here so the room can get up to 35c but it's not always that high. I can lift the lamp about half a foot or higher from the plants but don't think that will make much difference temp wise. Other than using an AC unit (which I can't really afford to use) how could I get my temps down ?
Click to expand...

30C is hot, 35 is way too hot. 26C is ideal

I would ditch the HPS until you can bring your temps down, I'm not saying that is your whole issue but it's definitely adding stress.
 
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imchucky666

Well-Known Member
trontreez said:
I need some help with my sick plants :( They are around 4-6 weeks old grown from seed. I've had trouble since adding the nutrients after around 2 weeks. Growth is very slow. Older leaves show yellowing beginning at the ends and progressing to burning of the leaf tips. There is also some drooping of leaves and darkening in the middle of leaf veins on certain plants. I was using GT coco grow parts A+B @ 1/4 strength. Not sure if it's nutrient burn, over-watering or pH imbalance. Any help would be appreciated.

Grow info:
Grow tent: 1m x 1m x 1.8m
Light: 400w HPS, plants 70-80cm from lamp
pH: ~6 using color-metric indicator (balanced with lemon juice, solution goes up to 7 after a few days. Will start using commercial pH down)
Nutrients: Growth Technology Coco Grow, Parts A+B, 1/4 strength
Temps: Very High, up to 35c (close to 100F ?)
Humidity: Very Low, 30-40% (any ideas to get higher???)

NB: I was still having the same issue when growing under 2 x 3ft fluorescent where the temp. was in the good range 24-27c, and humidity between 50-70 %.

Plants 3&4 are next gen. romulan
Plant 2 is likely romulan
Plant 1 is romulan or Nirvana's Chrystal
Click to expand...
2 weeks is usually early to start feeding, Yes, that DOES look like nute burn.
Your PH is low, and you should try not to keep your water after mixed longer than a day or so.
What does your tap PH start at?
If you need to lower it a lot to get it around 6.5, try Distilled white vinegar instead of lemon juice.
I use the cap from the Heinz jar to measure, 1 cap per liter usually bring mine down almost a full point.
Have you checked your soil PH?
What kind of soil is that? It looks like wood chips........
Get a good fan going in there, try and get an exhaust fan to pull air from high up where there is more heat, and your intake fan down low where air is cooler.
Keep a wet towel in front of your circulation fan for the RH.
 
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trontreez

Well-Known Member
imchucky666 said:
2 weeks is usually early to start feeding, Yes, that DOES look like nute burn.
Your PH is low, and you should try not to keep your water after mixed longer than a day or so.
What does your tap PH start at?
If you need to lower it a lot to get it around 6.5, try Distilled white vinegar instead of lemon juice.
I use the cap from the Heinz jar to measure, 1 cap per liter usually bring mine down almost a full point.
Have you checked your soil PH?
What kind of soil is that? It looks like wood chips........
Get a good fan going in there, try and get an exhaust fan to pull air from high up where there is more heat, and your intake fan down low where air is cooler.
Keep a wet towel in front of your circulation fan for the RH.
Click to expand...
My tap pH is around 8 using a color-metric indicator. I was using around 3.5mL lemon juice concentrate + nutes to 2L solution to make it around pH 6. I have bought a commercial pH down (phosphoric acid) and will start using that instead.

The medium is coco mixed with coarse perlite soil-less mix. I didn't think it was necessary to measure the soil pH should I be doing so ? should I still aim for pH 6.5 with this medium.

I already have an exhaust fan attached to the reflector. But will get another circulation/intake fan for plant level and use the wet towel trick. Thanks for the tip!
 
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trontreez

Well-Known Member
I'm starting to think it may actually be a Magnesium deficiency. The tips of upper leaves now have a grey/whitish look about them. Also the burning on the lower leaf tips curls upwards. Any chance this could be the case ? Btw the plants are outside now so they are not exposed to the very high temps for as long and the humidity is much better there.
 
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