Whats causing this browning?

[NotSoGreenThumb]

Med
ium-Coco coir 40% perlite

Light- 600w mh

Grow space- 3.5'x3.5'x7'

Temp/RH- 70-73F/30-40%

Nutes-Floranova bloom/Calmag

Tap water @ 200ppm


First coco grow. This seedling started funky from the beginning. It is three weeks old. The first week it got ph'd water at 5.9-6.1. After a week I started a very mild feed at <1/4 strength(150-200ppm). Growth was painfully slow and purple so I bumped my nutes up over the past two weeks and it has exploded. My problem is my first set of true leaves, they are browning and crisping. The new growth is rapid and Im sure the plant will make it but, I would like to know if anyone has any thoughts on what could have caused this. I have looked everywhere for the same problem and got a general answer of "it just happens". Like I said this is my first grow in coco, not first grow, I've never had this happen on such young plants.
......

 

[deadgro]

Some kind of deficiency, probably ca, mg, etc. But new growth looks good so you've fixed it.

 

[IGROWINTORONTO]

^ its harder to fix older growth always check new growth for signs of deficiencies. Your new growth looks spot on.

 

[NotSoGreenThumb]

Getting the same problems on my second node(first node now crispy about to fall off)...really hope this isnt an ongoing problem..looks a little like cal def. Imo...any takers?

 

[butterbudface]

Looks like a Mg def, not 100% sure

 

[chuck estevez]

why are you feeding them flora nova BLOOM and cal/mag? I would say you burnt them

 

[NotSoGreenThumb]

Im using the "lucas formula". I have read coco has a tendency to hold onto calcium and not give it to the plants in in the amount it needs , that it is good practice to add a little cal mag each feed. Im at week 4 adding 1/4 nutes. New growth is good, just seems like everytime a new node grows one one starts to die off.


Could really low humidity cause a problem such as this? My rh was really low for a few days (16-25%)

 

[deadgro]

Lucas can suck deez nutz.

 

[NotSoGreenThumb]

Lucas can suck deez nutz.

Ok?

 

[deadgro]

Ok?

The 3 part works better.

 

[NotSoGreenThumb]

The 3 part works better.

Thanks for the tip

 

[Dr. Who]

Coir NEEDS added Ca/Mg....

Nothing wrong with FloraNova nutes..Just don't use bloom until like week 2 of bloom! Veg nutes first! Add Ca/Mg at every watering.

Be sure to flush the media every 2-3 weeks to prevent salt build up associated with Coco.

 

[NotSoGreenThumb]

Would also like to note the inner growth has a lot of curling and twisting?

 

[Sunny Organics]

it does look overfed, and those spots on your fan leafs can indicate a calcium deficiency for sure. What i think is you overfed with nutrients, i can see red stems in your plant as well which might be because of your cal-mag. the yellow dots and red stems are for sure a calcium and magnesium problem, if youre still having problems with that make sure you consider that.

For your new growth been twisted/deformed, mainly caused by potassium which your nova is high in, is another sign that you overfed.

When did you start feeding your plant?
are your problems still present?
how is your new growth?

 

[NotSoGreenThumb]

it does look overfed, and those spots on your fan leafs can indicate a calcium deficiency for sure. What i think is you overfed with nutrients, i can see red stems in your plant as well which might be because of your cal-mag. the yellow dots and red stems are for sure a calcium and magnesium problem, if youre still having problems with that make sure you consider that.

For your new growth been twisted/deformed, mainly caused by potassium which your nova is high in, is another sign that you overfed.

When did you start feeding your plant?
are your problems still present?
how is your new growth?

Thanks for the reply! I started feeding a very very mild nute solution after week 1 when the first trues showed up(less than 1/8 recommended strength). Ive been gradually increasing nutes every 3 or so days now feeding 400ppm of bloom/grow (I alternate every feed or so) with 2ml of cal mag each feed. The plant gets fed once a day with 30-40% runoff. I flushed for the first time a couple days ago untill runoff was significantly lower in ppm (close to my tap water)to remove any salt buildup that could have occurred in case of overfeeding. New growth on top doesn't seem to be affected as much as the side shoots. The browing/crisping/yellow spots/red stems are continuing to show up more each day.