Blueish leaf tint?

Whats causing my leaves to have a blueish color?

Plants are 6.5 weeks old. 1kw MH. Soil is 40% FFOF, 60% FFHF, mixed heavy with perlite. Temps are 64 at night, 74 during day. Water is rain or RO. PH is a little high. Very lite nuets: Usually a full dose of CalMag, although there have been two full doses of kelp extract so far this grow. Plants were showing signs of needing calmag before I started with it. The plants look good, but they're blueish looking. This picture looks close to the color after minor tweaking in photoshop.


This next photo has not been tweaked.

looks good to me

You didn't mention the strain of the plant? I have Blue's in my garden.

Look hungry for a balanced base nute. Possibly too much calcium if giving cal mag. Blue leaves. Twitsting tips up top. Calcium problems starting.

But not necessarily from needing more cal mag.

If ph is going high they may just be eating more NPK.

Nice Plants!
I never really paid attention to the purple leaf conversations before except for hearing that cold temps bring it out.
Curious if his temps go down to 64 and lets say dropped a degree or two lower on a cold night, say 62. Could the blue be an early phase of purpling?
An indoor plant that doesn't normally purple. Would cold temps make it turn blue-green? How low would the temps need to drop?

how cold is the water ur giving it?

Your fine, the lite green of the new growth is fucking with you.

Strain is a bit of an unknown. It's American Haze from Growers Choice. I can't find any info on it in any databases. According to them it has "origins in plants native to South America, Thailand, Mexico, and South India." So it's probably bag seed, lol.

Water is room temp, about 68. I don't think it's a PH issue. These plants saw only rain water for the first 4 weeks. Rain water measured out at 5.5ph, which is normal. Sitting for awhile, it went up to 6.5 or so, again normal. The last few weeks it's been getting RO water, which measures out at 7.4ph. Both rain water and RO water are extremely low in buffering, so I'd expect the soil to go where it wants to go PH wise. I have only been feeding lightly. In the first few weeks they only got half dose of silica supplement, mainly to raise the ph a little. Week 3-4 they got a full dose of kelp (one on each week). Last week I gave them a half dose of GH bloom. Calmag is another story, but let me explain.

Here's a shot from week 4 where I started seeing a deficiency on new growth. Poor picture, but notice the spotting on the right leaf, on the lower three petals.

From what I've read, I was expecting possible nutrient problems from using rain water/RO, so diagnosed this as magnesium (or maybe manganese) deficiency. At this point I started adding a teaspoon/gallon of Calmag to most waterings. The problem cleared up mostly, but I still get leaf twist on new growth. The plants are growing vigorously, and look beautiful. I'm just trying to learn here, mostly.

if u got some micronutrients like GH's Floramicro then it couldnt ever hurt to give her some of that and some calmag to be safe.

jarvild said:

You didn't mention the strain of the plant? I have Blue's in my garden.
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Your leaf color looks a lot like what I'm seeing. Your plant looks fantastic.

Lite said:

if u got some micronutrients like GH's Floramicro then it couldnt ever hurt to give her some of that and some calmag to be safe.

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I'll pick some up.

Usually when ive had my girls doin strange things that I just dont understand and the internet cant answer, its a deficiency in one of the metals. Usually iron or zinc in my instance.\

@deno
Your plants in here look like they need Iron. It causes that bright green inner growth, its super common but you can fight back with micronutrient solutions.

Floramicro is 3tps/gal in veg and 2tsp in flower, its like 12$ a quart. Looks like super dark blood, kinda gross really. Thats the reason I use it.

Just ordered a quart. I'll give it a shot. What's the shelf life on nutrients? Was going to order a gallon, but didn't know.

Not too sure, I just don't like locking into 1 brand that much. A quart will last me 1-2 grows typically and I like the flexibility of deciding if I want to continue it or change. I always change my nutrients a little bit each grow.

deno said:

Your leaf color looks a lot like what I'm seeing. Your plant looks fantastic.

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I suspect your pH is off a little.

jarvild said:

I suspect your pH is off a little.

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It might be, but I don't think that's what's causing this blue. It's either...

1. Not enough magnesium. I had a magnesium deficiency, and started adding calmag. It fixed it somewhat, but not entirely. I still have some twisting of leaf in new growth. They might need even more mag. I'm very conservative when adding chems to my grow.
2. Micronutrient deficency.
3. Strain, coupled with low temps
4. I'm adding calmag, and the plants need mag. Could be an over abundance of calcium.

Unless this soil is really fucked, it's not PH. Could be the soil is really wacked, though. Next grow I'm cooking my own so I know what it is. It should be noted, though, that I might be in error with the initial diagnoses of mag deficiency.

i still stand by the opinion that the plants actually look really healthy with a some minor metal deficiency

im surprised that noone has mentioned that they probably look blue because of the MH, typically the spectrum is pretty blue heavy, in late flower when the fall colors start showing my plants look like a banana plantation under the HPS but under natural light the plants are still quite green.

Your plants look like theyre quite healthy. micronutrients may be an issue, but i think its more of just your lighting tbh.

Gumdrawp said:

im surprised that noone has mentioned that they probably look blue because of the MH, typically the spectrum is pretty blue heavy, in late flower when the fall colors start showing my plants look like a banana plantation under the HPS but under natural light the plants are still quite green.

Your plants look like theyre quite healthy. micronutrients may be an issue, but i think its more of just your lighting tbh.

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Interesting. I'm switching to HPS in a week. Just flipped to a short cycle. I'm going to start with micronutrients, too, along with continuing calmag. And watching PH more carefully, so we'll never know for sure. All these ideals help - I'll get it sorted out eventually. I'm still deep in the learning curve.