CalMag Def or Too much Light?

[planttechniques]

 

[planttechniques]

 

[Limeygreen]

I would get some epsom salts in there, those pinkish stems with that blotchy leaf colour look like Mg def to me. 1 tsp per gallon for foliar and 1 tbsp per gallon drench. Extra calcium never hurts either though if you have the boron.

 

[dimodz]

I would get some epsom salts in there, those pinkish stems with that blotchy leaf colour look like Mg def to me. 1 tsp per gallon for foliar and 1 tbsp per gallon drench. Extra calcium never hurts either though if you have the boron.

good tip dude

 

[Chevy cHaze]

Hey PT,
Am I right in assuming that you are growing under LEDs? It's quite common for plants to have increased Mg and Ca requirements under LEDs, especially the latest generation SMD chips which are super intense. I can't believe how much CalMag I'm pouring into my plants ;-)
CC

 

[flylowgethigh]

I have been adding cal mag to my reservoir, as well as Ph'ing the water to 6.5. The plants seem much happier. Having the lights higher also seems to help, but the temps get higher for warming the moist air.

 

[planttechniques]

Hey PT,
Am I right in assuming that you are growing under LEDs? It's quite common for plants to have increased Mg and Ca requirements under LEDs, especially the latest generation SMD chips which are super intense. I can't believe how much CalMag I'm pouring into my plants ;-)
CC

yup, Mars Hydro FC3000 in a 3' x 3' x 5' tent

the 5' height is definately a challenge with the 4" carbon filter hanging from the top of my tent

the mars hydro does have the latest samsung diodes so maybe that's the answer, I never realized that diodes could cause an increased need for CalMag but it makes sense now

Thanks everyone, I'll try and add more calmag, up the pH to 6.5 and do an epsom salt foliar

 

[Chevy cHaze]

Yeah LEDs have always required a bit more CalMag in my experience since the time I switched over from HPS to LED. Now with the newer super intense chips it has become more pronounced. But if you give them enough the light intensity and what it does for growth and yield can really surprise you.
Take care
CC

 

[planttechniques]

Yeah LEDs have always required a bit more CalMag in my experience since the time I switched over from HPS to LED. Now with the newer super intense chips it has become more pronounced. But if you give them enough the light intensity and what it does for growth and yield can really surprise you.
Take care
CC

yeah, that's why I kept turning my Dimmer up from 50% to 60% to 75% then to 100% because the plants were exploding with growth and I was addicted to how fast they were growing and I realize now that CalMag def can take some time to show up so I increased the light intensity faster than I could give them enough CalMag.

I still think part of it was light burn but everyone (Dr. Coco, migrolight) (even the manufacturer Mars Hydro) said the ideal hanging height was 18" and that's exactly where I had my light so I was trying to figure out why no one else was having light burn at 18" yet I was even at just 60% on the dimmer

It's like there is a linear relationship between CalMag and light intensity but the light intensity can be turned up faster than the calmag so in a linear relationship the calmag will definitely show up to late to notice

 

[Chevy cHaze]

I have a bunch of Mars Hydro TS1000 and I too find they'Re better hung a bit higher than manufacturer recommendation.
CC

 

[planttechniques]

update: I've switched to Grat3fulh3ad's 6/9 GH formula and increased the Epsom salt every watering (starting at 1g/ml / gal to 4 ml/gal in this pic) and I'm seeing MORE Mg def. I think my coco is too wet and flushing the Mg first since I water to 10-20% run-off (but only once per day).

Help

 

[planttechniques]

took a while for the Mg to be absorbed and trans-located to where it was need in the plant but now that I use 4mg/gal epsom salt and 1mg CalMag/gal every watering the plants seem a lot happier now and much darker green when I view them under normal light

Thanks for all the help everyone (I'd like your posts but I guess that's only possible after I post 50 times?)

 

[planttechniques]

 

[planttechniques]

here's a time lapse

 

[flylowgethigh]

The problem with epsom salts is the reservoir starts gaining EC per the truncheon. I add a lot of cal-mag (mine also has iron) in the veg tent, but the plants in the flower tent don't have the darker veins in the leafs, so they must not want it. I have stopped the cl-mag there.

I have the lights in the veg tent about 30" or more above the tops. In the flower tent they have grown to within 2' of them. I have the flower lights at 90%, about 800 umoles at the tops, which is all they probably want at 450PPM CO2. Temp in the tent also drives the light power setting.

What's strange is the light outside is so much more intense. Those two plants I kicked outside are stretching with the less light hours/day.

 

[JustGrowing420]

I got the exact same problem, mine was a deficiency though.
I was underfeeding by a lot and 3 weeks into bloom middle-upper fan leaves started getting lighter in color and after some days brown spots.
Was wondering if it's light stress too, as some of my plants are very close to the light.
When I corrected the feed the deficiency slowed down and stopped progressing after about 4 days maybe?
I am not using led also, 600w hps and peat but some of my strains showed calcium deficiency even 2 weeks in veg.
One last thing, I top dressed with some gypsum, 15g, to offset the low ratio of calcium to magnesium in my cal-mag (~3:1).
We'll see how that goes though as I did it the last two days.

 

[jackspratt61]

Spray mgsu4 at 1 tbsp per gallon followed by .8% solution of MAP. Light 'snow' of gypsum topdress and stand back.

 

[planttechniques]

I'm now using 3ml/gal epsom salt and 3ml/gal of CalMag at each watering and that seems like the right amount to correct the deficiency. Plants are much greener now that I have done that and the plants growing closer to the light don't seem to be getting burn like before.