Upward curling of leaves and couple brownish spots

[Mr. Sandman]

Hi new grower here I have some seedlings about 2 and a half weeks old I notice some upward curling of leaf tips and one of them has just a couple brown spots I thought maybe I got water on them when feeding and it got burnt by the light but now I am wondering if the combination is a problem that's developing or if I'm just over worrying as a new grower and should wait it out any help or advice would be greatly appreciated


Problem: leaf tips curling up and couple brownish spots

Medium/grow method: coco coir perlite mix

Feed: and supplements used: general hydroponics micro and bloom,protekt, Epsom salt ph down. Ec at 0.7 ph at 5.8

water source:10 gal nute mix in RO water

Strain/age: mephisto sour crack 2 1/2 weeks

light used:1000w metal halide 6500k ballast running on 50%

Climate:75-77 degrees f 50-55 percent rh

Additional: nothing seems to be progressing I have 6 going all given the same feeding this is the only one spotting still growing healthy and daily new growth

 

[Waira]

how far away are the lights? Seedling want less intense light vs older plants,... looks like some minor edge rolling,.. T and RH% are good, but no sudden spikes/drops in them? ..sometimes they just grow oddly too,.. Are you using Ca-mg with every watering/feeding? A necessity in coco, which is a Ca binding hog,..

 

[Mr. Sandman]

I started it out as high as my space would allow and slowly dropped the light over the course of a few days only running at 50 precent on my ballast during the day I check rh and temps often but haven't seen any spike or drop in them my hygrometer reads highs of 80 and lows of 40 so I'm not sure if I'm dropping at night while I work or if my hygrometer isn't working acurratly I couldn't see that drastic of a change happening over 8 hours though I bought another hygrometer today gonna see how the readings look tomorrow I have heard some just grow oddly and older leaves die off so I wasn't sure if I was just over worrying as a new grower my friend got me started using same style setup as him and he seems to do really well I mix a 10 gal res of nutes only half strength not sure off hand of exact measurements im at work or would check but I use protekt ph down hydrofarm micro and bloom epsom salt for mag no calcium booster h2o2 I mix up a 10 gal half strength and feed off that till I need to make a new batch only thing I readd is the h2o2 every 3 days per bottle instructions.thank you for the help and advice waira I really appreciate any advice to better my cause

 

[Waira]

Sour Cracks! -- an AFN favorite,... not large plants by any means, but the density and potency are tops, straight up- ...nothing but raves on this strain! I need to score some myself,...
I wouldn't worry about the minor leaf distortions, young leaves do odd things sometimes,... If you have reduced power on the lights, and keep it at least 2' from the plants For absolute sure, get a proper Ca-Mg product, something low in N, GH has a good one,.. Coco has peculiar cation exchange properties (CEC), which includes serious preferential Ca binding, Mg to a lesser extent,... they must be sated first, or it'll keep the Ca/Mg from the plant potentially,.... Are you doing a drip system or Autopots? .... why peroxide? this is lethal to beneficial microbes you know,...
If you haven't researched coco well, do so mate, it's anything but a soil! ..Not like other soilless media either (Promix, etc.),.. we have a great section here on it, and Canna USA has tons of info at their site,... In many ways, it's more like hydro,.. pH, nutes,....I'm not a coco grower, so the fine points I'm not savvy with,...

 

[Mr. Sandman]

That's what I have read about it I'm excited to try it out I didn't use calmag because a friend of mine got me started and when he used the calmag it gave him alot more issues and cause his plants to get sick so I run the same formula he has been running its a modified lucas formula. An because I have seen the results so I was trusting him on what he was doing since I am new that's why I wanted to join a forum to get advice from all kinds of people same reason I run h2o2 that the formula he runs and it works well so just trusting him to get me going suppose to kill bacteria and provide oxygen to the water better from what I'm told wasn't aware of killing potentially good bacteria but his formula works and he has been the only one I have to take advice from. He said the calmag threw his calcium way off and spiked his N cause sick plants so he now stays away from it. I will definitely be experimenting more though. I am setting up a drip system in smartpots. So far everything is growing really well nice green color only the on leaf with those couple spots it hasn't spread an no others look bad at all. And thank you alot for the advice I'll take all advice I can get and like I said I will have to experiment

 

[Yeatster]

Listen to Waira. He is THE man. You need Cal/Mg! Most have Nitrogen added. Like my man says, General Hydroponics has one with no NPK. They also carry one with some N. Be sure to get the one with 0-0-0.
Agree with the wierd leaf curl happens sometimes. If your RH and temps are on point, I wouldn't worry, should level out soon. Good luck!

Shout out to Waira! Long time, my friend.

 

[Waira]

well, this is what my research says about coco,.. I don't know your friends situation, so I can't second guess what he did right and/or wrong,... I know some folks overdo the Ca-Mg, and cause pH and lockout issues because of it, but much depends on the brand/quality of coco,.. bad stuff, poorly prep'ed/aged will still have too much Na and K in it, native cations bound to it,.... lucas is running just micro and bloom, right? ... coco breathes better than soil/peat by far, so extra O2 isn't that advantageous in smaller pots from what I've learned,..it's one one reason why you don't need to use larger volume pots with coco, and can grow monsters in silly-tiny pots! One of my homies grew about a 1oz plant in a 32oz cup- -- of course, he was watering/feeding 2x a day!
anyway, no further progression on the spots? The Ca-Mg from GH/GO is now all 1-0-0, very light N so that's fine,.. some out there are 4-0-0, or higher! ---** (Yeats, GH/GO have changed the formula on CaMg+, it's all now 1-0-0).... does your friend run drip? Done right, this can grow beasties!... but you need to have serious run-off to purge build-ups, like 20% I believe,... She looks fine otherwise Sandman, so carry on!

:smoking: Cheers Yeats! ...don't over-sell me on coco brudda- -- you know I'm a dirt guy!

 

[Mr. Sandman]

Lol I will definitely be trying it out to see how it works with my setup thank you both for the advice on the kind to get I would of been lost on that. Yes micro and bloom it's modified by a guy on another forum gr3atful h3ad that's where we got the epsom instead of calmag idea he subs epsom for calmag.
In the coco, I am now using 6ml/gal micro and 9ml/gal bloom which gives the nute profile:
N 97
P 60
K 105
Mg 41
S 27
Ca 97

adding 1 g/gal epsom salts to the solution changes the numbers for mg and s to:
Mg 67
S 61


Adjusting for the extra available potassium in the coco, the new formula puts me very close to the 'target ratio'... Phosphorous is a tad low, but I think there should be no worries there... so with that formula my Cal don't really go out of range just my mg and s that's why use the epsom to sub for calmag. But not knocking any advice or disagreeing by any means just explaining my reasoning for how I am running it. will definitely be giving the calmag a try though thank you both for the great advice it's always appreciated an welcome

 

[Mr. Sandman]

And yes my friend runs drip he has actually tried over watering in coco by setting them to runoff 6 times a day just to see if he could over water in coco but they never drooped or missed a beat they actually seem healthier with the heavier feedings in coco. And also my resevoir temps are a bit high 72-74f would like them to be 65-68f so the h2o2 also kills any bad bacteria so I don't get root rot or other issues haven't had the extra funds to get a chiller yet so I don't have to worry about it as much. But yes no progressing on the spots it hasn't spread on that plant or showed up on any others so far keeping a close eye on things will keep things updated stop in and check them out from time to time

 

[Waira]

....well, some nutes seem to have enough Ca in them as is, plus well prep'ed coco hogs less (already loaded more or less),... some folks use lower ppm tap water, or blend ro and tap,.. it's the CaCO3 in harder water that's involved with pH buffering,..specifically the carbonate anion part,... Some folks mistake epsoms for a Ca source, but as you know it's not, only MgSO4 in there,...
Right then, carry on!