Magnesium deficiency?

[NPK]

Hey y'all, wondering if I might get some feedback regarding a deficiency or possible lockout problem I'm seeing in my current grow. I think it's a magnesium deficiency but am not certain. Here are the deets:


What STRAIN are you growing? Hindu Skunk
What was the establishing technique? (Were the seed or clone?) Clone
What is the age of your plants? ~ five weeks
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? Three weeks into flower
What substrate/medium are you using?(Hydroton, RockWool etc.) coco coir
What is the Water temperature? ~ 70F
What Nutrient's are you using? How much of each if using multiple? FloraNova Bloom
What is the TDS/EC/PPM you are using? Last reading was 970PPM
What is the pH of the "Tank"? Same as above
Are you sure your calibration is correct on your equiptment? Yes--I just cleaned the probes
When was your last watering? The plants receive water 5x daily
When was your last feeding change? (ie. grow-bloom-micro-additional) four days ago
What size bulb are you using? three 600-watters
What is the distance to the canopy? 12" from the glass
What is your RH Factor? 45-50 percent
What is the canopy temperature? 80 degrees
What is the Day/Night Temp? (Include flucutaion range) Not sure what the night temp is--probably mid 60s this time of year
What is the current Air Flow? (cfm etc.) Room is kinda-sorta sealed; there is an intake covered with a filter, and I'm enriching with CO2
Is the fan blowing directly at plants? On some of them, yes
Is your water HARD or SOFT? It's 70PPM out of the tap
Has plant been recently pruned, cloned off of or pinched? No
Have any pest chemicals been used? If so, What and When? No
Are plant's infected with pest's? No

Some pictures:

I've foliar-fed the plants with an epsom salt solution (under the assumption it's an Mg problem), but it doesn't seem to be helping. What do you think the problem is, and how can I correct it?

 

[High Jinks]

you never said what ph your feeding at, AND what the ph of the runoff of it is. Also, watering 5 times a day is a lot, even for coco. Flush with PH'd water and she will thank you.

 

[20kw dreams]

Looks to me like your fryin them. You ever flush them out? Flush them, back off on the ferts, and pull the lights back a bit. Is this more towards the centers of the light print? Where is the thermometer you are getting 80 degrees at? Put it directly under the light, but cover it so it doesn't get direct light, then give us the temps. I'll bet it's way higher. It's still a burn, but it may be brought on by high temps, probably over 85 under the lights.

 

[DontBanMe]

if it was a light burn it should be affecting the leaves higher on the plant and not burn leaves under the top of the plant. It looks to me like a Phos. def....it maybe a possible lock out issue. I would flush out with a cleaning solution like Flora Sheild somthing or that sort. and then put the ppms back up around 800 and go from there.

Heres a Phos. def. plant and it shows that V shap on your leaf, or course this is a little more servere but i think its almost identical.

Photo from www.ganjaguerrilla.net

hope this helps

 

[Blackvelvet]

Looks to me like your fryin them. You ever flush them out? Flush them, back off on the ferts, and pull the lights back a bit.

I agree. There is plenty of magnesium and phosphorus in floranova bloom. I don't think this is a deficiency but an excess. You never mentioned ph. I would aim for around 6.

8ml per gallon fnBloom...in ppms
n 124
p 108
k 180
Mg 62

Note ppms of individual elements like above is totally different than what a ppm meter says.

Maybe try aiming for around 75 ppm nitrogen . So using the known numbers above 75/124 x 8ml = 4.8 ml per gallon



.

 

[HeadyPete]

You can try, but blackvelvet doesn't know if this will work for you because he never grew a plant. Take his advice at your own risk or be burned like many before you.

You don't mention ph and that is probably your problem. You want ph at 6.5, not "aim for around 6", as the no experience, nongrower suggested. That is something someone would say if they didn't know but wanted to fake knowing. Unfortunately only the noobs here fall for it.

 

[NPK]

Oops--yeah, I forgot to mention ph. I keep it at about 5.8; last night it was at 6.0 (5.8-6.2 is the optimal range in coco). I would tend to think I'm frying 'em, except the problem appears on leaves from around the middle of the plant to the second or third internode from the top--which is what made me suspect a magnesium deficiency. The temperature sensor is right at the top of the canopy. As for flushing, I generally do that right before each week's reservoir change.

dontbanme, the pic you shared is indeed closest to what I'm seeing and where I fear these plants may be headed. I'm still gonna take 20k's advice and flush, and lower the nute strength--I usually shoot for around 750PPM but upped the nutes last time I changed the tank.

 

[DontBanMe]

do your thang! hope they get green for ya

 

[NPK]

So, I ended up bringing my camera to the local hydro store and showing the guy my pics. He took one look and said that it looked as though the plants would benefit from Cal-Mag. That thought had crossed my mind as well, and it was good to hear it confirmed by this dude--a hell of a nice guy who's helped me before and whose judgment I trust. He says that plants' Calcium requirements go up in flowering; and I may be wrong, but I believe I've read there's an important interaction/relationship between Calcium and Phosphorus, so I still think there may be a P issue here (tip o' the hat to DontBanMe). So, I'm gonna flush, change the reservoir, and add 3ml of Cal-Mag per gallon, plus some B1 to assist with any shock. Then hopefully the plants will be better able to metabolize the Phosphorus in the FloraNova Bloom.

Thanks to all of you who posted. With any luck I'll be able to come back and put up pics of greener, healthier plants.

 

[Amber Trich]

You showed who? what?

oh my

 

[JohnnyToke]

"So, I ended up bringing my camera to the local hydro store and showing the guy my pics." :jawdrop:

now that takes some balls my friend.

I had a very similiar looking (almost exact same looking leaves) issue as yours a few months ago and found out I was burning up my plants with nutes because I thought my hanna ppm meter was a conversion of .7 and it was actually .5 thus scorching them. Once I figured that out, flushed and got the correct ppms under them, they regained their health and finished out fine.

good luck.

Regards,
JT

 

[NPK]

Yeah, I guess it does sound kinda nuts, huh? But c'mon, those guys know exactly what people are buying their products for--same thing they're selling 'em for. Probably makes everyone on both sides of the counter feel safer, pretending it's all for the vegetable garden. True, he would only look at the pics in the back room--but whattya know? He wasn't the least bit shocked they weren't of bell peppers. Point well taken, though. Maybe it's easy to get a little too comfortable living where I do.

Anyway--I hope the Cal-Mag restores the girls to their former green luster.

 

[DontBanMe]

(tip o' the hat to DontBanMe).

No problem bro, i always try to help where i can. I really think it may have been a build of salts and you need a nice good flush for the platns to start taking in what they really need. Hope it works out for ya man.
later

 

[20kw dreams]

You can try, but blackvelvet doesn't know if this will work for you because he never grew a plant. Take his advice at your own risk or be burned like many before you.

You don't mention ph and that is probably your problem. You want ph at 6.5, not "aim for around 6", as the no experience, nongrower suggested. That is something someone would say if they didn't know but wanted to fake knowing. Unfortunately only the noobs here fall for it.

Well, I say "aim for around 6" because a real grower knows if you "aim for around 6" then you will be around 6, which is a nice safe place to be, which gives you room either way. Or, you can be anal, and make sure it is 6.00

I could really get into the "why"s of alot of things, but it takes time I don't have. I'm not trying to bash anyone here, for real, but it is not a P def. We give our plants MUCH higher P then they need, to increase size and mass of flowers. That pic you posted of the P def is a intentional deficiency brought on by NO Phophorous, and is from Canna's photo library.

When I said salt burn in a hot spot, I meant salt burn from excessive heat, not light or heat burn. There is a difference, in that the damage is not caused by the heat persay, but from excessive transpiration in fan leaves causing an excessive build up of salts. Resin and size of smaller tops leaves prevents these leaves from getting these burns. I have a hot light at the end of my run of 4 1000's, and I get this just about every run on the top fan leaves, but not the upper bud leaves.

 

[DontBanMe]

sorry wasnt tryin to call you out in anyway trust me, i not trying to get banned again. i misunderstood you bro, im sure you know what your talkin about, its just a real bitch tryin to help people online and not actually being there you know what i mean?

 

[MynameStitch]

Dude, NPK you really did take your pictures to the ****ing hydro shop guy??? WHy don't you already take the pics to the police station already????

GEESH dude.... wtf did you end up doing that!? Sounds like to me you do not need to be growing... not trying to be rude, but damn man........

It looks to me it was a mag issue but it never got fixed in time so the area the mag issue affected; the leaf tissue turned necrotic ( dead); but it looks like you have some salt buildup in that coco...

how often are you feeding them and how much?

You water them 5 times a day!?

 

[NPK]

Heya Stitch--I actually live in a city in which the plant is legal for medical patients, of which I am one. My grow is legit (not to say that others' aren't, but you take my meaning). Marijuana busts are specifically legislated to be the lowest law enforcement priority, and as a matter of fact, there is a busy dispensary located right next door to the police station. Finally, I am acquainted with the shop proprietor--we've spoken many times before. I wouldn't have shown the shots to just any hoodie-wearing kid behind the counter. As I said, the point is well made and well taken: discretion is crucial, and one shouldn't get too comfortable even in a Prop 215 city. Still, it'd be nice if folks would stop doing this: :

Yep, frequent waterings are common amongst coco growers. I started doing it on the advice of the mod on the coco forum, and my plants took off. Now I only hand-water once-daily when I need to slow down the rate of growth. They aren't over-watered in the slightest because the medium holds so much oxygen. The root zone actually benefits from the fresh O2 that's pulled through with each watering. I would never water soil that often; coco's another game entirely.

And yeah, I thought it looked like a magnesium deficiency, too. Flushed the pots thoroughly last night, filled the reservoir with fresh nutes (and 3ml Cal-Mag per gallon) at 750PPM, and noted that the reading was down a bit to 720PPM this morning. So, we'll see if there's any improvement in a week or so.

I'm going to give your plant-health sticky a thorough read. It's good stuff, and I appreciate your and everyone else's feedback.

 

[MynameStitch]

Ahhh, I see; well that's cool then. I was like omg! Cause I Have seen pot smokers do some really dumb stuff; especially when they post it in the newspapers and say:

Pot smoker calls cops to report stolen marijuana; gets arrested!
I have seen it soooo many times now.....

Oh ya I know coco growing; just I have never seen a person water 5 times a day.... 3 times ya.. but not 5 times.......


What brand of coco are you using? You wash it really good before ya used it?

 

[NPK]

Yean, I didn't even think about how it might've sounded and really should have. It could be considered lax.

Oftentimes I get bales of Down to Earth coco at my local gardening center; you get half again as much as the pre-bagged stuff for only about $15, as opposed to $23, but it's not rinsed. So I rinse it until the PPMs are down to tap water level (70 in my area). However, the current girls are in B'cuzz. I paid a premium because I was pressed for time that day and didn't want to rinse. I was unlucky, though, because the PPMs came out at 1600! Had to rinse anyway.

Tank PPMs are down to 680 this evening, and the plants don't seem to be getting worse--which is progress at this point! Stitch, thanks to your guide I noticed a definite early calcium deficiency. Hope that Cal-Mag fixes things up.

 

[MynameStitch]

You got spotting on your plants? I did not see the spotting on your plants when you took the pic; you got a pic of the problem?

Ya, that is nuts and it's a pain in the ass when you gotta rinse all that coco.... so you get what you pay for; some people would pay less and do it themselves which is not a problem; but if some people do not know they gotta rinse it out first.... they got a major problem on there hand if they pay for a brand that did not rinse out the coco!