Plants showing a combination of different symptoms

[d42zero]

Hi,

I've got three plants going which have all developed some unhealthy symptoms but they're all pointing towards different things. I'm a very very novice grower (this is my first time around) so any info I put here is only going of stuff I've read, and the main source of info so far has been the 'Grow Weed Easy' site.

I have begun to 'manifold' the plants as per the instructions on the GWE site, mainly because I grow basil in the summer and I do a similar thing with it so it's the technique that felt familiar. The first step is to top the plant just above the 3rd node, and remove the 1st and 2nd nodes so only the 3rd+fan leaves are left. I did this five days ago on plant #2, and two days ago on plant #1 and #3. I waited to do #1 and #3 so I would have a little lead time for correction if #2 started showing signs of distress.

Plant #1 is showing brown spots on the leaves consistent with online photos of a manganese deficiency, and the leaves are drooping a bit:

Plant #2 is showing similar spots, but the leaves are curling up consistent with online photos of heat stress:

Plant #3 is actually looking pretty damn sexy but is starting to develop the same brown spots:

These symptoms all showed up over the past 24 hours, all plants looked extremely healthy this time yesterday. I did change my nutrient ratios quite significantly after buying an EC pen (about three days ago), I significantly reduced my cal-mag as my tap water read very high (141ppm) and I almost doubled the nutrients as the first mix at my previous ratios only came to about 400ppm and I was aiming for 600, but after some testing it seems my EC pen is wildly inaccurate so I may have a bad mix.

The light is a 315W LEC approximately 18" (450mm) from the top of the plants. The clones are at the bottom of the tent and off to the side, so would be at least 2ft (600mm) away.

I think the logical answer is to mix up a batch of nutes the same as the mix I was using before I got my EC pen and flush using that, then to get a decent quality EC pen and re-mix.

I also took the cuttings I removed from all three plants, dipped them in rooting gel, and kept them in jiffy pucks. The one that looks the healthiest (on the left) is from plant #2 so has had longer to recover, the other two are still a bit weak after being cut. And yes I let them dry out a bit too much! I figure some stress is normal with cuttings, and it seems the one that was done first seems to be recovering ok:

All advice is greatly appreciated! <3

 

[TysonOG]

You need more cal mag. The brown, rust like spots are calcium and the cupping that you believe is heat stress, is actually magnesium deficiency. Not uncommon as calcium and magnesium go hand in hand. There's an old saying, that the leaves are "praying" for magnesium lol. A lot of times it is heat stress but in this case, I say magnesium. 141ppm is pretty low for tap, even on the 500 scale, and with coco you'll need calmag even more, especially if you didnt wash and buffer the coco before you started. I would add 2ml calmag per gallon. I recommend gen hydro calmag because it has low nitrogen.

 

[d42zero]

Thanks @TysonOG! I made a big mistake by doing multiple things at once... I changed my cal-mag, my nutes, and topped the plants... thanks for narrowing it down I'll mix a new batch of nutes with a bit of cal-mag, the schedule I was using was up at 13ml per 10l or about 5ml/gal and they seemed to like that.

I only added a tiny amount of cal-mag as Cultivator's coco thread says to add cal-mag to 150ppm and 141 was almost there. That being said my EC meter sounds like it's a dud so I think I'll go back to what I was feeding them last week until I can get my hands on a decent meter.

I did charge the coco with a fairly heavy water/cal-mag solution but I don't think I did it enough, I only did it to runoff one time. I probably should have done it a couple of times before transplanting but they were growing so fast I had to move them!

I'm using GH's flora trio and Calimagic

Thanks again

 

[TysonOG]

Ok cool, you're not doing that bad then. This is my first run in hydro but just came from coco, and spent a ton of time on cultivators threads, hes the man. I think hes saying 150ppm if your using straight ro water. In theory, if your ppm is 0 and you bring it up to 150 with calmag, the entire 150 is calmag. But if your tap water is 150ppm it is not 100% calmag. I hope that makes sense. I run 2.5ml personally and suggest 5ml as a "max". Luckily too much calmag doesnt really affect the plant up to a certain point of course, so as long as you dont go over 5ml you should be fine.

My ro starts at 40ppm and 2.5ml calmag brings it to about 250ppm (700 scale) just for reference.

 

[d42zero]

If your ppm is 0 and you bring it up to 150 with calmag, the entire 150 is calmag. But if your tap water is 150ppm it is not 100% calmag.

That does make sense. I actually just looked up the local water quality table after posting that comment and they say that the median calcium reading is 15ppm and the median magnesium reading is 5.... so I suppose I could consider that water as 15ppm if we're mainly interested in cal-mag? In that case would I add cal-mag until I get a 135ppm increase then, if his formula says 600ppm, add nutes until I got a 450ppm increase?

So 141ppm from the tap + calmag to 276ppm + nutes to 726ppm?

For now I'll just go back to my previous mix maybe with a bit less calmag than I was using before, definitely need to get the pen situation sorted before relying on it to mix :/

 

[TysonOG]

Dont worry about your ppm being exact or even super close, a 50ppm difference isnt gonna hurt anything as long as your ratios are right. That being said, you need to know if your pen is on the 500 or 700 scale, and you also need to know what scale Cultivator is referring to.
1ml calmagic is roughly 80ppm on the 700 scale. In your case I would start between 2-4ml per gallon. Normally you start low and work your way up, but with a deficiency start high and work your way down.

 

[d42zero]

Thanks @TysonOG, I figured on using those numbers as just a ballpark, just need something to aim for. I'm currently using the GH stuff at half strength, I was planning to bump up the strength a little from the next mix but this little mistake might put that back a few days.

Instead of mixing a new batch I've added 3ml/gallon worth of cal-mag to the existing mix... that way in a few days I'll be able to tell 100% if it was the cal-mag by what the plants do. I've already made the mistake of changing two things at once so I'll only change one thing at a time from now on!

Transplanting the clones into seedling pots tonight. The coco for those is soaking in nutes with a little extra cal-mag

 

[Barney86]

Just give them a quarter of whatevers on the bottles mate. They don't need much in coco. That lot are on
270ppm GT grow
30ppm scillica
48ppm tap water
And they've had a total of 3 shots of calmag at 50ppm. And that was to deal with iron def cause I've been lazy with my ph.
Id say It's more likely that you're not feeding often enough and too strong so the ph of the coco is drifting too high and that's locking it out. You getting run off every day mate?

 

[d42zero]

Hi @Barney86, I'm torn between the 'water to runoff when top 1" is dry' advice and the 'water at least once daily with no runoff' advice from Cultivator's thread. My plants are up on trivets so I can water to runoff and not *have* to drain it as the pots won't sit in the runoff anyway, but I've been watering measured amounts until I just get the tiniest bit of runoff mainly to not waste nutes. I might double water tonight to runoff and test the pH to see if it's high..

Would you suggest maybe watering down the nute solution I have now and flushing that through? Or just flushing through the current solution I have? What I have mixed up at the moment is about 1/2 strength from the label with 3ml/gal cal-mag.

 

[Barney86]

The thing with coco mate is it doesn't break stuff down like soil does. Its basically just an empty sponge with zero nutritional benefits. It doesnt do anything. Any nutes that aren't absorbed turn back into salts and just sit in the coco.
So if you feed it like soil and give it a wet/dry cycle then before long the salts build up and can cause just about anything to happen. Tox, def, burns, lockouts, ph can swing massively in iether direction.
Sometimes its bad sometimes its not but they'll all be hard to fix because you'll be trying to answer the wrong questions.
Like this for instance. Everyone jumped straight on the calmag bandwagon because you do indeed have mag def.
Just that it's not, imo, caused from a lack of mag.
you're more likely to trust a majority which I get. Especially when it's experienced guys but I did just guess you're watering habits right after explaining why I thought that and I'll bet if you check the run off it's not what goes in.
If you look at my plant on the very right you'll see the pot sits in a 5l tub. I water it till that tub is full and top it up every 2 days. Run off should be perfectly safe to leave coco plants in. If it's not then the feed is wrong. Think how a hempy bucket works. It's basically leaving the plant in it's run off the full grow.

Also, in the case of DTW coco like you're doing. If your feed is the right strength and you feed lots every day you can just keep re-using the run off. Leave a wee airstone In the nutes and they'll keep for a week easy.
Lots of people think that sounds insane but just think how a Wilma system works. Just pumps the same nutes through the coco over and over and over. Absolutely no reason you can't do it handwatering.

There's lots of myths around growing mate and I can bust em all lol

 

[d42zero]

Thanks for the info! I watered one plant to runoff and caught a sample from the first 100ml or so... pH going in was 5.83, coming out was 6.50. 904ppm going in vs 846ppm coming out. Does that sound ok?

Very interesting about re-using the runoff, I was actually going to ask that question. Do you need to occasionally adjust pH of the recycled nutes or just let it creep around?

EDIT: and I see what you're doing with that tub, I have deep trays for my plants that would hold a fair bit of liquid, 3-4l easy. I've seen a few other people say they do this with coco too so that's interesting. Do you test the water in the tub regularly or just leave it? Do you dump and re-fill occasionally?

 

[TysonOG]

I can't argue with Barney86, a very well-respected grower. Watering strategy is super important in coco and its a good idea to make sure that is dialed in. It could very well be the problem. I was more worried about coco's cation exchange sites grabbing what little cal he was giving, as he said he had severely reduced the calmag amount. There might be plenty of mag but it is not as useful without the proper ratio of calcium, no?

 

[MickFoster]

Was you coco pre charged with calcium and magnesium?

 

[d42zero]

We'll know in a couple of days, I'm going to keep doing what I'm doing for now and just see if the extra cal-mag helps. If that doesn't work I'll try something else, but I'm definitely only going to change one thing at a time for now

@MickFoster Yep charged with 27ml/10l (2tsp/gal) then I've been adding 13.5ml/10l (1tsp/gal) to my nute mix. I reduced that to 1.5ml/10l (1/8th tsp/gal) on the 18th of June, I haven't put any other significant changes in the diary in the past week so I'm hoping Tyson is on the right track

 

[PE636]

@Barney86 will have you on the right track. I'd just add that 18" light distance is possibly a little close while the plants are stressed out and suggest raising it by 6" at least. I don't get over 500ppm in coco and that's including 100 ppm water. Stopped using calmag a while back unless its actually needed. Have needed it for one plant since. Frequent feeding at low ppm and correct ph + a dialled in environment = success in coco.

 

[Barney86]

Thanks for the info! I watered one plant to runoff and caught a sample from the first 100ml or so... pH going in was 5.83, coming out was 6.50. 904ppm going in vs 846ppm coming out. Does that sound ok?

Very interesting about re-using the runoff, I was actually going to ask that question. Do you need to occasionally adjust pH of the recycled nutes or just let it creep around?

EDIT: and I see what you're doing with that tub, I have deep trays for my plants that would hold a fair bit of liquid, 3-4l easy. I've seen a few other people say they do this with coco too so that's interesting. Do you test the water in the tub regularly or just leave it? Do you dump and re-fill occasionally?

I just leave the water in the wee tubs mate. I've got magical nutes from growth technology and realised about 6 months ago that even though when mixed they sit around ph7. For some reason I can feed it straight away without ph adjusting it and it works perfectly. They're not advertised as ph perfect or anything like that and I've no idea why it works but it does. So I don't even ph the nutes for coco anymore.
Wouldn't last a week if I tried it in the reservoirs but for some lucky reason my plants ph fix themselves in coco.
The ph of recycled nutes will drift a little. Best to just change it though. Should last a week in the right ph range and needs changed after 7 days anyway.
Your ph is rising because the nutes are too strong. It should rise a little anyway but not that much. Cut the nutes in half, feed more often and she'll be perfect

 

[Barney86]

@Barney86 will have you on the right track. I'd just add that 18" light distance is possibly a little close while the plants are stressed out and suggest raising it by 6" at least. I don't get over 500ppm in coco and that's including 100 ppm water. Stopped using calmag a while back unless its actually needed. Have needed it for one plant since. Frequent feeding at low ppm and correct ph + a dialled in environment = success in coco.

Oh yeah I totally forgot about the light. Nice save mate! And thank you so much for being on my side with the no calmag feeding. You've no idea how happy it makes me to know there's at least 1 other person that's seen the light lol.

 

[d42zero]

Thanks again for the tips guys. I re-tested the runoff from the plant that I put the extra water through and a sample from the first 100ml of runoff was 6.5, once it had all drained through (20min or so later) the pH of the runoff was down to 5.8 on the nose. I've just put the same extra amount through the other two plants and will drain the runoff away, then feed again in a few hours and maybe do a third feed a few hours after that.

When I read back through my notes I also realised that I went from feeding twice per day to a small amount of runoff (once at lights on, once 5-6hrs later) to once per day with no runoff, so I guess that could have contributed to a buildup. Cultivator's thread talks more about just watering enough so that they feel a bit lighter the next feeding but maybe he's got his nute solution a little more dialled so that things like this don't happen... my notes tell me I was getting better growth when I was watering twice per day so I think I'll go back to that.

Oh and I jacked the light up about six inches, thanks for that idea.

I'll pop an update in here as soon as anything changes

EDIT: sorry I should add that I diluted my solution to 50% to use for the extra, then re-pH'd to 5.8. Ended up at 450ppm. Will just keep using this for now as it's pretty close to the mix I was using last week.

 

[d42zero]

Quick update, brown spots appear to have stopped spreading, all plants had about a litre of runoff in the trays this morning after being watered with a total of 1.5l each over two waterings. Emptied trays and discarded runoff, will go back to watering at lights on and again a few hours later rather than just once per day.

Will mix a new solution today aiming for about 450ppm in total. I'm going to keep my ratios the same (including the calmag) for a couple of days to just make sure things stay OK, then I think I will try reducing my calmag a bit while still aiming for the same final ppm number to see if that's ok.

I just ordered a HM COM-80 EC pen so I can get my numbers more accurate.. it's the bottom end of the range but a step up from the $10 free-post-from-hong-kong rubbish on eBay, it will at least allow me to calibrate which is good

Thanks again for all the tips, hopefully got it under control again!

 

[BeanTownFan420]

You need more cal mag. The brown, rust like spots are calcium and the cupping that you believe is heat stress, is actually magnesium deficiency. Not uncommon as calcium and magnesium go hand in hand. There's an old saying, that the leaves are "praying" for magnesium lol. A lot of times it is heat stress but in this case, I say magnesium. 141ppm is pretty low for tap, even on the 500 scale, and with coco you'll need calmag even more, especially if you didnt wash and buffer the coco before you started. I would add 2ml calmag per gallon. I recommend gen hydro calmag because it has low nitrogen.
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