Help please - possible Cal/Mag deficiency? DWC Creme de la Chem

[LeakyBucket]

DWC (6" netpot in hydroton, 3.5 gal bucket), 2 gallon RO water + 2ml GH Micro + 2ml GH Flora Nova Grow + 2ml CalMag +1 tsp/gal Hydroguard for a light solution of 340ppm/5.7pH. Indoor 76*F/40%RH, light foliar airflow/heavy solution airstone flow. Under NextLight 150 @ 25%. 2nd DWC grow (1st yielded unbelievably well). Roots look healthy with no smell in res.

Plant is growing pretty quickly, but a little yellower than I would like. Grow diary here: https://www.icmag.com/threads/mephisto-creme-de-la-chem-multiverse.18124002/

At any rate, does this look like Cal Mag deficiency to y'all? It looks textbook to me, but this is my first deficiency. I bumped 2 gal of solution with 1/2tsp Botanicare CalMag and amped the nutes to 420ppm, just to see if I can stop it. I think it's CalMag deficiency, per the Googling I've done, but I'd like to get your thoughts.

Worst case is I do a res change; she's rockin' along, aside from this.

Thanks!

 

[exploziv]

I would add a bit more feed and get a bit wider PH swings. just getting it a bit lower PH to start with might help to get more Ca into the plant. Good luck!

 

[LeakyBucket]

I would add a bit more feed and get a bit wider PH swings. just getting it a bit lower PH to start with might help to get more Ca into the plant. Good luck!

Thanks! I appreciate the advice!

Yeah, with you there on the pH. I'm a huge fan of pH swings. I've been keeping it tight for now (5.7 to 6.1), but I think I'll follow your lead and lean into what I did last time: I'll get down to 5.4, then let the pH drift up to 6.4 and then push it back down to 5.4 (in veg), then ride the opposite direction in flower. At least that's what I did on my last run, and it really seemed to pay off.


I'll probably throttle up to 500ppm over the next day or two, then to 700 after that. Flora Nova really hits high ppm for not a lot of nutes, or at least that's what their charts seem to say anyway.

 

[Creeperpark]

With those hard water spots, it looks like too much calcium to me. Make sure you got a good breeze flowing over your canopy for the best calcium absorption. Keep us posted either way so we'll know.

 

[LeakyBucket]

With those hard water spots, it looks like too much calcium to me. Make sure you got a good breeze flowing over your canopy for the best calcium absorption. Keep us posted either way so we'll know.

Thanks! Can you please help me understand what "hard water spots" means? I ask, because I started with RO (0ppm/7pH) (and I'm easily confused ).

And yeah, will definitely keep y'all posted.

 

[Creeperpark]

Too much cal-mag added to the water will make the water hard.

Understanding Water
The hardness or softness of water is determined by the mineral content of both calcium and magnesium: Soft water has less than 17 parts per million. Slightly hard water has 17 to 60 parts per million. Moderately hard water has 60 to 120 parts per million. Hard water has 120 to 180 parts per million‌ Google

Outdoor hard water sources.
Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, bicarbonates and sulfates. Google

That's why I thought you may have used a little too much cal-mag. because the calcium is showing itself in the leaves. Make sure you have plenty of airflow over the plant canopy to maximize calcium uptake. Either way, keep us posted.

 

[Douglas.Curtis]

You can also skip the grow formula and use only the nova bloom. Cannabis does not need all the nitrogen avaliable at the moment, and you'll get short/sturdier plants with better light distribution on the flowers with your LEDs.

I personally never found any benefit to exceeding 6.1 pH, though I do find 5.4 a great low point. pH swing is crucial for complex enzyme outputs.

Try 500-600ppm(.5 conversion meter) with the low 700's as a cautionary maximum in flower for best quality.

 

[LeakyBucket]

You can also skip the grow formula and use only the nova bloom. Cannabis does not need all the nitrogen avaliable at the moment, and you'll get short/sturdier plants with better light distribution on the flowers with your LEDs.

I personally never found any benefit to exceeding 6.1 pH, though I do find 5.4 a great low point. pH swing is crucial for complex enzyme outputs.

Try 500-600ppm(.5 conversion meter) with the low 700's as a cautionary maximum in flower for best quality.

You know, I'd been thinking about doing that. Something about a different version of Lucas; I probably read about it on here, for all I know.

Perhaps I should transition over to Bloom on my next res change.

Thanks for the advice!

 

[Ca++]

How cold is the water?
It might be a P problem from being a bit cold and wet.

 

[Douglas.Curtis]

I always hung my airpumps in the cold air flow of the a/c unit. Then keep an appropriate sized aquarium heater in there to maintain 68 to 69F for optimal growth and a minimum of issues.

 

[LeakyBucket]

How cold is the water?
It might be a P problem from being a bit cold and wet

75F and steady. Rolling-boil airflow from 4" stone.

Update: I had bumped up the nutes to 500 48 hours ago, and the problem is getting worse. I did a res change, and used:

• 2 gal RO water (0ppm/7.0 pH)
• 5 ml Botanicare Cal Mag
• 5ml GH Flora Nova Bloom
• 10ml HydroGuard
• 5 drops GH pH Down

This took me to 550ppm (500 scale, so 1.1 EC), at 5.8 pH (Apera pen, BlueLabs pen, litmus strip within .1 of each other, both meters calibrated 4/7/10 prior to use).

A couple more questions, if you please:

• Is 2.5ml/gal CalMag too much for a plant this young?
• And should I be talking with y'all in EC, as opposed to ppm? I'm assuming ".5 conversion" == 500ppm scale, am I right? (That was probably a dumb question, but that's how I'm interpreting my Googling...)

Incidentally, the roots are absolutely exploding (smell great, there is the nute staining that you get from Nova, but no slime), the stalk is getting very sturdy, and the plant is steadily growing. Aside from the [advancing brown spots now on the secondary leaves] + [dying primary leaves and cotyledons from the tip, moving inward], she's growing at a pretty decent clip. No other symptoms or alarms aside from that.

I'll keep y'all posted. Sincerely appreciate everyone's input and advice.

 

[Douglas.Curtis]

You will likely have great results until flowering begins and dissolved oxygen demands increase dramatically. At this point the 75F water will not be holding enough oxygen and the plant will wilt and root health will rapidly decline.

69F for maximum growth and absence of issues. Nearly 20 years of awesome, trouble free DWC grows and temp control was key.

 

[LeakyBucket]

You will likely have great results until flowering begins and dissolved oxygen demands increase dramatically. At this point the 75F water will not be holding enough oxygen and the plant will wilt and root health will rapidly decline.

69F for maximum growth and absence of issues. Nearly 20 years of awesome, trouble free DWC grows and temp control was key.

Thanks! Yeah, I've been kicking around the idea of getting a chiller. Any good chiller/pump combos you recommend?

Thinking of this one: https://smile.amazon.com/Active-Aqua-AACH10HP-Chiller-Cooling/dp/B07BHHQLKR

BTW, I've read a lot of your posts, and it's experience and expertise like this that is why I joined this forum.

 

[Ca++]

Flora Nova has a lot of calcium. They don't recommend adding more. Clay also contains a lot of calcium. I have seen these signs a few times in pebbles, as plants get established.

Some of the new growth is stunting hard. I scraped the Nova range realising it was poorly balanced. The bottle spec is non-sense according to the manufacturer themselves. You can see it in the feeding charts, where they estimate the N ppm to be double what the bottle suggests.

I wouldn't move forward with that feed.

A lack of P or Mg or Mn could look much like this. While too much Ca could be behind any of them. I would buy a feed for hydro.

 

[LeakyBucket]

Flora Nova has a lot of calcium. They don't recommend adding more. Clay also contains a lot of calcium. I have seen these signs a few times in pebbles, as plants get established.

Some of the new growth is stunting hard. I scraped the Nova range realising it was poorly balanced. The bottle spec is non-sense according to the manufacturer themselves. You can see it in the feeding charts, where they estimate the N ppm to be double what the bottle suggests.

I wouldn't move forward with that feed.

A lack of P or Mg or Mn could look much like this. While too much Ca could be behind any of them. I would buy a feed for hydro.

Thanks!

What feed/line would you recommend? And how would you transition?

 

[Ca++]

Single part hydro? I would probably use ionic.

I have never bothered to transition between brands. The only reaction to a change that I have seen, has always been a good one.

Ionic is fully chelated so will offer some resistance towards odd bonding.

I would just buy a small amount. It may be just a transition to yet another feed. It's low my both Ca and Mg, and I'm leaning towards Mg perhaps being a problem for you. Did you give the stones a good pre-treatment?

I don't think the Nova is going to work, but just looking at the leaves that bought you here, a spray of epsom would be interesting

 

[Douglas.Curtis]

Maxibloom powder is easy, and when used below 750ppm can turn out decent flower. No calmag, use a pinch of epsom salt for magnesium and the sulfur helps in the production of terpenes. Usually under $20 for a 2.2lb/kilo bag.

Drop your ppm when physical flower bulking quits... you'll notice a big drop in transpiration rates and overfeeding is rather easy at this point. I usually swapped some res water out for a plain r/o addback until transpiration was nearly the same as before, then try to maintain that till the end.

I have no experience with chillers and do not like 'plumbing' attached to my dwc rubs with airstones. Too many bacterial breeding points like RDWC. Ugh!

Always hung my airpumps in the cold air stream from the a/c unit. That air easily chills the res to below 69F, and usually required an aquarium heater for steady 69F.

 

[Ca++]

The question regarding your ec/ppm didn't go un-noticed.
Do you have a pic of your meter?
PPM is never a good start, as there are no PPM meters. Yes you can buy meters making the claim, but it's not actually possible. To get ppm you must boil off the water and weigh the debris. These meters just measure EC and guess PPM by non standard means. They came over from fish supplies, and just stuck in the hobby market. We need to see them gone. However lets see it... It can be made it work. It's just a number.

 

[LeakyBucket]

The question regarding your ec/ppm didn't go un-noticed.
Do you have a pic of your meter?
PPM is never a good start, as there are no PPM meters. Yes you can buy meters making the claim, but it's not actually possible. To get ppm you must boil off the water and weigh the debris. These meters just measure EC and guess PPM by non standard means. They came over from fish supplies, and just stuck in the hobby market. We need to see them gone. However lets see it... It can be made it work. It's just a number.

Good morning, Ca++!

This is the pen that I use:
https://bluelab.com/usa/bluelab-conductivity-pen

(I also have an cheapie from Amazon; I just checked and the numbers are close, between them.)

You can easily change the units from EC, to 500PPM scale, to 700PPM scale. And yeah, they're almost certainly doing a conversion/guess.

Point being, I should probably start talking in EC, instead of perceived (and possibly incorrect) PPM, right?

Pics of BlueLab meter from the solution currently in the res:

Pic of Amazon cheapie (only measures "ppm" and micro-Siemens, so I'm showing uS/cm here, which is supposed to be EC times 1000):

 

[LeakyBucket]

Maxibloom powder is easy, and when used below 750ppm can turn out decent flower. No calmag, use a pinch of epsom salt for magnesium and the sulfur helps in the production of terpenes. Usually under $20 for a 2.2lb/kilo bag.

Drop your ppm when physical flower bulking quits... you'll notice a big drop in transpiration rates and overfeeding is rather easy at this point. I usually swapped some res water out for a plain r/o addback until transpiration was nearly the same as before, then try to maintain that till the end.

I have no experience with chillers and do not like 'plumbing' attached to my dwc rubs with airstones. Too many bacterial breeding points like RDWC. Ugh!

Always hung my airpumps in the cold air stream from the a/c unit. That air easily chills the res to below 69F, and usually required an aquarium heater for steady 69F.

Thanks! She's getting worse (slowly) , so I'm going to swing by my local hydro shop and grab some Maxibloom powder. And I already have a lot of Epsom salt, but I'll double-check to ensure there aren't any additives. Easy enough to find some if not.

I'm not excited about a nute change mid-grow like this, but it's absolutely gonna have to happen. I'm not giving up on this one; I'm either going to straighten this out (with y'all's help), or kill it trying (which, obviously, I'd rather avoid).

What EC should I run the Maxibloom at? 3 week old plant... I'll check the charts and ask the hydro shop guys, but I wouldn't mind your input. My current solution is 1.1 EC at 5.9 pH (slowly drifting up).

I like the pump-in-AC-vent idea. I just wish I were able to do that, because adding more bacteria havens by way of a chiller is not the optimum approach, plus adding more leak opportunities, failure points, and on and on...

Thanks!