What do y'all reckon?

[darXound]

Calcium deficiency? Phosphorus deficiency? Or something else.....

[Shumroom]

Possibly environmental  

 

Got a diary on the go that you can point us to?

 

Atb

 

 

 

[lildaveham]

@darXound

 

We need more info to be able to suggest anything.

 

Temps, medium, Nutes, watering amount, what light are they under etc…

 

 

[darXound]

Other than being a little cool for the past couple of nights, environment is rock solid (Thanks AC Infinity!)... Temps range from 25 during the day to 21 at night, except for the last two nights where it's dropped a little. VPD is kept in check at 0.9 to 1.15. Light is 600w HPS. Watering is is fairly on point except I have left them a little dry on a couple of occasions.

 

I suspect it's more of a deficiency than anything else. This is my first soil grow so i've not been too confident where the food in the mud ends and the nutes begin. I always feed as light as I possibly can and this time, my starter water has been cleaner than ever. Starting with 0.2 EC, i'm CalMagging up to 0.4, then adding terra vega up to around 0.8 (all Canna nutes). PH'd to 6.2.

 

We are 6 weeks from germination. Two different cultivars, Dinamex at the top with suspected calcium, Critical at the bottom with suspected phosphorus. These are the only two plants out of 8 that are showing signs.

[darXound]

4 hours ago, Shumroom said:

Got a diary on the go that you can point us to?

Not on here but I should start really

 

Cheers

[ratdog]

i'd up the feed, 0.8 is low for soft water ime

[darXound]

1 minute ago, ratdog said:

i'd up the feed, 0.8 is low for soft water ime

Most probably right. I always keep it as light as possible as I say. I am scheduled to re-pot these in a few days mind you, so may just bring that forward to today. I've got some incredibly rich Plagron for them to go in. Main point of this post is to get UK420's collective expertise to identify the deficiency accurately.

 

Not even arsed about the plants tbh. This is a pheno hunt so any Dinamex with weak traits are getting left behind and the Critical was just a freebie 

[lildaveham]

Imo temps need upping about 3c both day and night. Also no need to adjust ph in compost as the compost will buffer the feed. 
 

Pots need to be watered to runoff and not left to dry out too much. Once you have watered them just pick them up and once the weight of the pot reduces then it’s time to water again. 

 

[darXound]

Just now, lildaveham said:

Also no need to adjust ph in compost as the compost will buffer the feed

Interesting. That would sure save me a headache. In that case, would you say i'm doing harm with PH down?

[ratdog]

3 minutes ago, darXound said:

I've got some incredibly rich Plagron for them to go in.

 

 

i assumed you were in coco, so as above, no need to measure ec, just up the feed

 

e2a, forget the ph and ec

Edited February 28 by ratdog

[lildaveham]

1 minute ago, darXound said:

Interesting. That would sure save me a headache. In that case, would you say i'm doing harm with PH down?

Yeah the ph down would throw the ph of the compost out and this may be why you are seeing a deficiency. 
 

You seem to be treating the compost like a coco grow feed wise, this will work to en extent but dropping the ph adjustment should help. 
 

Once you pot up to the plagron (Batmix?) I would just feed plain water for a week, then start on a low feed. Building up the feed as the plant gets bigger. I haven’t used canna nutes for a loooooong while so maybe someone with more recent experience will chime in. 
 

[darXound]

2 minutes ago, lildaveham said:

Yeah the ph down would throw the ph of the compost out and this may be why you are seeing a deficiency. 

Great advice  that could explain the lockout and it sounds more likely than simply underfeeding.

 

3 minutes ago, lildaveham said:

You seem to be treating the compost like a coco grow feed wise

Guilty  it's just what i'm used to at this point

 

4 minutes ago, lildaveham said:

Once you pot up to the plagron (Batmix?)

It's growmix. I got it on a whim as my local hydro store just got it in, and the one I started with (Canna professional) is awful.

 

Will give them a foliar spray before lights on, then repot and feed only water tonight

[inceywinceyspider]

On the vega bottle it says 5ml per litre, that's the max dose, in canna pro or any normal compost with good levels of fertiliser you should wait until the pot is rooted with roots coming  through all the holes at the bottom before starting feed at 2.5ml per litre or less. Read the plants to see if that's too much which is more likely than too little.

Different strains will use different quantities of nutrients, underfeeding normally shows up with lowest leaves paleing and yellowing first.

Unless your water is really off the scale you just need the vega and flores and nothing else for a successful grow.

[Cajafiesta]

@darXound

 

Did you get it figured out?   I've had some revelations in nutrition lately that have REALLY improved the quality of my plants.  I'm certainly no expert, but here's what I've learned/started doing. 

 

 

First- what size are your pots and what is your pot progression? How long are they staying in each pot size and what do the roots look like when you pot them up?

 

What are ROOT temps.  

 

Have a water sample analysis done.  I can't repeat this enough.  You CAN NOT assess what is going on if you don't know the makeup of your water. 

 

Segregate your nutrients.  I stopped using mixed cal/mag products etc.  Adding cal/mag will not improve anything if your starting calcium to magnesium ratio is super fucked up like mine is ( something like 10 or 11:1 in my case)  All you're doing is increasing the quantity of calcium and magnesium while maintaining a ratio of cal-to-mag that may be off.   Once you know your water's ph and cal/mag ratio separate your calcium and magnesium inputs totally.  Find a gpysum (micronized) product for CAl and use Epsoms Salt for MAG.  Both of these can be applied in a foliar applicaton and will allow you to see the effects of the application in a day or two.  You can use it as a fairly quick, visual, assesment.  sort of a " asking the plant if you helped it" visually, and you get a fairly quick answer. 

 

 

I agree regarding not phing soil water input IF it's a rather large pot.  If you're in pots that are, say, sub 5 gallons, I DISAGREE with this.  I've seen it in practice myself and it caused me an immense amount of frustration.  I have somewhat alkaline water and, if I don't PH down when using smaller pots, the plants look like I'm completely incompetent. Phing my water down in small pots and soil has been the most effective way for me to develop a constant and reliably apply scientific method to my growing.  Several growers/breeders I trust well have also described experiencing/figuring this out just as I have.  It seems to be a commonality with well/alkaline water across the board. 

 

 

 

 

Both of those plants, if they were mine, I would be applying calcium. I can't tell you how many plants I've ruined in ignorance due to calcium def.  If this is cal, you can expect those leaves to end up looking pale and covered in brown "rust" spots until, eventually, the whole leaf dies and becomes pale yellow, with all the rust spots morphing into one brown. pale-yellow, dried and crunchy leaf.  It'll spread to the whole plant, eventually, in a severe cal def.  You can apply gypsum to the soil as a top dress or water/foliar gypsum. but it will take time to uptake unless you go the "micronizzed" route.  I prefer micronized as it's much more effective.  I also like a calcium/phosphorous product  called Pcal that is micronized.  Very effective.   I've found that my plants want significantly more calcium than I ever assumed they would.  It seems even more the case using LEDs.   I've had some show cal def from 2 weeks old onwards.  I always watch the cotyledons.  If they start yellowing and looking poor, something is already going on that you need to figure out yesterday. 

 

 

 

I don't see any phosphorous issues there, to my eye.  Phos always seems to coincide with purpling petioles and stems, at least on non-purple cultivars.  Bone meals are high in P.  I have a habit of watering frequently with 1 gallon water, 1Tablespoon kelp meal, 1 Tablespoon alfalfa meal.  A couple times a week.  These seem to help mantain P and K to some degree.  

 

 

Calcium is without question my most commonly chased nutrient.  without question, 100%

 

 

 

 

All of these statements are assuming your environment is somewhere in the ballpark of "reasonable."  your air temps don't strike me as outlandish, but if you're not monitoring root temps, you have to.  There's no way around that unless you live somewhere that's on the equator and it's hot all year round.  

[darXound]

3 minutes ago, Cajafiesta said:

Did you get it figured out?

Yes, turned out to be ph lockout thanks to a terrible ph meter that I seemingly have to calibrate every time I use it. It was reading ridiculously high after a couple of feeds without me knowing so I must have watered at around 5 or below  We all happy and healthy now 

 

7 minutes ago, Cajafiesta said:

I DISAGREE with this

Agreed! Although this comment did point me to the issue. If bad ph in the water can cause such a lockout in the first place, it stands to reason that aiming for the right ph in your water is a good thing, even if the soil is supposedly buffered. My ph generally goes up to 9-10 after i've added rhizo, so bringing it down is pretty important imo.

 

I've also just realised just how much the ph drifts over time once nutes and ph down are added. To fix this, i've started to mix up my nutes, leave it overnight then check again and amend. I'll leave it a few more hours or sometimes overnight again, and only when it's stable i'll water. This is working great so far, but going back to coco next time 

 

Thank you for your comprehensive response. There are some interesting points there