Fan leaves degrading during early flowering.

Hi, I'm after a little bit of support if I'm heading in the right direction for curing my issues.

x2 Auto pounder with chesse
Growing in coco coir pro plus 60%/40% perlite.
600watt HPS running @ superlumen (660watt)
15L airpots
20/4
Temps top out at 29/30 C and bottom out at 22/23 C in lights off.
Humidity is static between 49% and 52%
Feeding Bio grow/bloom/topmax
Supplementing with CalMag at 3ml per litre due to coco being notorious with needing this boost.
In 2nd week of flower now and it appears to me that they have taken an adverse vreaction to me feeding them the bloom and topmax nutes.

PH is around 6.4 (I'm going to test run off again tonight as I don't have consistent readings for this as of yet.)
EC has always been high all through veg which they seemed to love (1800). Thinking the bloom and topmax may be too harsh though, so I've dialed off giving them the same amounts and just running water and calmag until they seem to settle.

Anyhow, thats the back story.
Leaves are crisping up and getting rust spots (no residue comes off when rubbed which leads me to believe nute burn/lock out).
Seem to be getting progressively worse, so as I say, I'm only running tap water and calmag to 780ppm (my tap water is 360 - 400ppm and 7 PH).

Am I doing everything I should be or can I do more to help them out this phase. i'm aware that the fan leaves wont recover, so I want to ensure what is left is getting what it needs.

Also don't mind the micro plant in the second picture. It was an experiement that I was toying with. Trying to see how much you can yield off of a micro plant. Will post the results of that when I harvest

Maybe backoff on the calmag mate. 3ml per litre sounds like a lot to use with your tap water being quite hard. I use 4ml per gal (3.8 litres) and my water is soft (28ppm).

It does look like calcium and magnesium deficiencies in your pics. But that dose of calmag sounds like way too much.

EDIT: Forgot to add, if you are using buffered coco, you may not even need calmag. I'd stop using it and see how it goes. Your tap water may already have what the plants need.

I'll just run tap water and go to 1ml topmax and bloom per litre and see what happens then.

I was just conscious that calmag must be used. But figured 3ml was fine as used it all through veg like that.
Soon as I switched to bloom nutes, shit started to fall apart.

Yeah mate give your girls a good flush with 1/2 dose of nutes (minus the calmag), continue your regular feeds without calmag and see how they react.

There's no way you're lacking in calcium and magnesium so something is causing lockout by the sounds of it.

Take a look at this, it may help.

I've been through this several times and it always has me running round in circles.

I was led towards cholrine as a potential cause early on. But this doesn't appear to be the case as the leaves appear to be burning holes through them.
So then the next obvious sign was magnesium deficiency. But that makes no sense with the calmag dosing I've been using.

My next step would be something that immitates mag deficieny which could be phosphorus OD. But I have no idea how to counter that.

So yeah. Am chasing myz arse and starting back from square one.

Soo checked my run off for PH and PPM.

PH comes out at 6.8 and PPM at 1040.

I've just gave them a very light feed. I'll do a proper flush until my PH is down tomorrow morning during lights out. I reckon PH being that high is causing a lockout.

Make sense?

Cornishi said:

Soo checked my run off for PH and PPM.

PH comes out at 6.8 and PPM at 1040.

I've just gave them a very light feed. I'll do a proper flush until my PH is down tomorrow morning during lights out. I reckon PH being that high is causing a lockout.

Make sense?

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At that ph you would be in danger of locking out Manganese and Iron.

I would look at Manganese def symptoms as that looks similar. Just my opinion!

Phosphorus deficiency is setting in. It could be because your pH seems a bit high.

Best of luck.

Manganese does look like it would make sense.

Seems I'll attempt to salvage her as best as I can in the morning. A good flush will probably bring her back in line.

Strange that my PH has spiked that much, I have been very cautious to calibrate my meter every few days to ensure this didn't happen.

HookahsGarden said:

Phosphorus deficiency is setting in. It could be because your pH seems a bit high.

Best of luck.View attachment 3536460

Click to expand...

Phosphorus locks out below 6.5 ph or if there is an excess of Iron, Potash, calcium or zinc.

Think I have been under dosing nitrogen also. Hence the plant turning more yellow. Flushed through and PH is stable at 6.5 currently. Little higher than I'd like but I don't want them to think they're living in a swamp.
Began dosing in some high nitro nutes at a reduced dose. think that may help now with the reduced PH (potential manganese lock out) and less nutes (bloom nutes seemed to kick them for shit even though they loved 2k ppm all through veg).