Flowering Plants Keep Dying...And pH BS

Been growing a while now and have never had plants just start dying. They look great going into flower, then at about week 4-5 they just start dying from the bottom up.

25 gallon res. / starting water 12ppm(.5) - pH 7.9
BLOOM:
Silica @ 1mL/gal
Foliage-pro @ 4ml/gal
Mag-pro @ 2mL/gal
Alaska bloom 0-10-10 @ 1mL/gal
Comes out to around 700-800ppm

VEG:
Silica @ 2mL/gal
Foliage-pro @ 2mL/gal
Mag-pro @ 1mL/gal
300-400ppm


Brick coco(GH or mother earth) and perlite. Veg plants go from #1 pots into #7 pots, day 1-5 of flower. I don't rinse, or buffer or any of that shit. I don't have the kind of situation where I can move around a bunch of water to do that. I understand this can be part of the issue, but I have been using these brands and method for 10+ years. So I am fucked up why this is happening.

pH pen is stored in KCI solution and is calibrated @ 2 points. Reading against drops read in the same range.

When I mix my bloom res. the pH sits at 6.2, till the next day. When it's in the 3s and 4s. wtf? I'll raise it to 6. And next day, same thing, or not. Sometimes it'll hold strong overnight, sometimes not. pH up I've used. GH, AN, pure potassium hydroxide, potassium bicarbonate.

I will say it has been hot, dry and smoky these past few weeks or so. The max I've seen in the tent is 86f. Yikes, but not crazy crazy. There is good air flow at the bottom and top of the tent. Passive input with exhaust in the tent. Fresh air comes from within the home and a passive input from outside.

Not really sure what to do at this point. Just pH water flush, I guess. But not sure if that's just going to add to the issue, as I don't know what the issue could be.

Can't tell shit from the images but thought I'd post them anyways...

The heat is over for the year and its cool temps from here on out. I am hoping this to be my saving grace. But idk.

And help is much appreciated. Thanks

When you say your rez pH drops is that just sitting there waiting to be used on your plants or are you doing some sort of circulating grow and this happens while the mix is being used?

Seems odd to be using the alaska bloom with the other stuff but I gather you've done this before successfully? I'm growing in ProMix HP with organics like manures and Gaia Green dry nutes while supplementing with AN 3-part, Big Bud and other more hydro related additives and tho it's been bumpy I'm gradually getting it dialed in as I move to more organic growing after 20 years of DWC and hydro only with ProMix.

Like peat coco is acidic as it breaks down I believe so when using brick coco charging it with loads of CalMag seems to be standard practise from all the stuff I've read about it. I tried that stuff 20 years ago and it killed my plants and it was years later I found out it was probably loaded with salt and needed to be rinsed very well while monitoring the PPM of the runoff to get all the salt out. A while ago I bought a bag of supposedly pre-rinsed and treated coco but haven't got around to trying it yet. Cost almost 3X as much as the ProMix and is a 2 hour drive to get it while I've been able to get the ProMix locally for years and years.

I notice your plants are pretty tall looking and wonder if it's just lack of light to the lower reaches causing older fan leaves to die off. It's happened to me plenty so I get rid of all that stuff before flowering as trimming popcorn buds sux. Your nute mix doesn't seem excessive or I'd suspect toxic salts buildup which I have lots of experience with too. Very low RH here and that makes it happen really easy with just a bit too much feed.

OldMedUser said:

When you say your rez pH drops is that just sitting there waiting to be used on your plants or are you doing some sort of circulating grow and this happens while the mix is being used?

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Good question. Its a 25gal tote with a submergible pump I use for watering, and a really small power head mixing too. The sub pump stays running all the time.

I just use the Alaska bloom stuff cause its added pk.

The picture must be misleading cause the bottom 3 ft of the plant is striped. 450w of lm301 and 120w of lm281 in a 40inch x 40inch tent. Should be plenty of light.

NeWcS said:

Good question. Its a 25gal tote with a submergible pump I use for watering, and a really small power head mixing too. The sub pump stays running all the time.

I just use the Alaska bloom stuff cause its added pk.

The picture must be misleading cause the bottom 3 ft of the plant is striped. 450w of lm301 and 120w of lm281 in a 40inch x 40inch tent. Should be plenty of light.

Click to expand...

Should be but how far away is the area affected from the light? I use a crappy little light meter to check intensity at various distances to make sure the plants are getting the max they can handle at the tops but even with my 600 and 1000W HIDs lower leaves in the shade still end up yellowing and dropping off some.

As these leaves go bad are they yellowing fairly evenly and going all soft and limp or turning different shades of brown and yellow randomly across the leaves and getting thick and brittle?

In the first case that's a redundant leaf the plant doesn't need any longer so it strips it of mobile nutes and it just dies. In the 2nd case it's more the toxic salts buildup I mentioned. That tends to start about mid flower and gradually spreads upwards until even the little sugr leaves start browning out and going crispy. That's caused by even slightly overfeeding thru the plant's life where salts keep getting stored in the leaf tissues until it literally cooks them from the inside out. Higher ppm water contributes to the problem as well.

Still odd that you pH drops like that. Have you tried mixing up a batch without the 0-10-10 to see what happens? I'd invest in some Big Bud for your extra P/K. It's 0-15-35 with 10%S, 20 amino acids and a few other goodies. Very compatible with your other salt-based nutes too. I've used it since it was invented and hate to grow without it tho going to be trying organic equivalents too.

Next res change I'll stop with the fish bloom. Once I get shit back on track I'll look into Big Bud. I don't wanna add shit till I get this figured out.
Thanks for the help.

I get the powdered BB and use it about half strength starting a week before I flip to flower. The powder has a lot longer shelf life so even a small jar lasts me 2 or 3 years. I got a 500g jar years back and it got past it's overdue date when I still had 1/3 left. Still using it tho have some fresher stuff too now.

I have some of the same type of stuff of boost. MKP. moab