plants burning with a very low ppm

I'm about to start week four of flower in deep water culture.
using general hydroponics 3 part flora series.

The plants have been pretty happy for the most part until I introduced 1/2 dose of AN big bud. The plants started having a deficiency from too much phosphorus. Flushed for 2 days in straight ph water.
I went back to half nutes and they are starting to have nute burn at a ppm of 400. Seems odd when most people have at least double the ppm's.

The problem is that I'd like to start week 4 using bloombastic. But with the ladies burning at a low ppm and couldn't really handle the big bud additive, how will I even get them to take up some bloombastic?

Has anyone had a successful harvest that was a good one using a low ppm like me?

Growing blue dream and og kush. 600w in a closet. Plenty of air circulation and RH is 30-50 with air temps always under 79 degrees.

Avoid anything "organic" in the nutrient water, that means extracts, vitamins, acids, and definitely no Carbohydrates (sugar). Organics feed brown slime algae as well as pythium "root rot". A simple pure synthetic (chemical) nutrient formula

look at roots what you see ?

S13hitman said:

Has anyone had a successful harvest that was a good one using a low ppm like me?

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Yes, I have, and with half of that ppm being from tapwater already. It's what I consider normal, not low. The ppm should drop slowly (like 10-40 per day) or at least not climb. It differs per setup and strain, the number itself is only high or low compared to the plant's demands and what others use isn't that relevant.

I've learned to feed based on the ppm's rising or lowering but now they just keep climbing up and ph dropping quickly.

Is bloombastic organic? Because I see a lot of people using it with hydroponics. Or big bud. .

S13hitman said:

I've learned to feed based on the ppm's rising or lowering but now they just keep climbing up and ph dropping quickly.
Is bloombastic organic? Because I see a lot of people using it with hydroponics. Or big bud. .

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not for deep water culture
Bloombastic® contains at least 50% more phosphorus and potassium than competitive bio-stimulants. Contains sea kelp and clay minerals that make it organic based. Bloombastic® is suitable for all substrates and can be used in hydroponic, soil and coco applications.

Take a pic of plant and roots

S13hitman said:

I'm about to start week four of flower in deep water culture.
using general hydroponics 3 part flora series.

The plants have been pretty happy for the most part until I introduced 1/2 dose of AN big bud. The plants started having a deficiency from too much phosphorus. Flushed for 2 days in straight ph water.
I went back to half nutes and they are starting to have nute burn at a ppm of 400.

Click to expand...

If using gh flora 3 part was working well, why introduce AN big bud? Instead of flushing in pure water for 2 days, it would have been better to start over with a fresh reservoir between 1.2-1.4EC and just use the GH flora the way you were using it before.

2 days of pure water in DWC could cause all sorts of deficiency issues. I keep EC at 1.4 from start (seedling/clone) to finish (cut).