How do people push such high PPM in flower?

Possibly a silly question, but I've been trying to go with less PPM in nutrients over the years and I'm always shocked how little it takes to burn the plants. For example, my last grow only ran about 1/2 tsp per gallon of Dyna gro bloom at peak flower which comes out to no more than 400 PPM (including 210 tap PPM). This already seems like the upper limit for most of my grows without them frying; yet most of the top sources from growing discuss 1000-1400 PPM during flower which sounds absolutely unreal to me. What am I missing? If this represents the absolute upper limit, why are the lower limits not discussed more? What are the minimums plants actually need during veg or flower (obvious variables aside)? I've had a decent amount of success with no more then 400 PPM or so throughout the grow, but I seem to be the anomaly compared to the majority so I'd like some insight if possible.

There ARE a lot of variables.. the strain/pheno's health, a sealed environment with a CO2 generator blasting at 1200ppm, lights, etc. Healthy plants can take more feed ppm's if they are CO2 supplemented, and your lighting is on par (pun intended)

Size of plants is a big factor as well among others

Why do so many growing sources lead with the higher end of the range, especially for beginners?

RuggedWombat said:

Why do so many growing sources lead with the higher end of the range, especially for beginners?

Click to expand...

To sell more product.

RuggedWombat said:

Why do so many growing sources lead with the higher end of the range, especially for beginners?

Click to expand...

What sources? Most of what i have seen is to err on the side of underfeeding because it is much easier to correct.
If you're pushing clones you've ran time and time again, you obviously know what kind of feed they can take and may go for the top end if that is what they like

Do you have any pictures of the plants that doesn't sound right, have you considered other factors like feed regularity, watering, environment etc?

A pic and as much detail about your grow would help us to help you.

Fox Farms Happy Frog
5 Gal smart pots
Dyna Gro nutrients 1/2 tsp bloom fed every other watering
Plants watered twice per week
PH 6.2-6.8
Tap water is pretty alkaline 7.7 or so. Also has about 190-200 PPM before nutrients

All the rest is within range. Temp, RH, airflow is adequate. I've ran Mephisto autos before under almost identical conditions and 1/2 tsp of bloom is usually the right amount about this time in bloom. Let me know if I'm missing something else.

RuggedWombat said:

Fox Farms Happy Frog
5 Gal smart pots
Dyna Gro nutrients 1/2 tsp bloom fed every other watering
Plants watered twice per week
PH 6.2-6.8
Tap water is pretty alkaline 7.7 or so. Also has about 190-200 PPM before nutrients

All the rest is within range. Temp, RH, airflow is adequate. I've ran Mephisto autos before under almost identical conditions and 1/2 tsp of bloom is usually the right amount about this time in bloom. Let me know if I'm missing something else.

Click to expand...

The solution is that you are starting with a rich source of nutrients as your base. One that's known to burn young plants all by itself so it doesn't take a lot of added fast-food type nutrients to push it into the burn zone.

If using a soilless medium that has no nutrients of it's own, like ProMix HP or straight coco, then what you feed yours would rapidly starve a plant.

Watering twice a week sounds a bit much unless these are big plants and can dry down 5gal in 3 - 4 days.

RuggedWombat said:

Possibly a silly question, but I've been trying to go with less PPM in nutrients over the years and I'm always shocked how little it takes to burn the plants. For example, my last grow only ran about 1/2 tsp per gallon of Dyna gro bloom at peak flower which comes out to no more than 400 PPM (including 210 tap PPM). This already seems like the upper limit for most of my grows without them frying; yet most of the top sources from growing discuss 1000-1400 PPM during flower which sounds absolutely unreal to me. What am I missing? If this represents the absolute upper limit, why are the lower limits not discussed more? What are the minimums plants actually need during veg or flower (obvious variables aside)? I've had a decent amount of success with no more then 400 PPM or so throughout the grow, but I seem to be the anomaly compared to the majority so I'd like some insight if possible.

Click to expand...

Fellow Bloom user here. 400ppm during flower sounds about right.... even less at the very end. I love the simplicity of DB.... pour and stir.

OldMedUser said:

The solution is that you are starting with a rich source of nutrients as your base. One that's known to burn young plants all by itself so it doesn't take a lot of added fast-food type nutrients to push it into the burn zone.

If using a soilless medium that has no nutrients of it's own, like ProMix HP or straight coco, then what you feed yours would rapidly starve a plant.

Watering twice a week sounds a bit much unless these are big plants and can dry down 5gal in 3 - 4 days.

Click to expand...

Funny enough I will be switching to pro mix HP for my next grow for that exact reason: blank slate. However, I was always led to believe happy frog had maybe 2 weeks worth of food in it? Ocean forest is a different story. They actually dry out a bit faster than 3 days even so I could be watering more. If I wait one day longer, the plants will be drooping/wilting. I think the 3 GAL size paired with being an air pot just dries them out crazy fast. Idk what I was thinking going with 6 3 GAL when I should have done like 3 10 gal pots. At this point I'm guessing my best option is cut to around 1/4 tsp bloom per gallon? Other option is keep the 1/2 tsp but add two waterings between feedings versus one. I may just run FP start to finish on my next grow for simplicity's sake. It's also hard to rule out PH sometimes as it seems like soil is a very poor PH buffer later in the grow. I PH my water correctly, but I can't shake the suspicion that the nutrient/ph down mixture absorbs at different rates, causing the actual soil PH to be driven lower than the PH of the water going in. I suppose some soil slurries could confirm?

MrFlatbush said:

Fellow Bloom user here. 400ppm during flower sounds about right.... even less at the very end. I love the simplicity of DB.... pour and stir.

Click to expand...

I run my EC relative low in general, but 400ppm in flowering sounds too low, and runs a risk of having deficiencies.

PJ Diaz said:

I run my EC relative low in general, but 400ppm in flowering sounds too low, and runs a risk of having deficiencies.

Click to expand...

"And that, little Jimmy, is how new threads are born."

I think temps and humidity also play a big role. If it's hot and dry, the plant is gonna need more water, but roughly the same amount of nutrients (total quantity, not ppm). So everything else being equal, you would feed at a lower ppm in a hot and dry environment than you would in a cool and humid one, and the plant would use more water but get the same amount of nutrients.

PJ Diaz said:

I run my EC relative low in general, but 400ppm in flowering sounds too low, and runs a risk of having deficiencies.

Click to expand...

Problem is nutrient burn continues to spread when feeding just at the 400 range. It's also possible the lights are due for an upgrade. They are already pretty weak being 2x HLG 100 R specs (not to mention they are now 2 years old). If the plants can't eat the nutrients fast enough then even 400 will be too much.

Here were the plants on 9/22, 10/1 and 10/7 for comparison.

RuggedWombat said:

Here were the plants on 9/22, 10/1 and 10/7 for comparison.

Click to expand...

They look hungry to me in the 10/7 pic. I think some of what you're seeing might be windburn, with that fan blowing right at the plants so close.

Here are some updated pics. I still don't think they are deficient as the new growth continues to show signs of burn as well as the undergrowth still being overall mostly healthy looking. I don't see a lot of textbook signs of N or P loss (no yellowing from the tips inward, yellow wilting, no purpling of stems). The splotching is hard to tell if it's P but as silly as it sounds I feel like 350 PPM or so is already pushing it. They are due to finish at the end of the month so at this point I guess finish with what I have and hope they fatten up. I'm not seeing a lot of bud swell yet and pistils are already turning orange on some parts yikes.

Well we can guess all day what it is or not…. But until you do a slurry and see what the #s are , we are just guessing …..

Tbh I don't see any burnt tips on the new growth. Are you sure it's not a potassium deficiency? I know that can look similar to nute burn, and I wonder if the typical symptoms of "nute burn" is actually potassium and calcium getting locked out..