Phosphorus deficiency?

[Doogal]

Hey all
I have ran into a little problem with my Chem City Blues from Mephisto.
From information I could find online, it seemed most likely to be a phosphorus deficiency, but I wasn't 100% sure so thought I would ask.
I would say it started around 5 days ago, at which point I started to give slightly more green planet massive along with the regular feed. It has started to spread a lot recently.

-Problem: browning, bronzing and drying of leaves.
-Medium/grow method: soil
-Feed and supplements used:
remo velo kelp 1.5ml/L (1-1-1)
GP Massive 2ml/l (1-2-3)
GP Liquid w8 1ml/l (0-0.0005-0.069)
sensi bloom a 2ml/L (3-0-0)
sensi bloom b 2ml/L (2-4-8)
-Water source: Tap water
-Strain and age : Mephisto Chem City Blues. 48 days old
-Climate: 24-26 day 16-18 night (in degrees celsius)
- Light used: 600 W HPS . 20/4 . 2 foot above canopy
-Additional info: It started around 5 days ago, very minimal, and I think it was mainly the lower leaves but it has worked up to the higher up leaves and has spread a lot.

--Pictures


Would really appreciate any kind of help, thank you lovely folks

 

[Rev. Green Genes]

It could be a high pH, it could be deficient. It's pretty thick in there too, I would prune out some inner lower fans, take out the ones that face the main stalk first from the bottom.

To know for sure you've got to do a pH test. Either a pour through with a pH pen, or a soil measurement with a probe is best.

 

[Doogal]

Thanks for the reply @Rev. Green Genes
I'm using Sensi Bloom which is pH perfect, but I also check my pH after I've finished mixing everything up every time and for the last 4-5 weeks now and haven't had any issues as the sensi pH perfect stuff has been doing its job in automatically ph'ing the mixture.
When my lights come back on I can check the run off and see what that is like.

 

[namvet25]

Have you been using cal/mag?

 

[Doogal]

Have you been using cal/mag?

I have yeah mate, I forgot to add it to my nutrient list. I have soft water here, so I've been adding cal mag to every single feed from day one. I'm using AN Sensi Calmag xtra.

 

[Maljross]

I'd say ph
And correct me if I'm wrong as I don't have a bottle in front of me but I use the sensi bloom ph perfect and it suggests RO water or about 100 mb 200 ppm water
My taps just under 300ppm and I still ph down
If your run off high might be salt built up which does raise ph from my experience
My 2 cents hope it works out
Lovely ladies you got there
Stay lifted


Sent from my SM-G935P using Tapatalk

 

[Rev. Green Genes]

It was a great dis-service to new growers to claim pH is magically stable. It's just basic chemistry, anything added or removed from the soil environment changes it's pH, and because of that; it changes what forms of elements are available to the plant. They can only guarantee that it behaved in a test environment.

 

[Doogal]

Thanks for the reply guys.
I am with you on the pH. What would be best to do here?
Just feed plain pH water for the time being?
Or add all my other nutes and not sensi bloom and pH it to 6.3?
Really appreciate the help too

 

[Rev. Green Genes]

I'm a little to flaky to remember the procedure, so I'll copy it from Waira here:

1. water containers to saturation (so that a few drops of water come out of the bottom of the container) with the normal irrigation water they have been receiving... do not use a nutrient solution, it will badly skew the results...
2. after container has drained for one hour, place a saucer under the container -- make sure to use a clean, uncontaminated container- any residuals in dirty one will skew the readings,....
3. pour enough distilled (DI)/RO water on the surface of the container to get about 50 mL (1.5 fluid ounces) or so of leachate to come out of the bottom of the container (Table 1)
4. collect leachate for pH and EC testing;
5. calibrate pH and EC meters, if not done recently
6. measure pH and EC of samples, then do this calculation-->

-- Calculation ->>> If your runoff pH is higher than your starting (water) pH, use this equation to determine your soil pH:*
Soil pH = Runoff pH + Difference

--- If your runoff pH is lower than your starting pH, us this equation:
Soil pH = Runoff pH - Difference.

For example, say your the starting pH of your solution before it goes in is 6.5 and the pH of your runoff is 7.0. The difference is +0.5, so using the above equation:
Soil pH = 7.0 + 0.5*
Soil pH = 7.5

If your starting pH is 6.5 and your runoff is 6.0, your difference is -0.5 and using the above equation:
Soil pH = 6.0 - 0.5
Soil pH = 5.5

 

[BII]

pH Perfect involves the nutes being in stable chelated forms in solution so that they are available to the plant over a wide range of pH. pH Perfect does not directly function to adjust the pH. Adv. Nutr. (and basic chemistry) advises against adjusting the pH with pH Perfect base nutes, with this just adding more salts/ions that eventually degrade the pH Perfect activity/potency.

Where do people get this idea about need to adjust pH if using pH Perfect? Just follow instructions, which never mention adjusting feed pH. You should be concerned about the salts/ions/ppm/EC level of your water (should be low) rather than adjusting pH.