Please Help!

[MSL777]

Hello, newer grower here. I'm hoping someone out there knows whats going on here. I think I have narrowed it down to Potassium or calcium deficiencies. Its late stage no doubt, However, I'm hoping it can be saved. Id like to know how to prevent this in the future . I'm hoping this doesn't ruin anything as I'm only a few weeks from harvest. Thanks in advance

600w vipar
135w HLG quantum board
canna nutes
5 gallon square pots
Soil - 50/50 strawberry fields & happy frog
PH 6.0-6.5
Run Off PH is super low 5 ish
RUn Off PPM 1100
soil PH - unknown

 

[Backlipslide]

Ohh yeah something going on there!

It’s normal for leaves to get discoloured in late flower, but definitely not like that.

It does look like a bit of a calcium def. have you given her a flush through out the grow at all?

Do you have any extra cal mag in your repertoire?

I’m sorry if I missed it but what are you growing in?

 

[Emilya Green]

Ohh yeah something going on there!

It’s normal for leaves to get discoloured in late flower, but definitely not like that.

It does look like a bit of a calcium def. have you given her a flush through out the grow at all?

Do you have any extra cal mag in your repertoire?

I’m sorry if I missed it but what are you growing in?

My thoughts too... salt lockout. FF soils also need the incoming pH pretty close to 6.2 mid to late flower too or you miss a few things. 6.5 is too high... the soil is buffered too strongly to 6.8 and you miss all the drift by coming in too high.

 

[MSL777]

Baclklipslide - Im growing in 50/50 FF strawberry fields and FF Happy frog. I did do a flush about a week ago but its still happening.

Emilya - How can I correct this issue, and how do i keep it from happening in the future?

 

[Emilya Green]

Where do you come in at with your pH?

 

[Emilya Green]

and I got to ask in todays climate.... was it a real flush with 3x the container size in water?

 

[MSL777]

I did about 12 gal per pot.
I put my nutes in and PH at 6.5

 

[Emilya Green]

I did about 12 gal per pot.
I put my nutes in and PH at 6.5

how big are the pots?

 

[MSL777]

About 5 gal square pots. I do understand the 3x the pot size but time and kids got in the way.

 

[Backlipslide]

Yeah that always gets in the way, I feel ya there. Pain in the ass to sit there and do a proper flush, but once done, you won’t regret it.

 

[Emilya Green]

About 5 gal square pots. I do understand the 3x the pot size but time and kids got in the way.

alright, well you got close and I bet you cleared out a lot of the salts with 12 instead of 15 gallons, so good job. Your mistake is a classic one and one derived from all the bad advice that is being put out on some of these forums. It seems to be popular advice to pH adjust each time to 6.5 and not worry about it, since that is the middle of the range. The problem is that some soils, like FF are buffered very heavily to attempt to swing the pH toward 6.8. If you come in at 6.5 every time in a soil such as this, the only range your plants see is 6.5-6.8, and you miss out on any nutrients that are most mobile at the lower end of the range, from 6.2-6.5. This is what you are seeing... a multi-element deficiency, mostly molybdenum and some of the other heavy elements in varying amounts. This is a progressive deficiency that builds in intensity as you get to middle to late flower and it can be avoided simply by coming in at 6.2-6.3 pH at least a few times in mid flower, or a method I like is to pH to 6.3 when applying nutes and then 6.5 when you do the plain water.

 

[MSL777]

Emilya thank you. That was super informative. Im using the dropper and shaker right now for ph testing (my digital one fell and broke) so ill PH to 6.2-6.3 a few times during flower. and 6.5 with plain water. now, this is probably a dumb question at this point but, when should i be using plain water? I feed every time i water. every few days or when my moisture meter says they are dry

 

[Emilya Green]

Glad to help, but now more questions... what feed are you using? The normal way to feed in soil is to feed/water/feed/water, alternating all through the grow. The logic is that on the first pass the plant does not actually use all of the nutes that you applied so you come back with pH adjusted water to reactivate the nutes and give the plant a second pass at clearing them out of there.
Where are you sticking the moisture meter to tell if they are dry? With that meter you should be able to see exactly where the wet/dry line is... how far are you letting it fall?

 

[MSL777]

i put the meter half way between the stalk of the plant and the side of the pot. when the meter says its dry i pick up the pot and feel the weight just to confirm. I completely understand the feed/water/feed/water cycle. makes total sense and will implement immediately. I have been using Canna nutes at half strength. These plants are autos. shoul have probrably said that earlier.

 

[Emilya Green]

do an experiment. carefully place your water meter in and watch it as you place it in 1 inch, then 2...etc and you will see it go from dry to moist and then all of a sudden it will peg out to the WET side of the scale. That wet/dry line is the whole point of that meter... so that you can "see" where the water table is at any moment. When the water table has fallen down into the last inch of your container and that diaphragm that is formed by the top of that underground lake has pulled oxygen way down in to those bottom roots, then and only then is it time to water a vegging plant.

 

[MSL777]

ok that sounds like a plan. I assume its the same for flowering plants?

 

[Emilya Green]

ok that sounds like a plan. I assume its the same for flowering plants?

nope... never assume... especially around a weed. In a flowering plant it is time to use the roots that were developed in veg, and the watering method changes just a bit to see how much water you can get the plants to take.

 

[MSL777]

ok, what exactly does that mean? "watering method changes just a bit to see how much water you can get the plants to take."?

 

[Emilya Green]

You figure out what the daily usage of the plants are, or two day usage, (whatever interval you wish) and then you attempt to force feed that much into the plant on a tight regular schedule, ready to respond if water usage goes up or down while you do this.

 

[BeanTownFan420]