Brown spots and curling tips on multiple plants

[Dr666]

Soil or hydro: Soil
plant age: 2 months since I started to germinate the seeds.
pot size: 11l
has it been repotted? and when?: yes, several weeks ago
soil type: BioBizz Allmix
nutes or additives used and how often for soil: BioBizz grow 1ml/l since about 3 weeks ago. I feed once a week.
temps (max min): 20-27C
humidity: 55-65%
lighting type: 400W HPS (Osram Plantastar) in cooltube, about 20cm away from the plants.
ph level: NA

Hey!

I'm growing 4 different strains in a wardrobe. SLH, C99 Blue Cheese and NL. I'm ready for flowering, but I want to correct any potential problems before I start.

I had/have a problem with Mg and Nitrogen def. I have started to correct it with most plants, I added 1ts of epsom salt and calciumsulphate to 5 liters water couple of weeks ago. I know from my aquarium hobby that we have soft water where I live. So I thought I could also have a Ca def, that's why I added the calciumsulphate.

Can someone please help, this is my first grow so I'm really unsure about what the problem is.

(PS. The pictures were taken right after watering, so they look much more droopy then normal)

Pictures:

C99:










SLH:






BC:








NL:

[northenlights]

Rust, cal,mag deficiency. I'd take all effect leafs of as it is mobile and can spread , id give some cal/mag in your next feed or if not feed yet give it a little in your next water What nutrients you using ?

[Woody J]

That looks like out of the box, standard P def to me.
What is your runoff ph?

P def's in veg are unusual, unless the ph is out.
https://www.thctalk.com/cannabis-foru...phorus-%28P%29
This link tells you more about P.
W

[Dr666]

Hmm, so first step is to measure the PH and make sure that's correct and add more Epsom + Calcium?`

I'm pretty sure my girls starved a bit so I could add a larger dose of nutes, next watering.

[Dr666]

Ok I checked PH today, runoff is 6.5, soil sample mixed with distilled water is between 6.5 and 7.0, closer to 7.0. And my tap water is 7.5.

I removed all the damaged leaves and gave the plants this weeks feed which contained this time of BioBizz 1.5ml/l grow, 0.5ml/l bloom and 0,5ml Top Max.

Any suggestions on what to do next, should I spray with some water and epsom salt?

[budstud]

Dr666:

You definitely have a Calcium deficiency. You can foliar feed your babies with one teaspoon of dolomite lime in a quart of water and one to two teaspoons in a gallon of water about two times to get the lime down to the roots (slower acting, foliar feeding will show faster results). Be careful because lime ups the PH so you'll need to be vigilant, that's why I thought is unusual with your initial post, you said PH was n/a.

[budstud]

BTW: I'd attempt to keep the PH around 6.5, that way you're less like to suffer from Manganese and iron def., and it appears your ladies need some magnesium, a little epsom will take care of that, but only in minuscule amounts, maybe 1/4 teaspoon per gallon for one to two feedings unless you've taking other steps to rectify that situation.

[budstud]

I apologize for continually posting but I remembered something else. Anytime you're growing in soil you should always add at least one to two teaspoons of dolomite lime to your soil mixture per gallon of soil, it'll help keep it stable to help avoid any def's.

[Woody J]

Could I explain why this is NOT an Mg deficiency.
Mg is essential to the photosynthesis process, without it, the plant cannot photosynthesise, so when a plant is deficient, the leaves pale due to the lack of photosynthesis, however, the veins stay dark.
The leaves that are yellowing all have pale veins to go with the leaf matter.
Where there is some striping, it is accompanied by necrotic patches, not yellowing.

Therefore this cannot be an Mg def.

Your ph is good, so the issue is down to environment or feed levels.
The more I look at this, the more I think you need to increase the level of feed. This doesnt have to be 3 or 4ml per l, just go feed, water, feed, water for a week or 2 and see how they respond.
A drop of superthrive or big bud or similar with each l of water and removing any leaves more than 50% damaged should see some improvements.
W

[budstud]

Plant Pathology Circular No. 354 Fla. Dept. Agric. & Consumer Serv.
July-August 1992 Division of Plant Industry
MAGNESIUM DEFICIENCY OF FOLIAGE PLANTS
J. J. McRitchie
1
Symptoms of magnesium (Mg) deficiency are among the most widely observed nutritional problems in Florida foliage
plant production (1,2). Magnesium is a key constituent of chlorophyll, the green pigment in plants which is responsible
for phytosynthesis. It is also active in enzyme systems (4). Soilless artificial growing media frequently used in Florida are
low in Mg, requiring a fertilizer program supplying Mg. Many plant nutrients are readily leached from Florida's sandy
soils (3).
SYMPTOMS: Magnesium, not to be confused with manganese (Mn), is easily translocated within the plant (4). It is
preferentially moved to rapidly differentiating terminal areas of the plant; thus deficiencies are evident in older leaves
first. Calcium in plants exists in a sensitive balance with magnesium and some other nutrients. What appears to be an
excess of calcium may be the result of a lack of magnesium; whereas, an apparent excess of magnesium may respond to
the addition of calcium (4).
In most foliage plants, chlorosis progresses inward and downward from the upper leaf margins, leaving an inverted Vshaped green area at the leaf base and a V-shaped area at
the leaf tip (Fig. 1). Eventually, rusty brown necrosis
begins where chlorosis was first apparent. The chlorosis
which develops is a bronze yellow color giving Mg
deficiency the name "bronzing disease" (2).
Many of the foliage ornamentals with pinnately veined
leaves (such as Philodendron scandens subsp.
oxycardium) and the palms (such as
Chrysalidocarpus lutescens) exhibit this
symptomatology (1,2).
FERTILIZATION: Foliage plants have high requirements
for calcium (Ca) and Mg (1,2). Both are available in
dolomite, which is slowly available and should be added
to the media. Tissue levels of 0.35 to 0.50 percent dry
weight Mg should be maintained (2).
SURVEY AND DETECTION: Look for an inverted Vshaped green area at the leaf base surrounded by a
chlorotic area.