Chemdog with a Deficiency Please help Identify

[Miggs]

Hi Farmers. This is my lone Chemdog girl. She is at 18 days of 12/12 and I just noticed this on her today. It is on new growth as well as old. Purple in the leaves... Phosphorus?

Soil Growers:
1. Are you growing from seed or clones? Clone
2. How old are your plants? 18 days of 12/12
3. How tall are your plants?3'very
4. What size containers are they planted in? 5 gal smart pots
5. What is your soil mix? Promix
6. How often do you water and what type of water do you use? Tap water every 5 days
7. What is the pH of your water? feed at 6.1-6.3
8. What kind of fertilizer do you use and what is its NPK ratio? Hydro-grow 4.5/16/34 Potassium Nitrate 13/0/44
9. Do you foliar feed or spray your plants with anything?No
10. What kind of lights do you use and how many watts combined? (HPS, MH, fluorescent, halogen, incandescent "plant lights") 4 x 1000w Eye Hort Super HPS. Phantom Dimmable ballasts
11. How close are your lights to the plants?18-24"
12. What size is your grow space in square feet? 10x12
13. What is the temperature and humidity in your grow space? 80 54% and 70 50%
14. What is the pH of the soil? Run Off Ph of this plant today was 5.9
15. Have you noticed any insect activity in your grow space? None
16. How much experience do you have growing?1.5 years
17. CO2 at 1350ppm

 

[Green Mopho]

Classic magnesium deficiency. Add some MgSO4 to your nute regiment.

 

[Natural]

when did she start losing her green? I always gave Chemdog lots of N and a lil Mag through to 2.3-3 weeks of flower. have you checked the roots for bugs?

 

[Seamaiden]

Quick way to determine for sure if it's Mg is to do a foliar with MgSO4 at the rate of about 1g (1/4tsp) to 1gal water+adjuvant/surfactant (soap, JMS Stylet oil, SM-90, anything like that). If it greens up within a few hours, that's the tell.

 

[Miggs]

Whats a good PH for the foliar mix?

 

[alpinehi]

If it is a Mg deficiency the effects would be most visible on the old growth as magnesium is a mobile nutrient.

 

[We Solidarity]

mag deficiency shows more on new growth in flower, and it shows in different ways. New growth gets the yellow on the outside of the leaves in flower and on really old moms, and it'll show slight interveinal chlorosis on middle leaves in veg. I see both signs in that pic - which leads me to believe you were lacking it in veg and now that the plants are really putting on flowersets it's REALLY lacking. Mag sulfate will definitely help.

 

[alpinehi]

mag deficiency shows more on new growth in flower.

I don't believe that to be true. I pulled this from Cornell University's 'Basic Concepts of Plant Nutrition'

• The mobility of a nutrient in the plant determines where deficiency symptoms show up.​
  • Nutrients that are mobile in the plant will move to new growth areas, so the deficiency symptoms will first show up in older leaves.​
  • Nutrients that are not mobile in the plant will not move to new growth areas, so deficiency symptoms will first show up in the new growth.​

"As new leaves develop, they will take the nutrients from the old leaves and use them to grow. The old leaves are then left without enough nutrients, and display the symptoms. The opposite is true of immobile nutrients like calcium; the new leaves will have symptoms first because they cannot take nutrients from the old leaves, and there is not enough in the soil for their needs."

Source: http://nrcca.cals.cornell.edu/

 

[We Solidarity]

Now that I've actually read the OP instead of just looking at the pic, I'm convinced this is not only Magnesium, but also phosphorus deficiency.

Up your phosphorus. Notice how dark green your bottom leaves are from the buildup of carbohydrates, as well as purpling of the stems. You'll notice alot more plant health and vigor - lack of P and Mg slows down enzymatic processes significantly. You definitely want to add a magnesium source, and back off of the KNO3 a little until the deficiency improves - too much K+ will fuck with Mg uptake. If you want to keep the nitrogen PPMs up (which you should), I'd recommend using calcium nitrate.

also, I've grown Chemdog, chem-4, chem's sis, and a number of chem crosses, and can tell you that genetic is FOR SURE a heavy feeder, and is the biggest Ca/Mg whore I've ever seen. It will definitely get P deficient pretty fast too, only nutrient it doesn't seem to like getting pumped with is nitrogen.

 

[Seamaiden]

Whats a good PH for the foliar mix?

I don't bother pHing foliars, never bothered with an Mg foliar.

 

[Miggs]

I gave them a foliar at lights out, see what they look like in the morning. Also have some rust spots starting to show up on the leaves today. How can I tell if the Mg is locked out or lacking? They are due for a feed tomorrow. Should I add anything to the normal feed? I usually add cal/mg at 5ml/gal.

We.. at what point do you stop feeding calcium nitrate? I use it at 3/4tsp/gal in veg but never in flower.

 

[alpinehi]

The rust spots to me say K deficiency. Whether it's locked out or lacking can be tough to determine. It appears you use concentrated synthetic nutrients, these can cause build-ups of insoluble salts which can cause lockout. Mixing certain nutrients together can cause reactions that may cause lockout. Old nutrients can precipitate in the bottle which can cause some of the ingredients to form into solids. It sounds to me like you might want to start checking out the many advantages of microbial activity in your medium and find yourself a good recipe for a compost tea. When you introduce and maintain a healthy level of microbes into your medium your system becomes soo much more self containing. IMO the benefits are irrefutable.

 

[Nudibranch]

Now that I've actually read the OP instead of just looking at the pic, I'm convinced this is not only Magnesium, but also phosphorus deficiency.

Up your phosphorus. Notice how dark green your bottom leaves are from the buildup of carbohydrates, as well as purpling of the stems. You'll notice alot more plant health and vigor - lack of P and Mg slows down enzymatic processes significantly. You definitely want to add a magnesium source, and back off of the KNO3 a little until the deficiency improves - too much K+ will fuck with Mg uptake. If you want to keep the nitrogen PPMs up (which you should), I'd recommend using calcium nitrate.

also, I've grown chemdawg, chem-4, chem's sis, and a number of chem crosses, and can tell you that genetic is FOR SURE a heavy feeder, and is the biggest Ca/Mg whore I've ever seen. It will definitely get P deficient pretty fast too, only nutrient it doesn't seem to like getting pumped with is nitrogen.

Absolutely on point with the nitrogen observation. End of leaves droop downward with a nitrogen feeding schedule when no other strains have showed sighs of stress or burn. Thanks for the heads up on the mag/ cal. You were right. She loves that shit.

 

[Mr Bee]

Classic magnesium deficiency. Add some MgSO4 to your nute regiment.

Was thinkin the EXACT SAME .a wee bit o cal/mag will be just the ticket.