Interveinal yellowing - I think a Magnesium Deficiency

[BFS]

I think this is Magnesium Deficiency, but the other three stains/plant look good

This photo is from a plant just topped. I have been starting to see interveinal yellowing and rust spots for the last week. I am also seeing a little deformity in the leaf tips. The other 3 strains in the tent look good.

• grown from seed
• 22 days old
• Was 6" tall before toping
• ebb and flow - Greentrees Hydroponics Multi Flow
• I was using A/N PH perfect until 6 days ago I did a reservoir change. At that time I switched to Megacrop. It was a previously opened bag of Megacrop.
• PH has been slowly rising from 5.8 to 6.0
• Water was R/O with a PPM of 25
• nutrient solution for the last 6 days has been slowly lowing from 634 originally to 618 now
• no foliar feeding
• Light has been 315 CMH
• Light has been about 26 inches above pots
• Growing at on end of 4x8 tent
• lights on Temp 70, humidity 68 (trying to keep a good VPD)
• lights off drops to 63 degrees and humidity goes to 45%
• No insects seen

I watched a video where Harley Smith said too high of humidity slow transpiration and slows Calcium uptake. Maybe my attempt to keep VPD from getting to high is the cause.

Thank you in advance for your attention and help.

 

[RR1]

I think this is Magnesium Deficiency, but the other three stains/plant look good

This photo is from a plant just topped. I have been starting to see interveinal yellowing and rust spots for the last week. I am also seeing a little deformity in the leaf tips. The other 3 strains in the tent look good.

• grown from seed
• 22 days old
• Was 6" tall before toping
• ebb and flow - Greentrees Hydroponics Multi Flow
• I was using A/N PH perfect until 6 days ago I did a reservoir change. At that time I switched to Megacrop. It was a previously opened bag of Megacrop.
• PH has been slowly rising from 5.8 to 6.0
• Water was R/O with a PPM of 25
• nutrient solution for the last 6 days has been slowly lowing from 634 originally to 618 now
• no foliar feeding
• Light has been 315 CMH
• Light has been about 26 inches above pots
• Growing at on end of 4x8 tent
• lights on Temp 70, humidity 68 (trying to keep a good VPD)
• lights off drops to 63 degrees and humidity goes to 45%
• No insects seen

I watched a video where Harley Smith said too high of humidity slow transpiration and slows Calcium uptake. Maybe my attempt to keep VPD from getting to high is the cause.

Thank you in advance for your attention and help.

Some strains eat up calcium and magnesium like nobodies business. I always make sure I have an abundance of both. One thing I also do is foliar feed with 1 tsp magnesium sulfate (epsom salts) to 1 gal water, once a week. They sure seem to like it. Do you use a cal/mag product? It's cheap insurance.
Good luck,
RR1

 

[BFS]

I have a bottle of GH CaliMagic so I just added ~2 ml/gallon. That pumped the TDS up to the 760 range. Hope that does the trick.

 

[BFS]

After adding the Calimagic I did some calculations and determined that I was probably at 24ppm of Mg with the original Megacrop at 4 gms/gallon 650ppm on a 500 scale.

Adding 2 ml /gallon of CALiMAGic was going to add a pitiful 9 ppm of Mg.

I added 1.2 mg of MgS per gallon and that should put me at 72 ppm. Compared to a Jack321 which comes in at 88 at full strength.

That was done on the evening on the 8th. I had hoped properly addressing a mobile element in hydro, that the problem would go away quickly. It has been two days.

New pictures show not so much.

Thoughts?

 

[GNick55]

way over watered!

 

[GNick55]

way over watered!

you have wash/clean that medium before using it? somethings happened, root issues now.. i’d start over..

 

[BFS]

way over watered!

hydroton ebb and flow?