Does this look like Magnesium deficiency?

[WhiteyBulger]

Thanks for looking, really appreciate any feedback. See images below.

I'm scratching my head, I feel like I am doing everything right, but obviously not.
I have grown five grows. The first two went off without a hitch. The last three I am having these leaf issues that look like a magnesium problem.

Grow specs:
Straight Promix. Gaia Green dry amendments.
6.5ph. / 1.0 VPD / my feed water is well water run thru a water softener and the EC is .13 / TDS 189
I just started foliar spraying with epsom salt everyday thinking it's a Magnesium issue but it may be too late.

 

[Zill]

WB,

Sure looks like a mid stage Mg deficiency. Make a very dilute solution of Epsom sales (1/4 tsp/500 ml spray bottle). Spray to run off. If it’s Mg deficiency the spray will correct that quickly. Then you’ll know.

 

[LoveGrowingIt]

The foliar feed should show improvement within a few days. If the foliar feeding hasn't shown an improvement, then it could be something else. My guess is a lockout condition. Calcium and potassium can inhibit the uptake of magnesium. Phosphorus and nitrogen are synergistic with magnesium. So, perhaps increasing either of those might help. I'd try phosphorus by amending Gaia Green Power Bloom, which is high in phosphorus or foliar feeding a high phosphorus liquid nutrient.

 

[Zill]

Good stuff!

 

[Imzzaudae]

Top dressing these plants with tablespoon each of Gypsum will supply future Calcium and and Magnesium requirements.
I top dress again when I flip.

 

[WhiteyBulger]

Thanks Guys, much appreciated!

 

[LoveGrowingIt]

Top dressing these plants with tablespoon each of Gypsum will supply future Calcium and and Magnesium requirements.
I top dress again when I flip.

Did you mean a tablespoon each of gypsum and Epsom salt?

 

[WhiteyBulger]

I appreciate the feedback. I'm trying to determine why, my last three grows the plants always develop this symptom in late veg. Early veg everything is great so I'm thinking Gaia Green does not supply enough Mag so I may try to mix dolomite lime with my Promix next grow.

Also my well water is super hard with high levels of calcium and magnesium here in the Sierra Foothills of California. It runs thru a water softener with salt pellets in a brine tank. I'm curious if the process of using salt pellets effects my feed water in some way. I might try out a RO unit if the problem persists.

I hear people all the time saying how easy it is to grow pot. It's actually fairly technical.

 

[Oldguy71]

I’m thinking it’s nutrient lock out due to the sodium added by your water softener.

 

[GNick55]

quit ph’ing with that growing method and use tap water,..

 

[LoveGrowingIt]

I'm thinking Gaia Green does not supply enough Mag so I may try to mix dolomite lime with my Promix next grow.

I don't believe Gaia Green contains any magnesium. It's an N-P-K fertilizer. Dolomite lime, or calcium magnesium oxide (CaO•MgO), does have some, but I don't recommend using it because it raises pH. A combination of Epsom salt (magnesium sulfate, MgSO4) and gypsum (calcium sulfate, CaSO4) is a better choice. CalMag products are similar, but I prefer to use the two because I can use one or the other depending on what the plant needs. Generally, though, I add a tablespoon of each when I feed the plants, especially before beginning flowering mode.

 

[Putthataway]

I cut one of those things apart. Older unit water softeners apart and I always will remember people with those serving tastes like sea water… Big tank of salt .