Need help identifying this deficiency!

[Cowabunga1998]

coco coir medium,
RO water Athena cal mag
Athena blended nutrients
They are definitely growing fast but this deficiency is showing on all 3 different strains I have going right now and can’t figure out to save my life

 

[Nectarivorous]

coco coir medium,
RO water Athena cal mag
Athena blended nutrients
They are definitely growing fast but this deficiency is showing on all 3 different strains I have going right now and can’t figure out to save my life

Can you provide some info on your lighting? How much Calmag are you using?

 

[Nectarivorous]

Are you buffering your water for pH? What is the pH in and out?

 

[Cowabunga1998]

Are you buffering your water for pH? What is the pH in and out?

≈4mg camg per gallon
Spider farmer at 4000 at 50% approx 18” away from canopy
ph is around 5.7-5.9 goin in
I feel stupid for saying this but I haven’t buffered my water nor checked ph runoff can you elaborate?

 

[Nectarivorous]

≈4mg camg per gallon
Spider farmer at 4000 at 50% approx 18” away from canopy
ph is around 5.7-5.9 goin in
I feel stupid for saying this but I haven’t buffered my water nor checked ph runoff can you elaborate?

So I always preface by saying I'm a first time grower so get confirmation from the old firm. But I would suggest that is way too much light for these little guys. At this stage I had similar power LEDs 30 inches away at closer to 30%. They should be getting somewhere around 300-350 PPFD. The only way to know is to test how's much light they are actually getting. If you have a recent iPhone download Photone and check how much they're getting but I'd be moving them back to 30". Too much light will drive the plant very hard photosynthetically and push it into deficiency.

Could also be a pH issue. Calcium and magnesium are very sensitive to changes in pH and can start to not be absorbed once you leave the ideal zone for seedlings in Coco of 5.8-6.0. If using RO you need to buffer for pH or pH in the medium can start to swing wildly, as high as 10 even which is way off.

I start with RO, add 3 ml/litre of Silica (I'm in a metric country sorry haha). Allow that to dissolve for at least half hour. Test pH, will be around 10. Use pH down to get down to 6-6.3. Then add Calmag at 2ml/litre. You could probably bring those down a bit and keep the ratios the same but these are the amounts that work for me. This will buffer your pH and stabilise it in the medium. The silica will increase the strength of your plant and protect against disease and give you massive thick trunks and branches and therefore amazing water supply. Hopefully this helps let me know if any of that didn't make sense I'm a bit blazed hehe

 

[mysticepipedon]

What you're seeing is signs of magnesium (Mg) deficiency. HOWEVER it doesn't always mean there isn't enough Mg, it could be a pH issue or another nutrient interfering with Mg uptake.

 

[Cowabunga1998]

What you're seeing is signs of magnesium (Mg) deficiency. HOWEVER it doesn't always mean there isn't enough Mg, it could be a pH issue or another nutrient interfering with Mg uptake.

Okay do you have any ideas on some things I should always check ?

 

[StoneyMahoney]

Early to Intermediate stage of Cal Mag deficiency...

 

[mysticepipedon]

Okay do you have any ideas on some things I should always check ?

Check your pH, maybe add a little Cal/Mag next time you water

 

[Nectarivorous]

Check your pH, maybe add a little Cal/Mag next time you water


Still say need to sort the light out too. If you're trying to add Calmag but not correcting the over delivery of photons that is driving the demand you're chasing your tail to some extent.

 

[mysticepipedon]

Check your pH, maybe add a little Cal/Mag next time you water


Still say need to sort the light out too. If you're trying to add Calmag but not correcting the over delivery of photons that is driving the demand you're chasing your tail to some extent.

Because of that extra demand, I've been looking for soil additives with Mg in them, aside from dolomite. I'm giving some added alfalfa meal a try in my current grow.

 

[Cowabunga1998]

Are you buffering your water for pH? What is the pH in and out?

How do you buffer coco ???

 

[Nectarivorous]

How do you buffer coco ???

I start with RO, add 3 ml/litre of Silica (I'm in a metric country sorry haha). Allow that to dissolve for at least half hour. Test pH, will be around 10. Use pH down to get down to 6-6.3. Then add Calmag at 2ml/litre. You could probably bring those down a bit and keep the ratios the same but these are the amounts that work for me. This will buffer your pH and stabilise it in the medium. The silica will increase the strength of your plant and protect against disease and give you massive thick trunks and branches and therefore amazing water supply.