Auto Flower Advice

[Shumroom]

Thanks HRnT 

 

 

 

Atb

 

 

 

 

[Void22nds]

So does this mean its a magnesium deficiency ? because I do have Calmag on hand

[Shumroom]

If you were to add CalMag, 

you wouldn't be fixing the ratio. 

 

It's important that they are at roughly the right ratio(3:1),

so please don't go adding more Calcium and Nitrogen(yes CalMag contains N as well). 

 

Give @Oldbear a chance to respond, 

he's around most days 

 

Atb 

 

 

 

[Void22nds]

Oh okay, thanks for clearing that up.

 

Will do 

[Herbal Kint]

Try photos next round,they are more consistent if you pick decent strain.

[RUFUS HOUND]

It could be a magnesium def but f it was, why did it only affect 1 plant and not both? Id be leaning toward overwatering but I cant tell as your photo is tiny - post a bigger photo of a few of the worst areas (right way up)

 

Hopefully @Oldbear will show us thicko's how to work it out - knowledge is power and all that.

 

 

 

[Oldbear]

Apologies for the late reply, I'm having real issues using the site lately. 

 

Can someone post the ppm of the cal and mag and I'll do the calcs straight away 

 

[Shumroom]

Cheers @Oldbear 

 

Milligrams per litre/ppm

Mg 6.26

Ca 74.9

 

Atb 

 

 

 

[Void22nds]

@RUFUS HOUND I removed the plants from the grow tent so that they would be more visible. Even though both plants received the same lighting and feeding, the Blue dream buds are much denser. 

 

Blue Dream

 

DSD

 

[RUFUS HOUND]

have a look at this, lots of good info https://www.cannabisbusinesstimes.com/article/magnesium-part-of-a-balanced-cannabis-diet/

 

As it stands your waters ca:mg ratio is 12:1, so you will need extra mg adding to bring it to 3:1

going by the info in the link 

The fix for a Mg deficiency is easy. Epsom salts (magnesium sulfate) can be applied at the rate of 2 pounds per 100 gallons of water (2.4 kg/1000L). Apply this as a 5 percent to 10 percent flow-through leaching irrigation. This will stop the progression of symptoms, but will not reverse any interveinal leaf chlorosis or necrotic spotting. For areas that lack sufficient Mg in their irrigation water, and Mg is not part of the regular fertilization program (i.e., 20-10-20 does not contain Mg), monthly applications of Epsom salts at the rate of 1 pound per 100 gallons of water (1.2 kg/1000L) is the common production practice to green up plants and avoid deficiencies.

so  thats 2.4g per litre to treat a def and 1.2g/L once a month to keep it from occurring but these are rough estimates not considering your water results.

Also interesting is that over 100ppm mg can reduce yield and approx 75ppm seems to be the sweet spot.

 

@Oldbear will be along with the precise amount of mono mg  you will need to bring your ratio to 3:1

 

A quick way to give them a magnesium boost would be to make an epsom salt foliar spray and use at lights out.

[Oldbear]

18 hours ago, Shumroom said:

Cheers @Oldbear 

 

Milligrams per litre/ppm

Mg 6.26

Ca 74.9

 

Atb 

 

 

 

 

 

If you add 0.43ml per litre of mono magnesium you'll be sweet. You need 18mg more mg than you have 

 

Hope this helps 

[RUFUS HOUND]

25 minutes ago, Oldbear said:

 

 

If you add 0.43ml per litre of mono magnesium you'll be sweet. You need 18mg more mg than you have 

 

Hope this helps 

Can you show how you got to this figure to see if I can get my head round it

[Oldbear]

2 hours ago, RUFUS HOUND said:

Can you show how you got to this figure to see if I can get my head round it

I'll try 

 

I divided his cal by 3, subtract the existing mg from that number and divide by 43.3 (mg in mono is 4.3% its 7% with O ) this gives the ml per L to add for the correct ratio. 

 

 

 

[RUFUS HOUND]

cheers mate @Oldbear much appreciated

[Void22nds]

@RUFUS HOUND
@Oldbear

Thank you guys I appreciate it a lot