Calcium def?

[Phreakoftheweek]

Problem: Some brown spots and mild yellowing on leaves near top of plant

Medium/grow method: Botanicare coco with 25% perlite and 10% rice hulls

Feed: and supplements used:Modified Lucas formula of 6ml Micro and 9ml of bloom per gallon, General Hydro brand. Also use 3ml of Calimagic per gallon and 2 ml of Hydroguard. I have hand watered the 5 gallon smart pots with with above solution once a day once roots were established, ph to 5.8 and solution diluted to 750ppm. Watered early until just a bit of runoff but last few days have watered until 20% runoff

water source: Glacier self serve station, its supposed to go thru RO process and various other filters. PPMs are between 0-6, pH runs a touch high at 8.1.

Strain/age:Mephisto AvT, almost 5 weeks

light used: Tasty T4 COB led in a 30 x 48 cabinet 6 feet tall. Light is 16 inches above the canopy

Climate: Temps have been 75-81 its entire life, just lowered rH the last couple of days from 55% to 47%

Additional info: I believe I let the coco get too dry one day last week and I noticed the spots and yellowing appear a day or so later. On Sunday I flushed with 12 gallons of my normal feed/water solution. Plant looks healthy except for the leaves with spots and yellowing. Not on all leaves just several near the top of the plant. There is a Mephisto Sour Orange Livers beside it with no problems.

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[MedGrower]

Hey bro! Looks like combination of Ca and Mg defiency to me. Intense light, pH 5.8 with RO water supports that too.

Make sure you are making about 0.4 EC / 200ppm impact adding CalMag to your RO water and up the pH to 6.2 for now for better Ca and Mg absorbtion. I keep my pH always around 6.2 in hydro, and I see you have coco, so that is soilless medium so same rules applies.

Hope this helps!

 

[Phreakoftheweek]

Hey bro! Looks like combination of Ca and Mg defiency to me. Intense light, pH 5.8 with RO water supports that too.

Make sure you are making about 0.4 EC / 200ppm impact adding CalMag to your RO water and up the pH to 6.2 for now for better Ca and Mg absorbtion. I keep my pH always around 6.2 in hydro, and I see you have coco, so that is soilless medium so same rules applies.

Hope this helps!

Thanks for the reply!! I have upped my ph to 6.3 since I flushed on Sunday. I know for sure that ppm of cal mag is less than 200 so I will up it a bit to see if that helps. Lots of experience growing outdoors but this is my first indoor run. Thanks again!!

 

[MedGrower]

Thanks for the reply!! I have upped my ph to 6.3 since I flushed on Sunday. I know for sure that ppm of cal mag is less than 200 so I will up it a bit to see if that helps. Lots of experience growing outdoors but this is my first indoor run. Thanks again!!

Glad I could help bro. Normally I add something like 0.3 EC / 150ppm to my feed but since you have RO it may be best to give little extra. Once you get Ca -defiency symptoms they might keep popping up through the grow still. Cant tell you how many times it has happened to me but you can keep it at bay and it will thankfully just look ugly and nothing else.

If you are having any Optic Foliar available at your location, that may really help you to remedy the situation effectively!