Brown spots - calcium deficiency?

Busternutt

Well-Known Member
Hi guys, I'm trying my hand at a grow again for the first time in a few years. Strain is Amnesia Lemon feminized and I'm using an ebb and flow system with a 12 litre reservoir and perlite as the grow medium. When the seed struck, I put it in a humidifier thing for a week then put it in my grow cupboard in the ebb and flow system on the 4th of August. Until yesterday (22nd August) I was only using a CFL on 24 hours, yesterday I swapped to LED with VEG selected and changed to 18/6. I am using Cultiplex Extra-Nutrex GROW food at minimum strength of 6ml into 12l. I was using it a little stronger but the PPM was very high and the leaves went quite pale with darker green veins. At the current feed strength, the colour came back to the leaves and I can keep the PPM between 100 - 200 and the pH at 5.9, although the pH slowly creeps up over a few days. I'm also using De-Fuse nutrient conditioner at minimum strength (recommended because I'm on tank water). The feed system is set to come on for 15 minutes every 4 hours.

I noticed a couple of little spots a few days ago but thought it might have been light burn as I'd originally had the CFL quite close but with the CFL gone, there are a few more spots and the older ones are bigger. I've read through the FAQs and I thinking it looks a calcium deficiency. Can anyone confirm or correct me please? IMG_3584.JPG IMG_3582.JPG
 

Cx2H

Well-Known Member
Rust spots, yeap you are correct in the need for calcium.
You using ro water?

How long into the light cycle were these pix taken this day? Droop
 

Hempire828

Well-Known Member
I had same issue same look.. calcium def.. I foliage feed with calcium solution at 7-7.2 I think my medium was to acidic.. a few tap waterings...of 7.2...then balanced ph toward 6.5 & things got back to normal... I joe use a mixture of 2:1 cal/ mag.. these seem hungry for it..
 

Busternutt

Well-Known Member
Yes, rust spots is a perfect description. I took these pics today, changed the light cycle yesterday so as of now, she's in darkness for the second time. I'm not using RO water, just my tank water. Before I add anything to my tank water, when I check it nothing reads on the ppm meter and the pH is around 7.4 so I've been adding nutrients at the amounts I said above, then correcting the pH to 5.9

I'm assuming a calcium solution would be available from a nursery or hardware shop?

Thanks for your help guys
 

hotrodharley

Well-Known Member
Yes, rust spots is a perfect description. I took these pics today, changed the light cycle yesterday so as of now, she's in darkness for the second time. I'm not using RO water, just my tank water. Before I add anything to my tank water, when I check it nothing reads on the ppm meter and the pH is around 7.4 so I've been adding nutrients at the amounts I said above, then correcting the pH to 5.9

I'm assuming a calcium solution would be available from a nursery or hardware shop?

Thanks for your help guys
Turn both switches on your light on.
 

hotrodharley

Well-Known Member
Yes, rust spots is a perfect description. I took these pics today, changed the light cycle yesterday so as of now, she's in darkness for the second time. I'm not using RO water, just my tank water. Before I add anything to my tank water, when I check it nothing reads on the ppm meter and the pH is around 7.4 so I've been adding nutrients at the amounts I said above, then correcting the pH to 5.9

I'm assuming a calcium solution would be available from a nursery or hardware shop?

Thanks for your help guys
How can your meter not register EC/TDS in “tank water”? Something doesn’t sound right.
 

MoodyShoes

Well-Known Member
Get some calmag. Calcium and magnesium. It's very difficult to differentiate between the two deficiencies.
 

Busternutt

Well-Known Member
I've been reading online and think I may have had the TDS too low and not allowing the plant to take up calcium. I still had it at "seedling" amounts whereas I guess it wants more. TDS is now 300 - 400 ppm and I adjusted the pH to 6.2. I'll also get some Calmag on Monday

I run my tank water through a filter so I guess it takes everything out
 
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