Brown Spots with Yellow Halo

[MesaBoogie]

I had a similar situation with my test strips when I first start growing. That's why I recommended even a cheap PH pen over strips. I have a couple dropper test kits too. One is reasonable close and the other is garbage. I like having the backup incase I get a funky reading with my pen and I want to make sure there is no issue with the pen.

 

[Phrygian]

You are looking for ascorbic acid - vitamin C. The store brand is usually the cheapest without other stuff added in.

Yes I would mix the ascorbic acid the day before and aerate (or stir pump) overnight.

Then mix in the Cal-Mag.

You need to bring down that 9.48 PH to at least 7. The ascorbic acid and aeration may bring it down some and it might not be that high coming out of your tap. It might work best if you could use some of phosphoric acid and some nitric acid so you don't raise the N or P too high while lowering the PH. Add a tiny amount of nitric acid and wait 30 minutes to test the PH it is slow acting but has a large effect. Drop your PH to ~8.5 with this then use the phosphoric acid to get to 7 I have screwed up more than one reservoir of nutrients by overdoing the nitric acid.

This is the brand I use.



View attachment 1286035View attachment 1286037

and then the Sensi A&B.

Quick question - If I'm only watering and not feeding, do I still add cal-mag?

 

[Bill.de.Cat]

I had a similar situation with my test strips when I first start growing. That's why I recommended even a cheap PH pen over strips. I have a couple dropper test kits too. One is reasonable close and the other is garbage. I like having the backup incase I get a funky reading with my pen and I want to make sure there is no issue with the pen.

Seems it's a good idea to have multiple testing sources to test against as you never know when one is gonna start giving bad readings..

 

[Mañ'O'Green]

Quick question - If I'm only watering and not feeding, do I still add cal-mag?

No.

Read this:

Tutorial - A word on Nutrients

The proper use of “salt” based fertilizer to grow Auto Flowering Cannabis. Salts: Natural and man made any chemical compound formed from the reaction of an acid with a base, with all or part of the hydrogen of the acid replaced by a metal or other cation. Learning how to use salt based...

www.autoflower.org

 

[Phrygian]

No.

Read this:

Tutorial - A word on Nutrients

The proper use of “salt” based fertilizer to grow Auto Flowering Cannabis. Salts: Natural and man made any chemical compound formed from the reaction of an acid with a base, with all or part of the hydrogen of the acid replaced by a metal or other cation. Learning how to use salt based...

www.autoflower.org

"I often encounter new growers adding Cal-Mag to a pot by itself. This is the definition of out of balance since all of the other elements are absent."

Merci buckets