Brown Spots with Yellow Halo

[jdm61]

looks like fairy poop.......

 

[Phrygian]

Don't worry about the PH of the run-off. The plant will exude substances that change the PH around the roots biome. Just be mindful of the PH of the fertigation.

I am looking at this again and this might be an actual case of a Cal-Mag deficiency? What is your water source and starting PPM?

Will do, thanks! Adjust mix to 6.3-6.4 ph?

City tap water (see attached water summary)
PPM: 76 (.5 ppm) (.2 EC)

 

[Phrygian]

Water from the Ottawa River is very soft and has a natural "tea" colour due to the highly forested watershed and the breakdown of leaves, bark, and trees. A “multi-barrier” approach is used, involving a series of physical and chemical treatment steps that remove undesirable substances such as colour, suspended particles, algae, bacteria, and viruses from the water in about eight hours.

 

[Mañ'O'Green]

Will do, thanks! Adjust mix to 6.3-6.4 ph?

City tap water (see attached water summary)
PPM: 76 (.5 ppm) (.2 EC)

That is the most complete water report I have seen. You should treat for chloramines. 1.6 PPM so 25 mg ascorbic acid per gallon.

You have very little in the way of calcium in your water, ~20 PPM so I think you need to add some to your fertigation. I would add 75 - 100 PPM to start and see if the symptoms stop progression.

 

[Phrygian]

That is the most complete water report I have seen. You should treat for chloramines. 1.6 PPM so 25 mg ascorbic acid per gallon.

You have very little in the way of calcium in your water, ~20 PPM so I think you need to add some to your fertigation. I would add 75 - 100 PPM to start and see if the symptoms stop progression.

Oh wow! Awesome, thanks for the info!

Any powdered ascorbic acid?

What would be the mixing order?

1. Ascorbic acid
2. Cal-Mag
3. Sensi A+B

 

[Mañ'O'Green]

Oh wow! Awesome, thanks for the info!

Any powdered ascorbic acid?

What would be the mixing order?

1. Ascorbic acid
2. Cal-Mag
3. Sensi A+B

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.





and then the Sensi A&B.

 

[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.

Awesome, thanks for all your help!

I think the PH drops quite significantly by the time it gets to my tap in my area. PH strips show it as 6 PH. I'll have my new PH pen by tomorrow though, so I'll have a more accurate reading then. Ascorbic acid will arrive tomorrow as well. I'm going to hold off on phosphoric and nitric - too complicated for me..lol

 

[Mañ'O'Green]

Awesome, thanks for all your help!

I think the PH drops quite significantly by the time it gets to my tap in my area. PH strips show it as 6 PH. I'll have my new PH pen by tomorrow though, so I'll have a more accurate reading then. Ascorbic acid will arrive tomorrow as well. I'm going to hold off on phosphoric and nitric - too complicated for me..lol

No it is not complicated you just add a little of this and a little of that. It is a mute point if the water coming out if the tap is 6 PH.

 

[Phrygian]

Wow, so I'm throwing those PH strips out. Just took a reading of my tap water with my new PH pen (I even calibrated it), and my reading was 9.0 PH!!

However, I did a test mix of 1 L water and 1ml each of Sensi Bloom A+B, which brought the PH down to 6.3

 

[Flux]

Wow, so I'm throwing those PH strips out. Just took a reading of my tap water with my new PH pen (I even calibrated it), and my reading was 9.0 PH!!

However, I did a test mix of 1 L water and 1ml each of Sensi Bloom A+B, which brought the PH down to 6.3

I tried the ph strips and narrowed down my tap water to about 6 comparing the strip to the back of the bottle then used my perfectly calibrated pen and got 8.3 !!!!!!! Those strips are a complete crapshoot!