PH with calMag

[TLC]

At about week 7 with 3 girls. 2 Cinerella 99, 1 Mazar.
I use AN PH Perfect. Been using it for years with no problems.
I’m using RO water 100%. My well is a bit funky.

This grow I’ve been having PH problems. A day or 2 after rez changes the PH drops to 4.5 or so.
The only change I’ve made was the CalMag. I switched to AN Sensi Cal brand since I was unable to locate my old brand.
I understand CalMag drops PH some but I’m seeing it drop and stay dropped. Adding PH up only lasts for a few hours..

Can’t say if trouble has appeared in flower phase or veg stage. I didn’t notice till last week.
The only other change was my light. Switched from 400W mh to a 400 w Cmh light

Puzzled

 

[HayStack]

What kind of nutrients are you using? Are they all AN? I use AN and they keep the ph at right around 6.0 and it's pretty consistent. I've never used RO water, but I heard it can be a little bit difficult to keep the ph right.

 

[CannaCola]

What else are you running in that Rez? Anything?

How do the roots look? How Bout smell?

Are you checking with drops or a pen?

If pen. How old are the batteries? When was the last time it's been calibrated?

Are you seeing low pH issues in the plants?


I can't see it being related to the sensi mag or CMH.

I run an 3 part. Sensimag Rhino. Some b vitamins and CMH, If i use drops to test and it buffers and holds about 6.0 for me too. Iv tried lowering it but that lasts about an hour so I gave up and haven't check it in years.

Never have had issues just ignoring it with these nutes ;-)

 

[TLC]

What kind of nutrients are you using? Are they all AN? I use AN and they keep the ph at right around 6.0 and it's pretty consistent. I've never used RO water, but I heard it can be a little bit difficult to keep the ph right.

Hi Haystack.
I’m using AN (2 part) Sensi bloom. Started using RO a few years ago when I moved into house with well water. Never had such a stubborn issue with ph.. I’m using AN Sensi Cal as well. My GH CalMag ran out so I needed to change (couldn’t find GH at the time) . Ph runs at 4.5-5 if I let it go a couple days. Also just changed to new light a month ago. Using Cmh (315 bulb) I had been using 400W HPS/Mh bulbs previous. Guy at store thinks my lights are too close. Sadly I can’t raise light any higher. There’s only 4-5 inches between light and top of closest plant.
I switched lighting to Cmh when I was 4 weeks into flower.
Many / all fan leaves are toasty brown. Buds are good sized but not seeing cloudy/amber yet. Buds seem to be drier than usual. No sticky-ness that I’m used to. (Sativa thing?)

I’ll post photo if possible.

I have another batch of seedlings to start when these finish.

I’m at week 8 now of flower so I may just flush with water now for the last week.

Tim

 

[TLC]

What else are you running in that Rez? Anything?

How do the roots look? How Bout smell?

Are you checking with drops or a pen?

If pen. How old are the batteries? When was the last time it's been calibrated?

Are you seeing low pH issues in the plants?


I can't see it being related to the sensi mag or CMH.

I run an 3 part. Sensimag Rhino. Some b vitamins and CMH, If i use drops to test and it buffers and holds about 6.0 for me too. Iv tried lowering it but that lasts about an hour so I gave up and haven't check it in years.

Never have had issues just ignoring it with these nutes ;-)

Hi Canna
Ran a little Big Bud earlier in flower, used up what I had (2 feedings) then ran out.
I change my res water and nutes once per week like clockwork.
Roots look pretty good / average to what I usually get. Checking PH with drops and pen. I used both to prove-out the pen.
I store pen in PH 7.0 liquid.
I never had PH issues with these nutes before. I’ve been using same stuff for 6 years.

 

[TLC]

Pics

 

[CannaCola]

You're definitely too close with the CMH. But like you said, not much you can do about it at this point.


As far as ph goes. I'm not sure why you're dropping. Roots look healthy. Though it's hard to see perfectly with the orange glow.


As I said, I run the same nutes as you and the 315 lamp without issue. Not sure if heat stress can cause the plant to secrete acidic byproducts from the root zone? Only difference really is I don't change my reservoir. Whatever is there stays there and just gets top ups and more nutes added. But if anything my ph drifts up to about 6 as time goes on until I add more nutes in which case it drops back down to mid 5

Are your nutes new or old? Maybe a bad batch, or its aged a bit too much and something is out of whack?

Just grasping at straws at this point. Sorry man.

 

[TLC]

No sweat.
The nutes are newer. I buy gallons and date the bottles. This is second grow from the bottles.
Guy at store said light stress will lower res PH..

My next grow I’ll be trying LST to keep the plants low.

Thanks

 

[HayStack]

Hi Haystack.
I’m using AN (2 part) Sensi bloom. Started using RO a few years ago when I moved into house with well water. Never had such a stubborn issue with ph.. I’m using AN Sensi Cal as well. My GH CalMag ran out so I needed to change (couldn’t find GH at the time) . Ph runs at 4.5-5 if I let it go a couple days. Also just changed to new light a month ago. Using Cmh (315 bulb) I had been using 400W HPS/Mh bulbs previous. Guy at store thinks my lights are too close. Sadly I can’t raise light any higher. There’s only 4-5 inches between light and top of closest plant.
I switched lighting to Cmh when I was 4 weeks into flower.
Many / all fan leaves are toasty brown. Buds are good sized but not seeing cloudy/amber yet. Buds seem to be drier than usual. No sticky-ness that I’m used to. (Sativa thing?)

I’ll post photo if possible.

I have another batch of seedlings to start when these finish.

I’m at week 8 now of flower so I may just flush with water now for the last week.

Tim

With only a week or so left to grow, there's not much you can do. Just flush with PH balanced plain water and hope for the best.
And one thing I have noticed since switching to cmh is that it does make some of the fan leaves a little crispy when you get close to harvest.
The buds do look good and you'll probably get a nice harvest.

 

[CannaCola]

i dont find mine to ever get crispy. you sure youre not too close with the light?

 

[TLC]

i dont find mine to ever get crispy. you sure youre not too close with the light?

Yes, the stretch was crazy and got out of hand.
First time growing this strain. Way too tall. Will be tying down the next batch.