Promix ph

Dan can grow

Well-Known Member
I'm currently growing several strains in promix. I use general hydroponics nutrients and always ph to 5.9 with ppm around 550 for veg.'s Some of my plants are great but two in particular look bad. I'm talking brown necrosis and really purple stems. At first I thought a cal mag issue so I bumped up my camg and Epsom salts. Getting worse. So my instinct took over and did a test with a different clone. I ran straight rain water and the ph was 7. That test plant had lost most purple and necrosis. So my question I guess would be is my ph at 5.9 a bad level in promix being it is peat based and more acidic already? Or was it my ppms. I'll test runoff tomorrow
 

Dan can grow

Well-Known Member
I do own a ppm meter and use it every time I prepare water. My tap comes out at 70 ppm. I usually add 1ml micro 2 ml bloom and 3ml gro per gallon of water With ph down to 5.9 my ppms are right around 550.
 

Dan can grow

Well-Known Member
I've been researching this a lot. So I ran one clone. I used 7 ph rain water and it is looking better. I will increase ph to 6.3 for veg. What should I run for flower?
 

dandyrandy

Well-Known Member
I use promix as well. I pH around 6.1 to 6.2. Peters fert running and EC of 1.2 or so. Then add 3 ml calmag at this point. Some like more than others. I have a big leaf indica which needs a bunch.
 

Kingrow1

Well-Known Member
I run promix and my ferts are very acidic, i dont ph anything and have zero issues. Lime in promix should be all the ph you need.

Strange how everyone ph's everything for lime based media.....
 

Dan can grow

Well-Known Member
Ok so ya own a ppm meter, good. Now how big is that plant? I run three footers at 500 ppms. Do you have any pictures of the damage?
I also veg to about 18". I start feed at around 200 ppm and increase a little every other watering until it's at about 550. During flower I'll run about 950 ppm
 

Dan can grow

Well-Known Member
I thought so a bit also so I stopped all feeds and just watering with 6.3 ph water. Never saw leaf burn leave necrotic spots and purplish like this. That's why I wanted to know if 5.8 ph was too acidic. These plants did purple last run too but not this extreme
 

Dan can grow

Well-Known Member
I should also note that I'm using a led light. 300 watts, full spectrum. My small clone box I use CFL and no purple there. Is that light too intense for my little 2x2 area?
 
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