Rockwool Ph problems any HELP

  • Thread starter Roxyheart420
  • Start date
  • Tagged users None
Roxyheart420

Roxyheart420

Hi Farmers, I'm hoping for some help on this. I switched from coco to rockwool on this run and it's my first rockwool grow. I'm having major ph problems in the run off which my plants are suffering from. I flush once a week. My run off ppm is around 800ppm however my ph DROPS down to 4.0 or 4.7 tonight I checked after feeding for the first time after flush last night and it was down to 3.5 WTF!!!!! I always ph my flush water to 5.9 Here's my set up. My water is ph'd at 5.9 ppm 1250 2 weeks into flower, top drip system, watering 4 times a day at 3:00min each comes to 1 liter a day. My rockwool is Hugo 8X8 Grodens. Yes, I pre-soaked. My room is 77degrees, 48-50 humidity. I have no idea whats happening. My plants are still growing tall but the leaves are yellow, curling, basically dying! I see what's happening and can't fix it. They are in nutrient deficiency because my ph in the rockwool is sooooo off. How do I dial this in?
Any help please. I don't want to lose this run. I'm under 1000wt lights. If you look close at these photos you will see dried up, curling, yellow very SAD leaves.
 
Aqua Man

Aqua Man

Staff member
Supporter
What is your source water?
What size cubes?
How often is the feeding?
What are the nutrients being used?
What is the ph down being used?

Will help get ya the info you need.
 
Roxyheart420

Roxyheart420

Thank you so much for responding. I'm using RO water. My tap water here in Cali in 280ppm. The cubes are Hugo 8X8 by Groden. My lights go on at 6pm I start watering at 7:00pm next water is 9:00, 11:00, 1:00am lights off at 6:00am My timer is set for 3:00min. each watering. Which comes to 250mls per water. I'm using Heavy 16. My line up is as follows (maybe it's something here)
I start with Silica 4ml per gal PH raises to about 9.5 then I PH it down to 6.5 before adding anything else.
Cal mg 2-3 ml per gal
Hydroguard 2 mls per
Roots 1/2 of what website recommends
Prime "
Fire "
Finish"
I use to use Sea Green but it seems to be discontinued.
PH down is by Advanced Nutrients
 
Aqua Man

Aqua Man

Staff member
Supporter
Thank you so much for responding. I'm using RO water. My tap water here in Cali in 280ppm. The cubes are Hugo 8X8 by Groden. My lights go on at 6pm I start watering at 7:00pm next water is 9:00, 11:00, 1:00am lights off at 6:00am My timer is set for 3:00min. each watering. Which comes to 250mls per water. I'm using Heavy 16. My line up is as follows (maybe it's something here)
I start with Silica 4ml per gal PH raises to about 9.5 then I PH it down to 6.5 before adding anything else.
Cal mg 2-3 ml per gal
Hydroguard 2 mls per
Roots 1/2 of what website recommends
Prime "
Fire "
Finish"
I use to use Sea Green but it seems to be discontinued.
PH down is by Advanced Nutrients
Is the ph down citric of phosphoric acid?

How much runoff are you getting per event?
 
Aqua Man

Aqua Man

Staff member
Supporter
The ph down is phoshoric acid. My run off on each watering after 250 mls is not much maybe 30mls
I would increase the runoff. Do any of those contain ammonium source nitrogen because that will lower PH. Also what the recommended dose on your cal mag? I suggest use half dose.
 
Last edited:
Roxyheart420

Roxyheart420

My Cal Mg is 2-3 ml per gal it says. My stems are red so I figured it was having a cal mg def. so I increased it. I usually back it off in flower. I don't know if anything contains ammonium source nitrate I will check. So I should increase my watering time to get more run off?
 
Roxyheart420

Roxyheart420

I will only use 6x6 cubes next time. I jumped in with both feet on the 8x8 cubes. They have been in there since they were babies. I want to dial this in so I don't have to go back to coco. So much cleaner.
 
Aqua Man

Aqua Man

Staff member
Supporter
My Cal Mg is 2-3 ml per gal it says. My stems are red so I figured it was having a cal mg def. so I increased it. I usually back it off in flower. I don't know if anything contains ammonium source nitrate I will check. So I should increase my watering time to get more run off?
Yeah I would use 1.5ml cal mag and toss in 1gram per gal of elsom salt.

The red stems is exposure to light. If you look closely it will be more prevalent on the top side and light exposed areas if that's the case.

Run your next feed until you get runoff matching the input then up the runoff each event. May benefit you to run some recharge through just to help reset the media and clear any buildup. It could take a fair bit of feed to accomplish this and I would probably do it with about 400ppm.
 
Aqua Man

Aqua Man

Staff member
Supporter
I will only use 6x6 cubes next time. I jumped in with both feet on the 8x8 cubes. They have been in there since they were babies. I want to dial this in so I don't have to go back to coco. So much cleaner.
I cant comment on the cube size as I have not grown in rockwool. But I do understand the process.
 
Ghosttrainx

Ghosttrainx

Thank you so much for responding. I'm using RO water. My tap water here in Cali in 280ppm. The cubes are Hugo 8X8 by Groden. My lights go on at 6pm I start watering at 7:00pm next water is 9:00, 11:00, 1:00am lights off at 6:00am My timer is set for 3:00min. each watering. Which comes to 250mls per water. I'm using Heavy 16. My line up is as follows (maybe it's something here)
I start with Silica 4ml per gal PH raises to about 9.5 then I PH it down to 6.5 before adding anything else.
Cal mg 2-3 ml per gal
Hydroguard 2 mls per
Roots 1/2 of what website recommends
Prime "
Fire "
Finish"
I use to use Sea Green but it seems to be discontinued.
PH down is by Advanced Nutrients
Hi I would feed at 6.30 as that's when they are fully awake if lights on at 6.00
 
Ghosttrainx

Ghosttrainx

Hi Farmers, I'm hoping for some help on this. I switched from coco to rockwool on this run and it's my first rockwool grow. I'm having major ph problems in the run off which my plants are suffering from. I flush once a week. My run off ppm is around 800ppm however my ph DROPS down to 4.0 or 4.7 tonight I checked after feeding for the first time after flush last night and it was down to 3.5 WTF!!!!! I always ph my flush water to 5.9 Here's my set up. My water is ph'd at 5.9 ppm 1250 2 weeks into flower, top drip system, watering 4 times a day at 3:00min each comes to 1 liter a day. My rockwool is Hugo 8X8 Grodens. Yes, I pre-soaked. My room is 77degrees, 48-50 humidity. I have no idea whats happening. My plants are still growing tall but the leaves are yellow, curling, basically dying! I see what's happening and can't fix it. They are in nutrient deficiency because my ph in the rockwool is sooooo off. How do I dial this in?
Any help please. I don't want to lose this run. I'm under 1000wt lights. If you look close at these photos you will see dried up, curling, yellow very SAD leaves.
So I would go 6.30 9.30 12.30 3.30 and for 5 mins so they don't dry out as much .I did niski grow wool and did 50 litre pots and only 2 feeds a day which I did turning on pump till I had run off
 
Ghosttrainx

Ghosttrainx

So I would go 6.30 9.30 12.30 3.30 and for 5 mins so they don't dry out as much .I did niski grow wool and did 50 litre pots and only 2 feeds a day which I did turning on pump till I had run off
Don't worry about ph that comes out u need to check on in the medium if in flower 2.0 EC is the highest to go start bloom at 5.8 ph first few weeks then 6.0 and last 2 weeks 6.3 as it will rise over couple days ...If your ph in brain is dropping your adding your nutes in wrong order and most nutes have stabilizers and will sit at the range it works best at check water temp is between 19 to 24 c aswell👻🚂🤜🤛
 
DreamwalkerJ

DreamwalkerJ

I would increase the runoff. Do any of those contain ammonium source nitrogen because that will lower PH. Also what the recommended dose on your cal mag? I suggest use half dose.
I would also recommend that adjusting your pH is the LAST thing you should do. Most nutrients have buffers in them to help maintain a proper pH. So when you add silica pH shoots up and then pH down so now its trying to stabilize, then you add your nutes which try to stabilize and buffer, then you adjust pH again and THEN it finally gets to sit and stabilitze. IMO there are too many changes happening. Add you silica, then calmag, then your nutes/additives, let it sit for 30 minutes and THEN adjust pH
 
Aqua Man

Aqua Man

Staff member
Supporter
I would also recommend that adjusting your pH is the LAST thing you should do. Most nutrients have buffers in them to help maintain a proper pH. So when you add silica pH shoots up and then pH down so now its trying to stabilize, then you add your nutes which try to stabilize and buffer, then you adjust pH again and THEN it finally gets to sit and stabilitze. IMO there are too many changes happening. Add you silica, then calmag, then your nutes/additives, let it sit for 30 minutes and THEN adjust pH
Definitely... and if silicate add first mix 20 min then add the rest in order and always ph down at the end 👍
 
Top Bottom