Why is Low PH in Veg Fine vs. Flower Stage? Continous Problem...

G

Grooven420

New Member
Hey Folks,
After my a couple semi good size grows in Sunshine #4 soil I started having the same problems that HarryRed described
sometime back in that I noticed leaves would turn yellow 2-3 weeks into Flower. This is a clear sign of Mg deficiency due to low PH. I had
tried adding Epsom salts, etc to counteract the problem with no real improvements because the PH was still too low.

So I put the cash on the counter for a good OAKTON PH meter. Now I am seeing some rather shocking things. First I noticed that
even though the plants in the Veg room look great I was measuring anywhere from 5.4-5.9 PH. I was shocked because the girls still
looked great even though the low PH. After seeing this I went out and got crushed dolomite lime and mixed it in with the plants that are already
in their homes with very little move on the PH scale. Secondly, ones that I have transplanted into new homes with
Sunshine #4 right out of the bag and several Tbl's of Dolomite lime mix'd in with the soil I am still measuring 5.8-5.9? I am almost at a crossroads as to
whether to change the soil I am using or even go soilless but soilless certainly seems to have its own challenges. I am trying to get the PH into the
normal range for any plants in the Veg room before I move them into the 12/12 room to avoid problems that I have had in the past but it is seemingly
more difficult than I expected to get them into a stable 6.5-6.8 range. I am also PH'ing the H20 & Nutes to 6.8
to try and help out but still getting readings in the mid to high 5's?

Any suggestions?

Some questions...

1) Has anyone tried adding Natural UP directly to the soil to try and
improve things? If you do does it stabilize the soil PH or is it just
a temp fix?
2) I am rather baffled as to why Girls do so well in the Veg room with
low PH's but as they get flipped to 12/12 they freak out after a
couple of weeks?


Confused and Frustrated...

Any help would be GREATLY APPRECIATED...Thanks already to HarryRed!!

L8R,
Grooven420
 
I have a question, do u have Ph regulating solution?

I have the liquid PH testing stuff, and depending on the numbers, i have the Ph solution to increase or decrease the PH.

Maybe when u water your soil, u can increase the PH of the H2O and perhaps that'll help adjust your soil.


Then again, it could be a bad soil compound mix... =x
 
Grooven420 said:
Hey Folks,
After my a couple semi good size grows in Sunshine #4 soil I started having the same problems that HarryRed described
sometime back in that I noticed leaves would turn yellow 2-3 weeks into Flower. This is a clear sign of Mg deficiency due to low PH. I had
tried adding Epsom salts, etc to counteract the problem with no real improvements because the PH was still too low.

So I put the cash on the counter for a good OAKTON PH meter. Now I am seeing some rather shocking things. First I noticed that
even though the plants in the Veg room look great I was measuring anywhere from 5.4-5.9 PH. I was shocked because the girls still
looked great even though the low PH. After seeing this I went out and got crushed dolomite lime and mixed it in with the plants that are already
in their homes with very little move on the PH scale. Secondly, ones that I have transplanted into new homes with
Sunshine #4 right out of the bag and several Tbl's of Dolomite lime mix'd in with the soil I am still measuring 5.8-5.9? I am almost at a crossroads as to
whether to change the soil I am using or even go soilless but soilless certainly seems to have its own challenges. I am trying to get the PH into the
normal range for any plants in the Veg room before I move them into the 12/12 room to avoid problems that I have had in the past but it is seemingly
more difficult than I expected to get them into a stable 6.5-6.8 range. I am also PH'ing the H20 & Nutes to 6.8
to try and help out but still getting readings in the mid to high 5's?

Any suggestions?

Some questions...

1) Has anyone tried adding Natural UP directly to the soil to try and
improve things? If you do does it stabilize the soil PH or is it just
a temp fix?
2) I am rather baffled as to why Girls do so well in the Veg room with
low PH's but as they get flipped to 12/12 they freak out after a
couple of weeks?


Confused and Frustrated...

Any help would be GREATLY APPRECIATED...Thanks already to HarryRed!!

L8R,
Grooven420
Click to expand...

Hey Grooven :welcome:..
PH fluctuations are sorta normal. Normal in the sense that, you could be doing everything right and still dealing with either low ph or high ph..
there are a few places like htgsupply that sell ph up and ph down fluid.
You ph your soil.. its too high, you add some ph down..
if its too low you had some ph up.. this may help for the time being while you figure out whats causing the fluctuation or til you switch mediums :)

Smokeyjoe said:
I don't have an answer for you but I am running into the same problem with FF OF soil. Gonna watch for replys. Good luck with yours!
Click to expand...
Dudee your sooo right.. i phed the soil(w/o anything in it) and it was 6.2, but my FF light warrior was 5.7 i was like errrg!

Lil Neutrino said:
Grooven, you reminded me of a question I had a little while back...

How do you go about mixing the lime in to the soil that your plants are already in without messing up the roots??? Thanks!
Click to expand...

hey lil N.. you just sprinkle it on top before your next watering and water it in(without over watering :surf:)

good luck with your grow grooven:peace:
hope you have a great harvest!!!:yummy:
 
Hey Everyone,
Thanks for replying...seems like I am certainly not the only person having trouble regulating the PH in soil. I am still rather confused as to why the girls look great in Veg in low PH but after 2-3 weeks after they get flipped into 12/12 they show major signs of Mg deficiency because of the low PH?

Fattis-Rattis -> I have both Natural UP(Earth Juice Crystals) and PH Down which I do use to PH my H20 + Nutes as after my water has sat 24hrs its PH goes up into the low 7's.

So are you saying to add the Natural UP directly to the soil? I have in other posts not to add anything directly to soil to adjust PH except for Pulverized Dolomitic Lime...?

McBudz did mention that he adds 1-2 cups per Cu Ft whereas other places I have read to add 1-2 Tablespoons of D. Lime...I think I will try to keep adding more dolomitic lime to the girls soil in the veg room till it gets to normal levels and then flip them.

Lil Neutrino -> I actually rough up the first couple of inches of soil to try and get the D. Lime to absorb deeper into the soil quicker. I have found that it globs up if you just leave it on top forming balls which are difficult for water to break up if you don't...

Just seems like there should be a proven/easy way to ensure you have a stabilized PH in soil or that someone makes a soil that they have tested that does not fluctuate so rapidly over time...sounds like if someone did they would have a lot of customers lined up ready to buy.

L8R,
Grooven420
 
Most soil mixes are acidic to start out which is why the DL is recommended as an amendment. However, with most forms of DL, you must mix it in with the soil prior to planting. This assures that it gets throughout the medium to counteract the acidity. DL isn't very soluble as you have noticed... even with very finely ground powder it tends to clump. Thus, top feeding after the mix isn't an effective option. Doubtful you will be able to get it deep into the pots, especially if you are using a chunkier version.

If you want to have a more immediate & effective method of raising the pH without retilling it, then you can try Hydrated Lime, again finely ground powder version. Be very cautious though as the HL doesn't cap out around ph7 as the DL, it will go up & up & up with very, very, very little added. No bs... a tblspn per 5gal will toss you up over 10.0pH. However, it is quick acting & highly soluble (get down into the soil). You will likely need to feed multiple times though & really watch your run-off pH.

On this note, how did you measure the pH of your soil? Did you actually pull some soil & soak it in distilled water to measure properly? Are you measuring the run-off instead? The reason I ask is measuring soil pH accurately is very, very difficult, especially if using organic based soil nutes. If you see your plants so happy, perhaps your pH issue isn't a problem at all...? Progressive yellowing from the bottom up isn't a tell tale sign of Mg def but rather N. Are they spotting with a rust color dot? This is usually your key indicator of Mg. Pics would really help. Regardless, if Mg is the issue, foliar spray your epsom salts to address. Foliar applications will be immediately available regardless of your soil pH.

Best regards.
 
BTW, your micro's like Mg are usually more available at lower pH's whereas your macros become deficient here. Vice versa when pH is too high. Mg tends to be available across the spectrum unless you are around 5.0 & under. Best.
 
gio77 said:
Be very cautious though as the HL doesn't cap out around ph7 as the DL, it will go up & up & up with very, very, very little added. No bs... a tblspn per 5gal will toss you up over 10.0pH. However, it is quick acting & highly soluble (get down into the soil). You will likely need to feed multiple times though & really watch your run-off pH.
Click to expand...

Yeah, I can personally attest to this. I added maybe 2 tablespoons to about 8 quarts (look for my post about it, I forget the title and subforum) and when I checked the pH of the runoff water (distilled) it was around 9 using FFOF (supposed to be at most 6.8)! Best to add too little and work your way up than to add too much and pH shock the heck out of the plants. I got it mixed up with dolomite lime and thought it would buffer the soil at 7...boy was I ever wrong!
 
Hi Gio77,
First Thanks a TON for the response as you really got me thinking again as to what the real problem is...I will try to get a photo posted here tonite, a couple of notes as to how I am measuring the PH and a Written description of the problem...

1) I am actually just measuring the runoff with nothing but H20 when I am measuring the PH and the H20 I have PH'd to 6.7/6.8.

2) Description of Problem -> A general Yellowing/Whitening of the leaves
starting from the base up and it affects the fan leaves first then followed
by the leaves surrounding the bud site. In the 3 that are worst I am not
seeing any rust just yellowing/whitening followed by the leaves dying.

That is GOOD to know that the girls can still absorb Mg at the lower PH's...

So if it is a N def I am assuming that at the lower PH's they can't abosrb N?
Do you know at what PH they can start absorbing N again?

In looking at the 'Plant Abuse Chart' on the 'How to Grow Marijuana' section I think you have nailed it!! My leaves are not curling and it is a totally even yellowing...I also looked up and found several N substances and their acidity vs.
base in which if I have a low ph now I would want to add the base variety which
appears to be one of these 3...


N Source Potential acidity Potential Base
Calcium nitrate----------------0-----------400

Potassium nitrate--------------0-----------520

Sodium nitrate-----------------0-----------580

I am using all Fox Farm products right now I will check to see which one has a
High N, I am assuing the Grow Big...does it make sense to give a healthy dose of that if it has a high N?

Thanks a TON!!

Later,
Grooven420
 
Hey Gio77/Anyone,

N Def-> If treated how long would you expect to see improvements in the girls after they have been given a decent dose of N?

Thanks a TON!!
Grooven420
 
Grooven420 said:
1) I am actually just measuring the runoff with nothing but H20 when I am measuring the PH and the H20 I have PH'd to 6.7/6.8.
Click to expand...

I didn't see you say if you were using distilled water or not...but that pH looks fine.

So if it is a N def I am assuming that at the lower PH's they can't abosrb N?
Do you know at what PH they can start absorbing N again?
Click to expand...

This is from this sticky at the top of this forum (TONS of information, hard to soak up until you've read it four or five times ha!)

PH levels for Nitrogen:

Soil levels
Nitrogen gets locked out of soil growing at ph levels of 4.0- 5.5.
Nitrogen is absorbed best in soil at a ph level of 6.0-8.0. ( wouldn't recommend having a ph of over 7.0 in soil) best range to have nitrogen is a ph of 6-7. Anything out of that range will contribute to a nitrogen def.
Click to expand...


And yeah, the Grow Big should have the high N as it is meant for the veg state and the Big Bloom and the other one are more for flowering.
 
Hi groovin, intended to help, so hope I'm not making the matters worse! It is so tough to give accurate & applicable advice without actually being in/near the situation, so...

I'm a big believer that pH is the source of most nute problems, in one way or another. The simplest answer is always to up the nute levels with a def, but often that doesn't address the underlying issues. The low pH in the medium might be the problem but you should also see other nutrient problems arising, e.g., K and/or P, where K is the biggest one I notice (even over N). So, perhaps it is as simple as uping the nute levels...?

The most immediate means to address almost any nute deficiency (not lockout mind you) is to foliar spray with a balance nutrient mix. I have had best success when this mix is no higher than 350-400ppm's & it is advisable to raise the lights a little for the hour or two after you spray them. Lower temps also help during foliar sprays. Don't do it anywhere near the end of the day as you will create a rather large spike in humidity & you don't want any type of fungi to take hold as an unintended side effect. You should see an immediate response from the plant within a day, if not within the same 12-hour period. The next day for sure.

I just use my base nutes (they're hydro though) @ pH 6-7 @ 350-400ppm's. You can specialty sprays that attempt to address stress which tends to just have the micros fortified, but pretty much any balanced spray will work. If you do this multiple days, would recommend one day off between sprays & go lower say 300ppm's. Hope this helps! Best.
 
Hey Goi/Lil Neutrino,
I believe I am seeing some recovery...my PH runoff with 6.8HP'd Nutes & H20 is up around 6.5-6.9 in which I gave them a good does of Grow Big & Cha Ching both FFarms product but saw they had a higher percentage of N. Will let you know how things look here in a few days...

Thanks a TON Again!!

L8R,
Grooven420
 
gio77 said:
Most soil mixes are acidic to start out which is why the DL is recommended as an amendment. However, with most forms of DL, you must mix it in with the soil prior to planting. This assures that it gets throughout the medium to counteract the acidity. DL isn't very soluble as you have noticed... even with very finely ground powder it tends to clump. Thus, top feeding after the mix isn't an effective option. Doubtful you will be able to get it deep into the pots, especially if you are using a chunkier version.

If you want to have a more immediate & effective method of raising the pH without retilling it, then you can try Hydrated Lime, again finely ground powder version. Be very cautious though as the HL doesn't cap out around ph7 as the DL, it will go up & up & up with very, very, very little added. No bs... a tblspn per 5gal will toss you up over 10.0pH. However, it is quick acting & highly soluble (get down into the soil). You will likely need to feed multiple times though & really watch your run-off pH.
Click to expand...

Good advice here. Most all peat based mixes will become more acidic over time. Adding dolomite lime to your pots isn't going to help. It takes a while for DL to break down and start working. It is best when added to your mixture before planting and then being allowed to sit and be kept moist for atleast a few weeks before using. Hydrated lime is a more immediate fix as it is fast acting. I will mix a tablespoon per gallon and then water. Then on their next watering I water with distilled water and test ph of soil. Repeat as needed until desired ph is reached.
 

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