818 Kush problems - Low Soil pH?

[Prop215Fiend]

Hi all,

This is my first time posting about this problem, it seems to happen every crop and I figure it's finally time to tackle this. This is roughly crop number 16 and I learn something every time and I love that part of this hobby.

Background on the setup is 250w C13, JiffyMix & Perlite at a 1:3 ratio, PBP Veg, FF Big Bloom Flower, Cal-Mag, Hygrozyme & Kelp. Temps are around 76-78, Humidity is 60-70%. Typically I mix up a gallon jug of 6.0pH water with 1/2-1 tablespoon of BigBloom, 5-10ml of Cal-Mag, 8ml of Hygrozyme, and 1 tablespoon of Kelp. Unfortunately, I only have a liquid pH tester and I have never been able to check the nute/h20 mixture.

The current strain is 818 Kush from clone. Right now they have been vegging for about 42 days and they are in day 3 of 12/12. This always seems to happen as soon as I switch to 12/12, the bottom leaves get really weak and fall off, start turning yellow from the outside edges and brown spots. I'm starting to notice some lighter green new growth as well, and some of the bottom issues traveling to the middle. Hopefully I can catch this problem before it gets worse.

Today I flushed with straight water at 7.0 and they all gave me a 6.0 reading coming out of the bottom of the pot. Do I need to reduce the pH more? I guess it's somewhat of a soilless mixture.

Thanks in advance

Sorry for the wet leave pics, I just doused them with neem!

 

[Guest]

If your water is 7.0 and your runoff is 6.0 it estalishes the direction acid or alkaline....

Normally with this much difference the medium is lower than your runoff....

you need to raise the ph of your medium.... you are clearly in the 5's imo

dolomite.....


You might also flush with ph 6 water and see if that drops quite a bit.....

if it does it confirms you are into the 5's

Is it true jiffy mix is only spahgnum peat and perlite or vermiculite????

Peat is way acidic.... without some dolomite its too acid....

Check your bag....


(The pH of Canadian sphagnum peat generally ranges from 3.0 to 4.5.)

 

[MynameStitch]

No do not reduce the ph anymore than what it is;

Like florigen has statedget some dolomite lime in there; cause one of the pics looks like magnesium issues...... but funny thing is you are using cal mag but how often are you using all those nutrients? ph is a issue here too so I would not feed anymore untill ph is fixed, because there could be locked out nutrients and if so you feeding to fix a defieicny could lead to other problems so fix ph first by adding lime and go from there because lime has magniseum in it and calicum so do not use the cal mag for a little bit after you put the lime in.; how often are you feeding your plants with that massive food doses?

 

[inflorescence]

Hi all,
This always seems to happen as soon as I switch to 12/12, ....

Are you using ffBB flower during the veg part. If not, then it's dropping your pH lower than when in veg where you don't use it.
Most all flower nutes are notorious for lowering the pH more so than their veg counterparts.
I think it's all the Phos they use in the bloom ferts, they add it in as as a form of phos that is basically like pH down.

 

[Prop215Fiend]

If your water is 7.0 and your runoff is 6.0 it estalishes the direction acid or alkaline....

Normally with this much difference the medium is lower than your runoff....

you need to raise the ph of your medium.... you are clearly in the 5's imo

dolomite.....


You might also flush with ph 6 water and see if that drops quite a bit.....

if it does it confirms you are into the 5's

Is it true jiffy mix is only spahgnum peat and perlite or vermiculite????

Peat is way acidic.... without some dolomite its too acid....

Check your bag....


(The pH of Canadian sphagnum peat generally ranges from 3.0 to 4.5.)

Thanks for the reply!

Actually I did initially run some 6.4 ph water and got the same 6.0 reading. My pH tester bottoms out at 6.0, but it did seem register "lower" than the 7.0pH water.

I believe you are correct, http://www.doityourself.com/invt/1329457. Mix of peat moss and vermiculite.


Would Oyster Shell Lime work? If it's too late to add to the soil mix, can I apply as a top dressing and water?

 

[inflorescence]

oyster shell is way too slow acting. You need very finely powdered dolomite at this stage, even better would be hard water or liquid lime.
Or mix the dolo powder in you water a day or two before you use it, let it dissolve then water your gals.

 

[Guest]

Oyster lime is too slow.... me too on the post..... lol....

top dressing doesnt work that well.... but it would help......

the dolomite would need to be mixed in the soil for best results...

I would suggest another ph tester..... you need something down to 5.0

 

[Prop215Fiend]

No do not reduce the ph anymore than what it is;

Like florigen has statedget some dolomite lime in there; cause one of the pics looks like magnesium issues...... but funny thing is you are using cal mag but how often are you using all those nutrients? ph is a issue here too so I would not feed anymore untill ph is fixed, because there could be locked out nutrients and if so you feeding to fix a defieicny could lead to other problems so fix ph first by adding lime and go from there because lime has magniseum in it and calicum so do not use the cal mag for a little bit after you put the lime in.; how often are you feeding your plants with that massive food doses?

I usually feed twice, then water with plain water. I agree about trying to compensate a problem without knowing what it really is.

I actually used a 1/4 of the bottles suggested dosage. I figured the RO water would need the additional cal-mag.

Thanks for the info stitch!

 

[Prop215Fiend]

Are you using ffBB flower during the veg part. If not, then it's dropping your pH lower than when in veg where you don't use it.
Most all flower nutes are notorious for lowering the pH more so than their veg counterparts.
I think it's all the Phos they use in the bloom ferts, they add it in as as a form of phos that is basically like pH down.

Yes that is my one error that I admit to doing on this run. I didn't know that but it makes alot of sense!

thanks so much for replyin!

 

[Prop215Fiend]

oyster shell is way too slow acting. You need very finely powdered dolomite at this stage, even better would be hard water or liquid lime.
Or mix the dolo powder in you water a day or two before you use it, let it dissolve then water your gals.

Hmm, well I have plenty 8.0 out of my tap! lol. Would that work?

 

[Guest]

i've ran 818 more than anything else and she is a pain but great herb. took me 2 runs to really dial her in. also i'm not sure what you're using to test ph, but if it bottoms out @ 6 i would seriously consider getting yourself a proper ph pen. i think that would really help u fix her. good luck

 

[Prop215Fiend]

Oyster lime is too slow.... me too on the post..... lol....

top dressing doesnt work that well.... but it would help......

the dolomite would need to be mixed in the soil for best results...

I would suggest another ph tester..... you need something down to 5.0

Agreed. a pH and PPM tester are some of the final things I need. Digital ones at that!

 

[Prop215Fiend]

i've ran 818 more than anything else and she is a pain but great herb. took me 2 runs to really dial her in. also i'm not sure what you're using to test ph, but if it bottoms out @ 6 i would seriously consider getting yourself a proper ph pen. i think that would really help u fix her. good luck

Oh wow, thanks for the info. I agree I need a pH pen ASAP. I wish they have inexpensive ones locally. All the hydro shops want like $70+ for one, otherwise it's wait for shipping online which sucks.

What pH's do you typically run, are u soil or hydro?

 

[Guest]

hell yeah man. the pens are pricey, but they are so key. i mean everything depends on it so save up and get a nice one.

i ran her in ff ocean forest with a bunch of chunky perlite added. i use a ph anywhere from 5.8.-6.4. i'm not real exact in dirt as i am in dro. all i use is bigfoot nutes w/ sensizyme and just a tiny bit of cal-mag cuz I use "cured" tap. they took 1k ppm's and coulda took more for sure. all this talking about her makes me want to smoke it

 

[Prop215Fiend]

hell yeah man. the pens are pricey, but they are so key. i mean everything depends on it so save up and get a nice one.

i ran her in ff ocean forest with a bunch of chunky perlite added. i use a ph anywhere from 5.8.-6.4. i'm not real exact in dirt as i am in dro. all i use is bigfoot nutes w/ sensizyme and just a tiny bit of cal-mag cuz I use "cured" tap. they took 1k ppm's and coulda took more for sure. all this talking about her makes me want to smoke it

haha I know what you mean, I can't wait to harvest some!

What do you mean by "cured" tap? I was worried that SoCal tap is too high in pH.

That's great info tho, thank you so much for sharing.

 

[Guest]

Well since I use LA tap water I let it sit out for at least 2-3 days before i mix in my nutes. It helps with getting rid of some of those unwanted elements and i find the ph is much more stable. If you use socal tap I would really recommend you give it a try

 

[sativalicious]

if one considers how much is money invested in minimal hobby system, a $200 meter to do pH, EC, and TDS is not a big deal. And when you consider that when you run a system that is not tuned, pH wise, you are running an inefficient system. Hence, money is flying out the window in terms of under-utilization of resources like electricity every hour. So, might as well spent the $200 on a decent meter.

Regarding water and evaporation, isn't that becoming somewhat like an urban myth? I heard many water systems use Chloramine which does not evaporate like the old school Chlorine, did. Pls correct me if this is does not hold a truthiness test.

 

[Guest]

Well I get sent a report from the LA DWP that shows you an average of the elements in the tap water here. Chlorine is one of them. You can smell it. I'm not sure how much or if anything burns away but I can tell you my ph has much less swing and i've had much less issues with lockout. i'm no expert though just giving my

 

[Prop215Fiend]

Yeah I just checked the DWP report, but didn't see any mention of Chloramine.

The pH seemed high tho, 7.8-8.2 it claims. I typically let any tap water sit for 1-2 days before use.

Should I just keep flushing with clean water for a few more waterings, or is a light flower fert ok?

Thanks again yall.

 

[sativalicious]

Not being a chemist, I wonder why the pH seems to settle after the water has been sitting for a couple of days. I see it settle from about 9.1 to 8.8 where it stops. I pay attention to the pH of the solution going in.