Very High Soil Ph

[JackD]

I'm on my second grow. The first one went ok and I ended up with about a pound of bud from 8 plants, but I had several instances of brown spots that damaged quite a few leaves. I thought it was Ca or Mg def because the issue got better after I started supplementing with CalMag Plus, since I was using Jack's Classic that doesn't have any Ca or Mg.
This time around, I'm using Dynagrow Foliage Pro, which does have Ca or Mg, so I haven't added CalMag yet.
I've got 6 plants grown from clones that have been in veg for about 3 months. They are only about a foot tall, because I intentionally had them growing slow by having them in small pots in a cabinet with CFLs while I waited for my first grow to finish flowering.
I transplanted them from 1 gallon pots to 5 gallon fabric pots and moved them under my 600w MH about a week ago. They are starting to show just a few brown patches and slight yellowing between the veins on a few of the older leaves. At first I assumed they weren't getting enough Ca or Mg, but then I figured I should test ph of the soil itself.
The soil I had them in when they were in the 1 gallon pots is some random organic potting soil from Walmart. It's the same stuff I used throughout my first grow. The soil I transplanted them into is organic potting mix from Lowes. Both have at least 30% perlite added.

So I took a spoonful of soil from the original root ball, right around the stem, threw it in a jar, added distilled water, shook, and waited about 10 minutes. I did the same thing with some of the new soil they were transplanted into.

The original soil in the rootball is testing at ph 9.2.
The new soil is testing at about 7.2.

My water source is tap that sits overnight, around ph 8, and 70ppm.
I add 1/8 tsp of protekt silica per gallon and 1 tsp of Foliage Pro per gallon, then usually have to add a little ph down to get to about 6.5 before watering. I'm feeding with every watering, around 400 to 500 ppm.

So the questions are:
Should I be concerned about my soil ph being so high?
Is this a likely cause of lockout issues?
What can I do to correct it?

I was thinking I could lower the ph of my water closer to 6.0, but I don't know if that will have any lasting impact on the soil ph or if it will just cause more problems.

 

[Enforcer]

Yes and yes. You can lower you input ph to about 5.5 the next few waterings to nudge the soil ph down. Or you can scratch in some garden gypsum (elemental sulfur) to the top of the soil. Which will lower the medium ph over time.

 

[JackD]

I misspoke a little in my first post. I had moved my plants under the 600w MH about a week ago, but I realized it had only been a couple days since I actually transplanted into the 5 gallon pots. So I was able to pull them out with the original root ball intact, gently shake off most of the original high ph soil, and put them back in the 5 gallon pots with more of the new soil that tested at 7.2. Hopefully having a soil ph of 7.2 and dropping my water to around 6.3 should be ok. I'll see how they do over the next week and reevaluate.

 

[oldskol4evr]

dont have a picture,but if they are under 3 sets of leaves,you can ease the rootball into a cup or bucket water and let the soil disolve around your roots,then throw in some root better or root powder,walmarts shit as good as any,,but put some that in your hole,then put your roots and ball back in the good soil,if they are that small its worth it,now is better than down the line when these girls gett to swanging them hips,hahah

 

[Homesteader]

Or you can scratch in some garden gypsum (elemental sulfur) to the top of the soil. Which will lower the medium ph over time.

Gypsum is not the same as elemental sulfur and it will not affect pH in most cases.

I would recommend top dressing 100% peat and use gypsum to fix any cal issue in the future. Peat (Sphagnum moss) usually has a pH of 4.5-5.5, if you scratch some in it will bring down your pH to a manageable level. Cheap enough at the box store.

 

[Enforcer]

Gypsum is not the same as elemental sulfur and it will not affect pH in most cases.

I would recommend top dressing 100% peat and use gypsum to fix any cal issue in the future. Peat (Sphagnum moss) usually has a pH of 4.5-5.5, if you scratch some in it will bring down your pH to a manageable level. Cheap enough at the box store.

You’re right. Thanks for setting me straight. For some reason I was associating gypsum as the common name for elemental sulfur, which is what I was saying will lower ph.

 

[JackD]

dont have a picture,but if they are under 3 sets of leaves,you can ease the rootball into a cup or bucket water and let the soil disolve around your roots,then throw in some root better or root powder,walmarts shit as good as any,,but put some that in your hole,then put your roots and ball back in the good soil,if they are that small its worth it,now is better than down the line when these girls gett to swanging them hips,hahah

They are very bushy with lots of branches and leaves. I had them vegging in a small cabinet for about 10 weeks because they were clones I took from my first grow right before flipping the first set of plants to 12/12 and didn't move them until I harvested the first plants. They are short because they were only under 4 23w CFLs and I LST'ed them. Good idea about soaking in water, but I've already removed most of the original soil now and hopefully didn't cause too much trauma for them to recover.

While these plants were in the cabinet, in addition to using Foliage Pro, I was also using Silica. I know that stuff raises ph, but I always used ph down to get it back to 6.5 before watering. But I wonder if the silica stays in the soil longer than the ph down and might be the reason the soil ph got so high this time.

 

[oldskol4evr]

They are very bushy with lots of branches and leaves. I had them vegging in a small cabinet for about 10 weeks because they were clones I took from my first grow right before flipping the first set of plants to 12/12 and didn't move them until I harvested the first plants. They are short because they were only under 4 23w CFLs and I LST'ed them. Good idea about soaking in water, but I've already removed most of the original soil now and hopefully didn't cause too much trauma for them to recover.

While these plants were in the cabinet, in addition to using Foliage Pro, I was also using Silica. I know that stuff raises ph, but I always used ph down to get it back to 6.5 before watering. But I wonder if the silica stays in the soil longer than the ph down and might be the reason the soil ph got so high this time.

i transplant all kinds friend,lmao too much really,but ya always check them bags,sounds to me you got a self feeder i guess they call it these days,say 3months to 6 month feed,ya that for tomato plants,and the shit dont work i will add,only way you got that high was doing something wrong,no sure,but looks like you check the new stuff and run wit it,,my best soil mix,goes like this for outside garden,1:1:1,5 gal ,peat moss,5 gal manure compost,2 1/2 gal perlite,2 1/2 vermiculight,2 cups blood meal,2 cups bone meal,1 cup azomite,and roll with it,dont even check ph of water or soil,this is a recipe to put herb in the chest and food on the table,hahahah,when i grow special shit i use ocean forest,i feed humic /fulvic acid,steel cut oats ,oat grain,barley malt powder,aleo vera,coconut water some times,the humic and fulvic ,keep shit working and the rest is food,all i feed my babies