PH Lockout ?

Here are a couple of pics. My friend has been taking care of them for a few weeks and this is what happened. They are in FFOF with about 40% perlite.
I flushed them with 5 gallons each of 7.0 ph plain (tap unfortunately) water tonight and the runoff was between 7.3 and 7.5. They have been getting half doses of Thrive alive, Grow Big, and Liquid Karma at 2/3 of their waterings (the other waterings are plain water). The first two pics are Sour Diesel and the others are blueberry and they are still in veg. (24/0). I would like to flower as soon as possible but I think this needs to be taken care of first. What should I do ? This is our first indoor grow.

Quote:

---

Originally Posted by Alexp

They are in FFOF with about 40% perlite.
I flushed them with 5 gallons each of 7.0 ph plain (tap unfortunately) water tonight and the runoff was between 7.3 and 7.5.
.

---

Good call all around.
That 40% perlite is making your life a lot easier right now ya know! :D
IF your runoff is up to 7.5 flushing with 7.0 you still have major pH probs.
You are going to want to get your flush water down to 6.2-ish if you can. Even some cider vinegar to adjust will be better than nothing.
Yes, those plants look like they are unhappy with their pH!
Keep on flushing until your runoff is 6.8.

Thanks stinky. Do I need to worry about overwatering or should I give them another flush today ? The last flush was yesterday.

After flushing with 5 gallons of 6.2 water with no difference, I switched to 4.8 (5 gallons as well) and my runoff is still 7.1. I am using a pinpoint ph meter, so I know that the readings are accurate. What should I do ?

I'm not sure of this, but I would not go much below 5.5-6 with your flush water... I think it could stress the plants... not certain though.

Quote:

---

Originally Posted by Alexp

After flushing with 5 gallons of 6.2 water with no difference, I switched to 4.8 (5 gallons as well) and my runoff is still 7.1. I am using a pinpoint ph meter, so I know that the readings are accurate. What should I do ?

---

What else can/should I do at this point? I dont want to run too much water through them (already have had close to 15 gallons. Is there something else like an additive that I can mix into the soil ?

Alex

Two materials commonly used for lowering the soil pH are aluminum sulfate and sulfur. These can be found at a garden supply center. Aluminum sulfate will change the soil pH instantly because the aluminum produces the acidity as soon as it dissolves in the soil. Sulfur, however, requires some time for the conversion to sulfuric acid with the aid of soil bacteria. The conversion rate of the sulfur is dependent on the fineness of the sulfur, the amount of soil moisture, soil temperature and the presence of the bacteria. Depending on these factors, the conversion rate of sulfur may be very slow and take several months if the conditions are not ideal. For this reason, most people use the aluminum sulfate.

Do a google seach to be able to calculate the application rates correctly.