How To Raise Soil ph Quickly??

[smile]

Have some plants in 5 gal buckets with Black Gold Soil and approx 25% perlite. Looks like this is a really acidic batch of soil.

Pouring ph 7 RO Water through the pots gives runoff around 2.0 EC and a ph of 5.2!!

Plants are locked up and losing leaves fast..

They need a flush to reduce ppms.

How can we get the ph back up to a normal range after the flush??

Any help is appreciated!

Thanks!!

 

[EclipseFour20]

This might help, from a pamphlet titled, Managing the pH of container media, from Univ of Hew Hampshire.

"Correcting pH Problems – Use Caution!
The following recommendations for raising or lowering
medium-pH are intended for crops already under severe stress.
Prevention of pH problems is better than relying on a cure, and
these actions are intended for crops that would be unsaleable
without some type of intervention. It is important to remember
that there is some risk associated with the handling or application
of any chemical in the greenhouse or nursery. It is up to you to
balance the risk of applying caustic chemicals to yourself or to
the crop against the potential for damage caused by high or low
medium-pH. The proper handling, mixing, and storage of
chemicals are the responsibility of the individual grower. When
applying any chemical to a plant, the authors advise a test
application on a small number of plants to check for
phytotoxicity before applying to the entire crop. When plants are
already stressed, it may not be possible to correct problems and
produce a marketable crop, even after taking these or any other
recommended actions.

5. Correcting low medium-pH
When pH falls below the optimum range, the first steps are to
(a) stop acidifying water if acid is being injected, and (b) shift to
a nitrate-based fertilizer (e.g. 13-2-13 or 15-5-15). Further action
is needed if pH has not risen within a week and plants are
becoming stressed, especially for a species in the Geranium
group when pH is below 6.0, or other crops below pH 5.4.

Consider soil drenches with either flowable lime or potassium
bicarbonate. Both materials are incompatible with all types of
water-soluble fertilizer and other chemicals, and need to be
applied by themselves as a soil drench. Other options (hydrated
lime or potassium hydroxide) have specialist uses but are less
reliable and predictable as a corrective liming material.

Several factors affect the choice between flowable lime versus
potassium bicarbonate. Flowable lime has the more predictable
and stable effect on medium-pH, without increasing medium-EC.
Potassium bicarbonate is more soluble and should be used on
flood floors or when applied through low-volume drippers. Both
liming materials are fast-acting and show most of their effect on
medium-pH within one day. Following a drench, you can
reapply after five days if pH is not up to the optimum range.

To minimize phytotoxicity from flowable lime or potassium
bicarbonate, apply in cool weather so the material does not dry
quickly on foliage; avoid splashing of foliage during application;
immediately rinse foliage with a fine spray; and apply with
generous leaching to maximize the effect at low concentration.

Tips for applying flowable lime:
• Apply at 4 qts./100 gallons (10 mL/Liter = 1:100).
• An injector can be used to dilute the solution, but the lime
particles can be very abrasive. Immediately clean equipment
after application.
• Do not apply through drippers or on flood floors because it will
clog equipment and leave residue.

Tips for applying potassium bicarbonate:
• Apply at 2 lbs./100 gals (2.4 grams/Liter).
• Can be delivered through emitters or on flood floors.
• One day after application, apply a basic fertilizer (e.g. 13-2-13)
with moderate leaching to wash out salts and to reestablish
nutrient balance.
• It is likely that repeat applications may be needed."

Source: www.greenhouse.cornell.edu/crops/factsheets/pHarticl.pdf

 

[RonSmooth]

Can you repot them in better soil?

Powdered dolomite lime can be top dressed or mixed into media. It is inexpensive as well.

 

[Mr Roboto]

dolomite lime will buffer your soil to around 7ph

 

[Apache Kush]

huh. . .so Black Gold' soil is super hot and acidic. dam shame on them, not good for cannabis grows

I saw a U-tube video of a grower in WA that mix that soil with the usual soils,
said it retains a lot of water too and thats why he mixed it in. To keep from drying to fast. You notice the slow drying at all?

Silica products are like Ph Up so try some silca too when you feed