GodBud
11-11-2009, 08:14 AM
Quoted from Site
Adjusting pH Of Marijuana Grown In Soil
A good way to stabilize soil is to use dolomite lime (calcium-magnesium carbonate). Dolomitic lime acts slowly and continuously, so soil will remain pH stable for a few months.
Using fine size dolomite lime is important, coarser grades can take a year or longer to work. You can find fine size dolomite lime at any well stocked garden supply center.
Dolomite lime has been used by gardeners as a pH stabilizer for many years. It has a pH that is neutral (7.0). When added to soil in the correct proportions, it will stabilize soil at a pH near 7.0.
When growing in containers, add one cup of fine dolomite lime to each cubic foot of soil. Mix the dry soil thoroughly with the dolomite lime, then lightly water it. After watering, re-mix it and wait for a day or two before checking the pH. When growing in an outdoor garden, follow the dolomite lime manufacturers instructions.
Lowering soil pH: small amounts of composted leaves, cottonseed meal, or peat moss will lower the pH of soil.
Raising soil pH: small amounts of hardwood ashes or crushed oyster/egg shells will help to raise the soil pH. Hydrated lime can also be used to raise the pH of soil. In containers, use no more than 1/8 cup of hydrated lime per cubic foot of soil (per application). Mix it into warm water, then apply the water to the soil. When growing in an outdoor garden, follow the manufacturers instructions.
Wait at least a day or two before checking the pH level of soil after attempting to raise, lower or stabilize it. If adjustments still have to be made, use small amounts of whatever material you are using. Don't try to adjust the pH more than 0.1 every two days.
My situation
I have tested my Ph runoff and its very low. I used a digital meter and some strips and the meter says 4.3 and the color of the runoff after adding the Ph solution at 4 drops shows the color to be lighter than the 6 via the color chart. So I am thinking that the Ph is in the mid 4s
I have a 3 gal pot using promix bx soiless medium. I am using Canna Terra Flora 2 2 4 and I am in week 5 flowering. From the top down the leaves just around the cola have burnt goldish edges and then there are a few fan leaves below that with same symptoms. Everything below that all leaves look good and healthy.
Temps are 82 Degrees F Humidity is 60% Using 400W HPS
Based off the info on the site I thought it was heat stress but went ahead and did a ph runoff test and found that the ph is low. Now this is assuming my digital meter is right. I have had it for a few years and havent had it calibrated but I dont know a good way to test it so I bought the strips but as stated they both seem to be pointing the same direction that its low and not in the prime zone. So this could be a lockout issue.
I want to get the Dolomite Lime or Hydrated Lime but I am not sure how much to apply. It has been stated Use 1/8 cup of Lime per cubic foot but I dont know if I have a cubic foot of soil in my 3 gal container. I guess what I am asking is how much Lime would you add to a 3 gal container. Its not completely filled to the top but definitely 3/4 or better. It is stated to mix with warm water and apply to soil, can you add nutes during this application? I am assuming that you mix the dolomite in the warm water and test the Ph before adding to the medium is this correct?
It seems to me that the PK amounts on the Canna are low but I used it on my last grow with awesome results. I am thinking this is a lockout issue but makes me wonder why only the top of the plant looks affected. One thing is for certain I know I need to get the Ph in check. I just need a little guidance on how much Dolomite to add based off the size container I have.
Any feedback is greatly appreciated!
Peace
Adjusting pH Of Marijuana Grown In Soil
A good way to stabilize soil is to use dolomite lime (calcium-magnesium carbonate). Dolomitic lime acts slowly and continuously, so soil will remain pH stable for a few months.
Using fine size dolomite lime is important, coarser grades can take a year or longer to work. You can find fine size dolomite lime at any well stocked garden supply center.
Dolomite lime has been used by gardeners as a pH stabilizer for many years. It has a pH that is neutral (7.0). When added to soil in the correct proportions, it will stabilize soil at a pH near 7.0.
When growing in containers, add one cup of fine dolomite lime to each cubic foot of soil. Mix the dry soil thoroughly with the dolomite lime, then lightly water it. After watering, re-mix it and wait for a day or two before checking the pH. When growing in an outdoor garden, follow the dolomite lime manufacturers instructions.
Lowering soil pH: small amounts of composted leaves, cottonseed meal, or peat moss will lower the pH of soil.
Raising soil pH: small amounts of hardwood ashes or crushed oyster/egg shells will help to raise the soil pH. Hydrated lime can also be used to raise the pH of soil. In containers, use no more than 1/8 cup of hydrated lime per cubic foot of soil (per application). Mix it into warm water, then apply the water to the soil. When growing in an outdoor garden, follow the manufacturers instructions.
Wait at least a day or two before checking the pH level of soil after attempting to raise, lower or stabilize it. If adjustments still have to be made, use small amounts of whatever material you are using. Don't try to adjust the pH more than 0.1 every two days.
My situation
I have tested my Ph runoff and its very low. I used a digital meter and some strips and the meter says 4.3 and the color of the runoff after adding the Ph solution at 4 drops shows the color to be lighter than the 6 via the color chart. So I am thinking that the Ph is in the mid 4s
I have a 3 gal pot using promix bx soiless medium. I am using Canna Terra Flora 2 2 4 and I am in week 5 flowering. From the top down the leaves just around the cola have burnt goldish edges and then there are a few fan leaves below that with same symptoms. Everything below that all leaves look good and healthy.
Temps are 82 Degrees F Humidity is 60% Using 400W HPS
Based off the info on the site I thought it was heat stress but went ahead and did a ph runoff test and found that the ph is low. Now this is assuming my digital meter is right. I have had it for a few years and havent had it calibrated but I dont know a good way to test it so I bought the strips but as stated they both seem to be pointing the same direction that its low and not in the prime zone. So this could be a lockout issue.
I want to get the Dolomite Lime or Hydrated Lime but I am not sure how much to apply. It has been stated Use 1/8 cup of Lime per cubic foot but I dont know if I have a cubic foot of soil in my 3 gal container. I guess what I am asking is how much Lime would you add to a 3 gal container. Its not completely filled to the top but definitely 3/4 or better. It is stated to mix with warm water and apply to soil, can you add nutes during this application? I am assuming that you mix the dolomite in the warm water and test the Ph before adding to the medium is this correct?
It seems to me that the PK amounts on the Canna are low but I used it on my last grow with awesome results. I am thinking this is a lockout issue but makes me wonder why only the top of the plant looks affected. One thing is for certain I know I need to get the Ph in check. I just need a little guidance on how much Dolomite to add based off the size container I have.
Any feedback is greatly appreciated!
Peace