How to raise soil ph?

I have consistently been watering 6.1 ph since beginning of grow. Plants just entered week 5 of flowering (Strain flowers in 8-9 weeks). I recently noticed runoff ph was 5.9 so I increased the ph of water going in to 6.3. Runoff is still rapidly going down, it is now 5.4 ph. Should I use dolomite lime to increase ph?

@Huganug. I was just looking for a calcium source tonight and while I was searching there were different limes. Some raised pH and some did not.

I am no expert but there are many friendly and talented growers her that are certain to jump in and help.

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Dolomite lime or agricultural lime. The more finely its ground the faster it will react. You’ll want about 1 tbsp per pot size gallon. Then gently work into top of soil.

Don’t use more than I suggested. It can cause bigger problem and could potentially turn top of your pot into concrete.


What brand soil are you using? Soil made for cannabis is PH buffered but most garden soil is not buffered for cannabis.
I had a batch of happy frog that crashed the PH down to 4.5 and found out it was an old bag from Amazon. The FFHF from the local grow store kept good PH.
My current grow I am using recycled soil and one of my amendments that I use is dolomite lime. PH in is 6.5 and out is 6.4.

Thanks! I think I’ll order some and try that.

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The soil is fox farm ocean forest. But I couldn’t find it locally so I did have to order off Amazon so I don’t know how fresh it was. I plan to get FFHF from our local feed store for my next grow. I think I’ll try a little bit of dolomite lime mixed in this time around and hopefully it isn’t an issue in the future with FFHF soil.

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