I can't get that in the UK, well I can, but it is too expensive.It does take a bit for the plants to uptake the calcium, but it neutralizes the acidity almost immediately.
There's lots of kinds though, and I used the epsoma from Home Depot. It dissolved quite a bit when I watered it in and seeped down into the soil.
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Garden Lime Powder Soil Conditioner Limestone Dolodust Tubs | eBay UK
If there has been no rain it is advised to water the application into the soil, but be careful as too much water, could wash Nitrogen out of the soil as well. Dolodust is an effective way to increase the pH of soil, especially in areas where the soil is more acidic than normal.
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