Hydrated Lime
By Bulbaholic
Moray,
Scotland 
A nurseryman friend has told me that hydrated lime from the Builders Merchant is the same stuff as garden lime from the Garden Centre but much cheaper.
Does anyone know if this is true or, if not, can the Builders Mechant stuff be used in the same way without harming the plants?
26 Feb, 2009
Answers
i was about to tell you it was stronger but didnt know off the top of my head by how much. now i know i dont have to research it. thanks bh. :-)
26 Feb, 2009
Hi Bulbaholic - I'm sure you'll be careful when using but remember to protect your eyes.
26 Feb, 2009
Thanks for your concern, ladies, and yes I will be careful.
26 Feb, 2009
I have just answered this myself from the RHS website.
Hydrated lime can be used in place of garden centre lime but is stronger. For example instead of using 6oz of garden centre lime you would use 4oz of hydrated lime. A 25Kg bag will go a long way!
26 Feb, 2009