From what I gather the Mt Sylvia is cleaner but has a slightly alkaline ph at 8.6. (quoted from Mt Sylvia website)

Sorry Damien for not replying sooner , I use 50/50 Diatomite and sieved Searls premium potting mix and I have 2 Azaleas still floweringDamian Bee wrote:Thanks Barry. Have you been using it straight on your azalea or are you mixing it with other ingredients?