Here is a recipe. Not recommended. Too much trouble and probably cheaper to buy a commercial product.
"PeterÂs" formula for soaking bark to treat one 50 litre bag

Urea - 130 Grams

Dolomite - 35 Grams

Potassium Sulphate - 25 Grams

Ferris Sulphate - 35 Grams

Copper Sulphate - 10 Grams

Soak bark in this mixture for 10 days. Treatment provides some nutrients and reduces acidity so that orchid roots are not damaged.

Pine bark is not generally used for orchids as it breaks down quickly. Fir bark is much better.

Agree, Fir Bark is better! But it is scarcer than Hen's Teeth around these parts, so the major ingredient in potting mixes is treated pine bark.

Hi everyone,

Thanks for the feedback to my question. I forgot to mention in my first post that the bark was to be used for growing bromeliads and not orchids, however that didn't alter the question.

I think arthurm gave me the info I needed although I will leave out the copper sulphate as copper is fatal to bromeliads.

I agree with both orchid126 and arthurm. I learnt years ago when I grew orchids, that fir bark was far superior to radiata pine bark, but the cost is very expensive and as arthurm says, it's as scarce as hen's teeth around here, so we just have to adapt and make the best of what we have.

All the best, Nev.