Fungus? Purple spots

[Hero878]

There is some discolouration on my Browningia Hertlingiana but it was already like this when I bought it. They checked it over in the shop and there were no mushy bits.
Someone told me that the discolouration at the tip of the plant could be fungus. Also some of the long spines are very loose probably due to the fungus killing the tissue inside the cactus.
I hope it doesn't cause any distorted growth and that it will continue to grow this summer.
I got some organic fungicide and drenched the tip in the solution. Although the fungus doesn't seem to have spread further since I got this cactus a few months ago.
Also does anyone know if it's a fast grower compared to like Trichocereus Pachanoi?

Thank you

Photos below, if you click on the thumbnails a more detail photo will load up.

[Download]

White mildew perhaps?

I've got a Tephrocactus cutting that had creamy-white coloured spots grow on it. After moving to a drier location and using fungicide it stopped spreading. It took longer than expected to start new growth (like, I've had it nearly 12 months, got it rooted over winter under lights and started new growth last week when my other Tephrocactus started new growth at the end of spring).

It could also be mites. Just to be safe I'd use insecticide and fungicide. I also wouldn't use organic fungicide because I think it's mostly a money-wasting exercise. Copper sulfate is okayish, but it's quite poisonous. I'd use Mancozeb that's slightly safer because you can use less of it.

[Hero878]

White mildew perhaps?

I've got a Tephrocactus cutting that had creamy-white coloured spots grow on it. After moving to a drier location and using fungicide it stopped spreading. It took longer than expected to start new growth (like, I've had it nearly 12 months, got it rooted over winter under lights and started new growth last week when my other Tephrocactus started new growth at the end of spring).

It could also be mites. Just to be safe I'd use insecticide and fungicide. I also wouldn't use organic fungicide because I think it's mostly a money-wasting exercise. Copper sulfate is okayish, but it's quite poisonous. I'd use Mancozeb that's slightly safer because you can use less of it.

Thanks I will use pesticide as well as suggested better safe than sorry
I actually not usually go for organic but it was the only one available at my local garden centre. I'll look up Mancozeb though.
Fingers crossed it'll grow this summer.