Is this right if you make your own you use 50/50 ordinary potting mix and coarse sand.

It's getting about time I replant my barrel cactus.
Another question it's about 15 years old. How long do they live?

Edit: I will buy a bag of Cacti and succulent mixture. Found this to might be of interest to others.
Spiky cacti can be handled painlessly. Small cacti can be managed with kitchen tongs. But if you have a bigger cactus, the trick is to make up some ‘hands" out of a foam box used by fruit shops. Carefully cut up a foam box so you keep one of the corners attached to two sides, and you have a good, safe cactus-handling device.

Cacti love sun. Water them once a week, and give them a weak quarter-strength dose of slow-release fertiliser in spring and summer.

1:1 potting soil:drainage material is a very quickly draining mix excellent for many succulents. For the drainage material I use all sorts of stuff. Coarse sand is good, as long as it really is coarse. I also use grit and gravel that I sift out from bags of 'traction sand' I get at the hardware store in winter, aquarium gravel, small lava rock (I don't use too much of this because it is expensive at the garden store), grit I sift at beaches and clean really well, whatever. Cacti & Succulent mix from the store has pearlite, for which I have a personal negative bias, but some people don't mind it. As for the longevity of your cactus, if you treat it well, your grand kids will show it to their kids, who may watch it pass, or not.

Hello margaret e. pell
Thanks for the info.

Well this is what I went out today and came back with, I now have two new pots for my barrel cactus's and store brought Cacti & Succulent mix.
I didn't see anything on it about pearlit but it has blood and bone, Zeolite and silica.
I plan to put small pebbles at the bottom about 2cm thick and cover the top of the mixture around the Cacti with pebbles.

So hows that sound?

Sounds great! Bone is good, cacti need calcium. Remember that any top dressing will prevent you from seeing how wet or dry the soil underneath is, or poking a finger into it. I also set my pots on top of several soda bottle tops so I know when the water has drained through and the pot does not sit in any runoff. Anyway, if you've had it for ~15 years, you know what you're doing.

All done they did need the replant they look much better in the new pots

I used top dressing so I will just have to keep more of an eye on them.