Cynj,
Farfard actually does have a cactus and succelnt mix.
Look online, they do sell it, just in case you are interested.
For my citrus, I use Miracle Grow Citrus and Cactus mix.
It's growing just fine.
I use Farfard Professional Potting mix for all my other plants, my plummies go in Cactus mix.
If your local nursery doesn't have it, (most regular nurseries do have it), you can ask them to order some for you.
I tried Al's mix one year, it was fine, but I had to water almost every day. I'm not watering every single day, all my plants. I'm not saying it isn't good, everyone has a different tolerence for things.
I also use Foilage Pro, by Dyna Grow, I dilute it 1 teasp. per gallon of water, and every time I water, they get a little Foliage Pro too.
Foilage Pro is awesome! A little bit goes a long way too, so even tho it is a little pricey, you don't use that much.
I use it on all my plants, even orchids love it!
Hope I helped a little bit.