San Pedro Cacti Soil Experiment

There’s a ton of different recipes for soil mixes for cacti in general. Mainly what ingredient you should use as the porous substance.

I am planning on doing a “scientific” experiment on what substrate these cacti respond to best.

My idea:

Control Group:

100% Cacti & Succulent Mix (store bought)

Group 1:

50% Cacti Soil Mix 50% Perlite

Group 2:

50% Cacti Soil Mix 50% Pumice/Lava Rock

Group 3:

50% Cacti Soil 25% Perlite 25% Pumice

Group 4:

50% Organic Compost 25% Sand 25% Pumice

All groups will be given the same lighting conditions, same watering schedule, and same pots.

What are your thoughts? What should I add or remove?

I’m sure there are tons of holes in the experiment, and that’s why I say “scientific”. It’s modeled after an experiment, but not as rigorous, which for our purposes I don’t think it really needs to be.