A. Dean Stock wrote:Your water is very likely to be at least slightly alkaline. That if the correct MSU fertilizer at RePotme. I'd buy the one for tap water and also get the granules not the liquid unless you just like paying them for their water and higher shipping weight. The fertilizer may lower your final watering solution pH some but I'd test it to be sure. Use a very dilute fertilizer solution (like 1/2 tsp/gal. of the granular mix to your watering solution. If your water is very hard with a heavy load of salts you might be better off using R/O water, in which case you would buy the fertilizer designed for RO. Your local water company will supply you with water hardness and pH (usually).
The MSU granular fertilizer is fine, so I would have no problem diluting it with my own water. L.A. DWP issues water quality bulletins on a regular basis (it's either once or twice a year), and they're very thorough. I'll need to verify pH in case I may need to get a pH tester. Since our water is hard, I'll get the most recent DWP bulletin to see if there's any data on salt load. I'd be surprised if this is a problem. Hopefully not, because if it is, the only room I can put in my collection comprises all of a 5' by 1 1/2' space, and there's no way I can justify the expense of an R/O system simply for that. I have been using a solid carbon block filter for years. It filters down to .5 microns, so I get only pure water and minerals. I'm wondering if that would have any mitigating effects on a heavy salt load, although I suppose salts and minerals are the same here. (If you're interested, the system is Multi-Pure.)
promethean_spark wrote:Some cacti live in pure fine dirt/clay, others live in stuff like decomposed granite. You can look at pictures of habitat to get an idea of what a species might like.
Mesagarden pretty much exclusively uses dirt from their property for their plants. It's probably pretty similar to california hill-soil. I've had pretty good results with yard soil with larger cacti species in 1g pots, but they're mainly easy stuff like echinopsis. Regular dirt doesn't drain as well, so it's less forgiving of overenthusiastic watering.
I've been trying to examine as many options as possible. In fact, I spent a fair amount of time on the phone earlier today, but all I get are dead ends for anything beyond the usual sources here in the greater L.A. area. I'm not totally giving up yet, so there's one more person who may be able to help me. If you're interested, I'll report my results at viewtopic.php?t=24122