I have been reading about what cactus need for a soil and there is a lot of different ideas on this. Some books say sand is bad some say good. Others say peat and organic material will make the soil acidic when it breaks down, but most cactus mixes have large ratios of this. I have noticed that a heavy peat mix when dried out is very difficult to water. Sand seems to help but then I have read that it holds moisture and prevents airation and should be avoided. Can anyone bring some clairity to this?