I accidentally used fine sand (just the regular sand you can get for kid's play areas) in one of my raised beds. I subsequently read in several places online that you should use coarse sand. I havent tried them both, but I will say that the leaf lettuce I had planted in that bed seemed to love it, so it cant be all bad.

I made some raised beds this year and red up quite a bit on the soil mixes. After trying a few different mix ratios, here is what I ended up doing which i think is best. I bought bags from home depot / lowes instead of truck load even though i ended up buying a lot of bags by the time i was done. Instead of topsoil I used so called bags of "manure Humus" or "manure" for only $1.34 a bag. No matter what the bags said on it, I took a handfull of stuff in my had and actually looked at what is in the bag. Both of this bag types had basically small wood chips (composted) and sandy stuff. Manure if any might have been of "cow urine" origin rather than poop.

This is how I made my raised beds: dug up the original soil about 6" deep, the soil is rocky and hard clay. I layered one part "compost humus", one part sphagnum peat moss, one part above described "cow manure", one part sand (used the driveway sand" on top of each other. I dug a hole where the plant was to go in with the shovel mixing all the layers with some of original soil.

Later I discovered that it took for ever for that peat moss to "get wet". This stuff works like insulation for the water. Once it is wet though, then it retains water well.

Because of this, the second part of the beds I made, i left out the peat moss and sand. The above two types of bags I used have lots of sand in them, so i did not feel need to add sand.

Both of the beds have done well. Good plant growth.

Since you are going to use it in containers, one part compost, one part manure, one peat moss (mix them well) will work well. Peat moss by itself will retain enough moisture and don't need expensive vermaculite.