Top Soil or Sand????

[BCLS]

I have a few questions for those of you with more experience with this topic.

I have several customers that have asked me to level or redirect drainage using sand or top soil. Being this is not my specialty I'm asking you all what would work better.

I have seen sand being used but was not sure if this application serves every purpose.
Will applying sand on to a grass established area to fill in be bad and kill of the grass or will top soil be better.

Please explain to me how you go about using the two and which types of applications.
Also, if using sand for leveling or filling in low spots what type of sand is better suited for this type of fix.

Thanks everyone and I would greatly appreciate your inputs on these questions.

Edward
Bayou City Lawn Services

[mariner]

Sand does not hold water well. It is good for drainage but is not a good stand alone medium for growing grass. You'll get a lot of weeds in sand. Sand is good to add to an area that is soggy but should be tilled in.

[work it]

You'll find that sand is usually used on sports fields, but isn't recommended for areas that don't have irrigation systems. You'll notice that they constantly have to water sports fields. Just as mariner mentioned, it can't retain water. As for top dressing with soil you need to make sure that the soil your applying is compatable with the existing soil. If it's not then you're going to create problems due to layering.