Substrate questions

The folks of the Vancouver Aquatic Plants Group would like to know what the
concensus is out there on how long a substrate lasts?

If one uses laterite, is it good for many years? If one uses soil, peat
etc. how long are the nutrients good?

Also, has anyone bought and used the "laterite" red potting clay that
ceramic places use? And if so, what's the verdict?

Thanks for any answers.
in Vancouver