Absolutely 

I learned the hard way.after 3 months or more of feeding there is a lot of leftover nutes in the soil 

i usually re-use my soils several times..i add worm castings and re-charge sometimes to the used soils and i also add cal/mag in waterings...and i use the fox farms nutes...there is a lot of trace elements in fox farm soils that remain IMO...seems to werk fine for several grows...if i see issues start to form after a few grows i put the soil outside in my landscaping projects....