charlene.j.spence wrote:

We just bought a house with an inline fertilizer system,
( I think it's an old system) there is a big tank and a small
container connected to the irrigation system. We have no idea
of how to replenish the fertilizer or what type of fertilizer to use.
Any body familiar with this type of system or who we should call?
(We are in central Florida.) I have a picture, I just don't know
how to post it here.

Best bet is to contact a local automatic irrigation installation
company... check the Yellow Pages. They'd be able to tell you whether
the system is usable or worth rehabing.