This idea is demented. If you do this several years in a row, your soil will eventually not grow anything and the water table will become polluted with one of the most expensive contaminants - - salt.
Something similar happens when you irrigate year after year with hard water. The minerals accumulate in the soil eventually poisoning it.
Organic pollution eventually breaks down over time. Salt will never be anything but salt.
Plant you tomatoes in high salanity soil to begin with and then water with normal water, huh?
Exactly what I was thinking. I fertilize with a good high quality, low nitrogen, fertilizer which contains all the trace elements necessary for a healthy plant. I also use prodigious amounts of bone meal.
Fish emulsion is not a balanced fertilizer and has too much nitrogen for tomatoes.