No rust infection there @Familyman and you didn’t have needed to flush either, your plants add nothing at this point that the fact that FFOF is a hot soil and everything would replace itself after 2 - 3 weeks…
These symptoms are really common on FFOF user’s, that’s why I always recommend to transplant later in vegetative stage to transplant in FFOF, or made layers of soil, less hot on top like FFHF (FoxFarm Happy Frog) or a cactus soil on top of the FFOF , half an half…
By flushing and began your sulfur powder treatment, you create a nutrient lock out right there… And all the symptoms of cal\mag deficiencies that your plants are showing today are the result from this date…
Let dry your soil until your pot are light and your soil dry at least 3 inch from the top of your soil… And resume only water regimen until later in vegetative stage, FFOF has everything in it to support the plants needs.
In hope that’s helping you figure this out…
~Al External Media️ External Media
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