Tank transfer didn't go well

[High tide]

I have never used Deltec salt, but I know some salts take a couple days to dissolve properly. Flow changes would not trigger RTN throughout your tank. Unless there is some information you left out, the stress of the transfer and a 40% water change with freshly mixed salt resonates. I never do a water change when I transfer a tank, too much change at once is detrimental to SPS. Ideally you would have started the new tank slowly with some water from your old tank and some live rock, while doing small fresh water change in your established tank prior to transfer.