I apologize...did you use that sea water collected from dude? Or did you get RODI Salt water? If the you got RODI saltwater, or just RODI and mixed with salt, you will be OK. I honestly wish you would get a refractometer, (they are not expensive), and your results will be accurate...but before doing any more changing or adding water...please use the refractometer to ensure Specific Gravity...you might be shocked.
Another thing...the 'Chain' you mentioned traditionally does not have healthy fishes for the most part for several reasons...the Mgt will not let them do but so much...the water they use is not RO let alone DI, and I believe it's simply purchased from Culligan Water. (or at least here that's the case)...also most of those who are working in the aquatic section are not up to par on the correct way for fish husbandry with the exception of a friend of mine who was in charge of the area and him being a Marine Biologist which helped. But certainly not the norm, just the exception...and testing your water with 'strips'...OMG man, come one...HUGE RED FLAG. Please do yourself a favor and buy at the least a simple basic test kit. API is eh...but better than what they did for you.
Good luck, and please keep us updated. I'm sure several would like to get you on the right track with a nice heathy system.