The water is collected directly from the shore. If it smells or isn't crystal clear I don't collect it at all. I didn't have any problems due to pollution but once I got a micoalgae bloom that required an almost total water change to get rid off. Our public aquarium and other aquarists collects water there too.
I use only natural seawater and do regular water changes. I don't use any kind of suplementation besides Calcium and kalk reactors. I think that the replenishment of trace elements and some live plankton make corals grow faster.
New photos:
Durso standpipe and Tunze turbelle 7240/2 (18gph)
Sump: DIY skimmer, 300W Jager heater, Tunze osmolator with Calcium dispenser and 12gal RO/DI water reservoir, return pump Eheim 1262 (900gph)
Next: lighting
Ricardo