You need more "basics" - salwater life needs stability - ph of 8-8.5 - salt doesn't evaporate, freshwater top off to keep stable salinity - w/c's of at least 10% weekly for stable buffering capacity Yes, yes, and yes.- increased water circulation as calcium, magnesium, and salt can fall from solution Unless he's planning on freezing his water solid, precipitation is hardly a concern. I'd be 10x more worried about the buffer solution et al precipitating out in their containers than in the tank. Besides, circulation wouldn't prevent that anyways.- lighting for corals , LED or 10,000K as they generate some of their own food (photoplankton) There's more than one optional lighting source for corals (and what you've listed was only one lighting option and a light color? Intentional?) T5's (my favorite), Power Compacts, Metal Halide, along side LED. LED is the most expensive, followed by Halide, but the put out the best quality light. T5's and PC are about the same price but T5's are considerably better IMHO and a 6+ bulb configuration is satisfactory for pretty much any coral in all but the deepest of tanks. And some combination of 10,000, 14,000, 16,000K lighting with an actinic back up is usually the coral light color of choice. The specific configuration depends on whether you want growth or color or some intermediate.- A heater is a must, salinty fluxates with tempature changes, Benifical Bacteria(BB) grows faster in temps of 78-80. More surface area for BB, your tank should have at least 1/3 it's total volume as pourous calcium rock either live or base. A test kit is a must as cycling saltwater tanks takes 4-8 weeks after that corals and inverts need specific calcium, magnesium, alkaline, and super low phosphate parameters. Some corals and inverts cannot survive in water with alot of dissolved protiens - hence for corals a good potien skimmer is a must.
With 1 Live rock - 2 fish and 2 hermits ,uncycled tank, inadaquet BB filtration, poor water circulation, sub-standard lighting, and no heater your "basically" lookin' at an Algae, Parasite, Harmful Bacterial, and Poisonous gas breeding ground that cannot support marine life. Maybe take the fish and hermits back and start over - sorry if this isn't what you wanted to hear but I call'm like I see'm.