The first question is how long have you had the tank set up?
Cloudy water can come from several things. The most likely ones are -
Fine particulate matter in the substrata. This is very common with new systems.
An algae, diatom or bacteria bloom. Another common problem with new systems.
Something big has died in the tank. Check for any missing fish, dead corals and so on.
Except for something being dead, most of these problems will go away on their own if just left alone. In looking at your tank pictures your problems don't look too bad.
Usually a good skimmer and filtration will help to solve cloudy water issues. Make sure they are dialed in correctly.
It's possible your goby is disturbing the sandbed. Some species really like to dig, but this is not necessarily a bad thing, as it helps keep the sandbed clean.
If you have a chronic problem with algae or bacteria blooms a UV unit can help, but don't be in any rush go out and get one. They are expensive and of limited value beyone this. Only go this way if your have no other choice.
Lighting by itself is unlikely to cause an issue, but can cause algae or diatom blooms. You can try cutting it back.
The bottom line, as long as the fish and corals are ok, leave things along for a few weeks and see if they improve.