the lighting will be a part of your problem, the AI 16 is a nano light, IMO it maxes out at about 25 gallons. I have AI 16 on my 15 gallon set at 70%. Your tank should have probably 4 of them, but stronger lights is better than several weaker lights IMO
We are replicating the ocean, so the water should flow, it should move from one side of the tank to the other. My 40 gallon has 2 gyres. Without flow, detritus will build up in dead spots and build up nitrate, algae loves low flow tanks, corals need flow to bring them nutrients and oxygen and to help clean them. Your size tank should have strong powerheads to move the water, flow is very important in a saltwater tank.
You should also have a powerhead pointed at the water surface, the surface should be well agitated. This help gas exchange and will help oxygenate the water.
For corals, its all about lighting and flow and nutrients, in that order.
If you shut off your skimmer for a day or two there is usually no problem. I have also shut off all my lights for four days to kill algae and again there was no issue with the corals. But I have had…
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