Those are definitely signs of acro corals being starved. Corals need more than just NO3, PO4 and light. They need bacteria. Fish poop is a great way to keep bacteria cycling in the tank. Since you can’t have fish for a while I would at least try to add a lot of snails and other inverts that can help make bacteria as well as increase your nutrients. In all honesty, it is extremely difficult to maintain an SPS system without fish. The fish provide a great source of nutrient import. Hope this helps…