Cyano is often a case of too many nutrients and too little flow. Have you added another powerhead? It will help with the
cyano and your corals will appreciate the increased flow too. I've ordered a few of these
The Best Nano Pumps, 250gph++, Gate Valve, 3-6w Power Supply - $4.99 : Fraggle Reef, Premium Corals and More but haven't had time to install them yet. I'll get it done next week (before the inlaws get here for my hubby's 50th b-day.)
I agree with Pearson regarding the addition of new fish while ich is present in your tank. The parasite has a 4 stage life-cycle and only one stage is on the fish. This is why you see it come and go.
In my experience the shrimps are a little sensitive. If you had a lot of evaporation and topped off the tank you could have changed the SpG quickly enough to have
