I have mainly LPS, anemone and soft corals, I am not sure about the clam or SPS. But turning the light off for 3-4 days was the most effective way for
me, without using chemicals, to control Cyno. I have done it few times without losing any corals.
Foxface and 2 bar fish and 4 tuxedo urchins eliminated the bubble and hair algae
A good person to reach out to is Richard Ross, last year speaker, who encouraged me to use the light method.