Mine are on the sand bed under the stock rsm lights (110 watts, 50% 10k, 50% blue), and a 12 watt blue stunner strip. They had been doing great under that configuration.
Water changes are 10% per week. I have not had any big fluctuations in any parameter. The values I posted last month are par for the course.
Equipment wise I did get a new skimmer and power head earlier this year. I'll explore the stray voltage theory. Though, the other corals look good.
The only big change that happened this year is my victory over cyano. Since it has been gone the zoas have been growing great.
steve