imo, a better soloution, would have been to advise you to do a very substantial cleaning of your system to remove excess nutrients in the forms of detritus, and to physically remove as much of the cyano as possible, ie, taking each rock out and rinsing or scrubbing it if nessesary, and siphoning/cleaning the sand of any detritus/algae. also cleaning your sump if there is any excess algae/detritus there as well.
u should do it all in one water change, but i would leave half of the liverock in the tank while cleaning/replacing the other half so your tang has somewhere to hide and doesnt spazz out too bad.
after this, then treat with the oxidizer(what chemi-clean is). as far as the skimmer going nuts, kinda unavoidable until the oxidizer diminishes some...
set your skimmer on it's lowest setting and let it take it out...if you have a drain, you can use a bucket, and have a pre-made bucket of saltwater on hand to replace the water. extra carbon changed out every 48 hrs will help too.
then figure out what you can add to the system to control the excess nutrients that arent being handled...
maybe increasing your flow in the display, adding a refugium, or a bigger refugium, a better skimmer, a media reactor for your carbon and phosphate medias, and a media reactor for biopellets.
also, imo, lighting has nothing to do with it. it's all water chemistry. look at how much light energy is in the ocean, is it covered in cyano??
