i battled with cyano
for a couple of months. here's my 2 cents worth...
1. be careful with chemicals - they can never work out exactly what is bad and what is good so some good is likely to be removed from your tank. i dosed "anti-red" to try and kill it and it failed. my corals (esp. pulsing xenia) shutdown. it also says to move fish out of your tank should any look stressed - easier said than done in most cases. from experience, IMO
I would dose at 75% of the recommended dose on the packet.
is often (but not always) due to high nutrients. cyano
is always in your tank, it only "pops up" when it manages to either overpower the "good" bacteria or there are enough nutrients to feed both happily.
3. physically remove as much as possible first (that is what the instructions will say on the chemiclean anyway). there is no easy solution. you have to continuously syphon it out - it is tedious, annoying and time consuming but there is no real easy way. before each water change, make sure you suck as much red out as possible (the red is not the actual bacteria, its what they exude) thats why i recommend a scrub with a toothbrush to fully "loosen" it. you can almost "peel" the red off the sandbed!
4. i researched cyano
for weeks (as i was battling it) this is by far the best article i found. i highly recommend having a read: http://netclub.athiel.com/cyano/cyanos2.htm
5. finally and most importantly, deal with the cause not the effect - fix ya skimmer and keep up good and regular maintenance!