u gotta try my trick if u want it gone. I battled cyano
also and it wasnt due to a lack a maintenance like most sites tell u. I just simply over fed had a coralife skimmer like u and didn't know what I was doing.
Blast ur rocks and tank a airline tube to such up the cyano
on the bed and get in every crevice. If u take a hard Line tube about 6 inches and attach it to the end of the soft tube it will make things easier.
Take to water u sucked out and filter it and put it in. There is cyano
in it so it won't have nutrients. Maybe little at thus point but nothing else is working and eventually it will be nutrient free
Keep the lights out for about three days. Ur corals are going to not like it but the blackout will help slow the growth. While u blast and filter
Every two days from when u turned off ur lights keep pulling out water and filtering it and putting it back. That way u don't use any salt and u are also slowly lossing the nutrients in ur tank. Some nutrients may be getting by on that filter ur using there is just no way to tell. I don't trust any water but the water I make. For the time being I would top off with distilled water as well except test the supply u buy for copper as some companies store it in huge copper tanks.
Do this along with the other usual suspects such as increased skimming and turnjng off the flow when u feed to decrease the chance of lost food.
Stop using the chemically pure I used it also but everytime u use it the co2
in ur tank increases and this also fuels the cyano
. The only thing that red slime chemipure does is oxidize the cyano
skeletons but doesn't get rid of nutrients and the root cause. Give it a shot it worked for me and other peolple I know.