Need help with cyano..

[Mbbenz89]

Hey all , I have a small 40g tank up and running a year and a bit but a 150 came up so I grabbed it as well and it’s been running 6 months. This passes month cyano has shown up and I’ve never dealt with it before.. I used Chemiclean and it almost went away then a few days later back in full force… no idea what’s going on I have a refugium with cheato and mangroves, a carbon and gfo reactor, a 25w uvsterilizer and I still can’t figure out what’s wrong.. it seems to be killing all my hermits and snails fish and corals seem ok but just wondering if anyone else has similar expirence that can maybe help me figure out where I’m going wrong.. current numbers are phos 0.12 nitrates 17.1 calcium 508 mag 1305 ph8 alk 8.8 all done with Hanna testers this morning. Any help figuring out cause would be greatly appreciated

I do a 10 or 15 gallon water change every 10-12 days and I can’t really turn lights off as I have a few corals that I don’t want to lose

 

[MnFish1]

This is going to be slammed - I Know - but Chemiclean. It will take care of the cyano - should not do any other harm - and then water changes, etc. It's impossible to know exactly what to recommend - as there are many chemicals that an ICP test will not reveal that may influence cyano. Thats my recommendation - and I rarely recommend chemicals

 

[PokeFish]

try upping flow and siphoning as much out as u can during water changes

 

[Mbbenz89]

try upping flow and siphoning as much out as u can during water changes

I added 2 Neptune wavs maybe just need better placement and I try to vacuum as much as I can, I also just changed my filters on the rodi system I have so I don’t think it’s anything to do with that as my small tank has used same system and never had cyano