good ol' cyano Q's

[burrows14]

so I'm fighting some pretty bad cyano on the 120g. I just used a scraper and a net and pretty much took off the top layer of my subtrate. i plan on cutting my mh lights for the next couple of days and wondering if its ok to run my actinics or should i do a total black out. ive also cut my feeding down but also wondering if there is anything else i should do? i dont want to add any chemicals unless its a last resort. just checked my levels and they all are perfect but the cyano is prolly effecting the tests.i was thinking of running my phosban reactor but 1 of the orings is toast so thats out of the question. I am open to sugestions if anyone has any!

cheers
Ray