Getting tired: cyan/algae issues

[Amatuer21]

My tank has been up and running just over a year now. Ive been struggling with cyano and gha (only on back wall). Ive place my mp-10 in every position possible and am convinced now that flow is not the issue that is causing the cyano. Its a small 20 gallon aio style tank. I run chemi-pure elite and just added gfo into a media bag and placed into the back chamber of my media rack. Before i placed the gfo into a media bag, i ran it through a small reactor for nearly 3 weeks and did not see any improvements. But, i had to remove my skimmer due to not having enough space to run both at a time. Since i seen no improvements, i just took out the reactor and put my skimmer back in. I test p04 with a hanna checker and always get 0ppm. Currently out of regiments so i can't test for that at the moment but what else should i be testing for? Also, i run a 150w mh over this for 6 hours a day, been running the same photo period for atleast 10 months. Could it be to much light? I perform atleast a 4 gallon water change once every week or so (usually never go 2 weeks without a change) and remove as much cyano, gha as possible but as always it comes right back. Salinity 1.024-1.025 as always. Any ideas of what i can do or should do?

[Yellow Eyes]

Check out this post from Sk8r: http://reefcentral.com/forums/showthread.php?t=2454334&highlight=cyano

Basically turn your lights off for 3 days, blue on the 4th, back to normal on the 5th; repeat for 3 months. Run your skimmer to skim heavy, and it should help.

I just finished month #2 and the cyano, what is left and which is noticeably defeated, comes right out during the water change (which I perform on the blue light day).

It does come back, but hopefully after month 3 it will be less. I also don't run any GFO, just some Chaeto in the fuge.

[bertoni]

Better skimming might help, and carbon dosing is another possibility. Often, adjusting the feeding level can do a lot, too.