cyano outbreak

[ROCHESTER REEFER]

happy easter everyone, i've got a 120 rr which has been set up for about 4 months. at first i will admit i overfed but have cut down now for 2 weeks and the problem seems as bad. parameters are good 5ppm nitrate, 8.2alk,385 cal about 1200 mag.no phosphate. i recently read a post on rc which spoke about sunlight. i keep shades drawn to block direct sunlight, but i have an entry door facing the am sun which has an oval kinda decorative glass in it with bevels and i noticed (after reading that post) that some of those glass pieces reflected light directly at the tank. i've got that oval covered now but that article says lights out for 3-4 days so my ? is weather or not to do it. i have a handfull sps in there which seem very happy along with the fish. thanx in advance for your help.......walt

 

[pdd]

Four months is not that a mature tank. You do have Nitrates and yes you do likely have phosphaste. Most test kits will not detect the that will still cause issue sin a sw tank. Two weeks is not very long to expect the problem go away after over feeding by itself. Water changes will help the nutirients cyano is using to grow. I am guessing as the nitrates go down so will the Cyano. How much flow is in the tank? The cyano will usually not grow in areas of moderate to high flow. Moving powerheads it increase flow over problem ares will sometimes help, but it will not replace the need to export the NO3/PO4 from the tank. What is your bioload? If it is heavy with a young tank it may be hard to get the NO3 to near zero.