steve8855

can you give us a little more input? what are your water parameters? what type of algae? how fast is it growing? it is normal to have to fight with certain types of algae anyway so depending on the type we will know a little more but to answer your initial question I would say yes you are running your lights too long. 13 hours is a bit of overkill for me but everyone has a little different opinion, what I did with mine was run them slowly higher or lower in hours taking it up or down about 30 minutes at a time over a few weeks to get where I felt was a happy medium, most people run their lights anywhere between 8-10 hours a day I sit at about 9 myself.

I agree with cyano, we need some more info before we can give proper advice

one thing to take into consideration is how often you do a water change, you may read low nitrates or phosphates due to the algae consuming it all

I run my lights 12 hours a day 1 hour 330watts of blue next hour I add 330watts of tri band next 8 hours I add in the 3 250 14k mh than reverse to shut down and dont have any algae trouble and only have 10 hermits and 4 Mexican turbos for the cuc in a 180. I would say either water or the light spectrum of the leds. I have a marineland led on my 72 bow African tank and it grows mad algae red and green

13 hours is much too long. 9 hours maximum. Most photosynthetic stuff stops production in 5-6 hours time, if I recall correctly. After that, the excessive lighting can actually exhaust coral growth. Algae grows at lesser wave-lengths which is why it is thriving in what would be poor conditions. Occasionally people post about how they traveled on vacation and their lights never shut off resulting in a massive algae outbreak and coral losses because the lights ran for days and days.

I dint know that Marc I should probably start cutting mine back some. I learn something everyday, us hillbillys are always out of the loop Would defiantly help on my electric bill

algaes do absorb the light but they use that energy for growth and reproduction when its dark. one half of photosynthesis occurs when the lights are on, the other half occurs when the lights are off. when algae is constantly exposed to light it will act unnaturally and go wild... its important to have a dark period to regulate how the algae will behave. i suggest you dont make any fast, drastic changes, go slow...