Nitrates and lights are sources of energy for the algae. Phosphates are used to build the algae. Frequent and consistent water changes, a good skimmer, refugium, and good natural bacteria can help keep the nitrates down . A photo period of 7-8 hours, quality bulbs that are not past the 7-12 month range or high quality LEDs in proper spectrums and the correct intensity will solve most lighting issues. Phosphates are usually introduced to the aquarium through fish foods. Overfeeding is the #1 reason aquarist have nitrates that are too high. Reducing the amount you feed and using quality foods will help, also making sure you fish are eating most of the food. Turn your pumps off and feed slowly with a turkey baster. This not only helps insure that your fish are actually getting most of you food but will also help you feed fish that do not get to the food as fast ( an example being a Mandarin Goby). Feeding this way also allows you to target feed coral the soupy part of the thawed frozen food and gives you another great way to interact with your reef. The best thing you can do to combat algae is put some phosphate remover or GFO in a media sock and put in a high flow section of your biocube's filter. Be sure that you don't stuff the sock too tight, water has to flow through it in order for the GFO to work. Hair algea and other types of invasive algaes have a real hard time surviving in an environment with phosphates below .03 ppm. Algea uses phosphates to bind and build so without phosphates the algae weakens and eventually dies. Phosphates also inhibit coral and coralline algae growth as well as weaken coral skeletons, so it is very important to keep phosphate levels below .03 ppm. Most test kits have a hard time with giving accurate phosphate readings. I use a Hanna Checker, they are pricey but worth it IMO. To remove the algae, go to Harbor Frieght and buy and mini car cleaning vacumn kit for 7.99 and about 8-10 ' of 1/2" inside diameter vinyl tubing. The mini vacumn keep comes with an end with soft bristols on it you can attach to the vinyl tubing . This allows you to scub the hair algae and have it be siphoned out of the water at the same time. Also keep you DKH around 8-10, calcium 400-440 ppm, and magnesium close to 1300. I have noticed in my aquariums a correlation between low alk and low cal and small algae blooms also. The last thing is good water flow. Dead spots in the aquarium can allow detritus and other waste to build up giving algea another foothold. Jabeo RW4 ( 50 bucks on eBay) is an affordable powerhead that allows you to adjust the intensity and pattern. One of those properly adjusted and on a pulse or reversing pattern would be great on preventing dead spots and your corals will love it. Sorry so long and forgive typos but I hope it helps!
