Green hair alge

Question
I have been involved in coral reef tanks for over 15 years, I also have a good working knowledge of tank chemistry due to my back ground. I having a big problem with excessive hair algae growth. I have never had a problem like this and also the pet store I deal with is having the same trouble. I use RO water and all water chemistry is ok. I use LED lighting and a UV canister filter. I have been told its from organic matter being added to the system. I ruled this out by feeding restrictions and also of importance is my tank is 75 gallons with only 4 fish. Being told algae can only grow if nutrients are present is hard for me to belive for I know algae have cloropplast that turn light into simple sugars. I also read that very low levels of phosphates can also be the problem. Any suggestions
RJ

Answer
I believe some of the elevated growth of hair algae that a lot of us are seeing around the country, is due to a rise in pollutants found in almost all waterways. Even though most hobbyists use filtered reverse osmosis water, some of these micron contaminants, including dissolved nutrients and phosphates, as well as other pollutants like resins from prescription medications still find their way into aquariums, via the water we use when doing water changes, or when topping the aquarium off. In reference to resins from prescription medications being found it certain waterways, this is caused from a rise in prescription medication usage that Americans are taking abroad; the contaminants are introduced where old and ill maintained faulty underground sewer system infrastructures leach water into other waterways, including pipe lines to reservoirs where water is treated for home drinking water.

A couple suggestions include:

If your aquarium light is scheduled to run 12 to 14 hours, cut it back to 8 hours. Hair algae takes nutrients from the water to use as fuel, however as you know it also needs a steady amount of light for food conversion...

If you don't already have a herbivorous clean up crew, consisting of large snails and hermit crabs, I'd suggest adding some.

If you suspect your feeding regimen of being part of the problem; change brand fish foods, look for brands low in artificial additives.

A good filter media to help keep phosphate levels down is Seachem Seagel, add this to your filter. See the link below as an example. It can also be found at your local fish store.

http://www.ocreef.com/seachem_seagel_250_ml

I wish you luck with all your future saltwater aquarium endeavors.

Sincerely,
David