algea still

Question
We followed your advise about getting turbo snails to take care of the green fuzzy algea and they have done the trick however we're still having green algea on the sides and front of my 29 gal. tank.  I don't believe we're feeding the fishes too much and all chem. testing appears good.  The only difference we can think of is we have increased the light time --- maybe we increased the on time too much?  I'm affraid we may be crashing the tank because of the algea.  What do you think?

Answer
Hi terry. Green algae in a tank is not a horrible thing. It won't cause problems unless it gets so out of control that it smothers corals or starts messing with the water chemistry. The only reason most people do not like it in their tank is because it is ugly! It won't cause your tank to crash and can actually improve water quality. Some people employ the use of a refugium filter which houses and grows all sorts of hair algae as well as other algae. The water from the tank is then filtered through the refugium where the algae takes up all the left over waste products in order to improve the quality of the water. If you start to get red slime algae then it may be a cause for concern but the reality is if you didn't have any algae in your tank then most likely your water chemistry might be testing worse. Algae is also a food source for some snails, crabs, shrimps,fish and a whole variety of planktonic organisms, most of which are extremely beneficial to your tank. Look at it this way; if there were no algae in the ocean there would be no other life as well! The trick is not to have your tank completely algae free but to strike a balance between the algae, the nutrients it takes up and the organisms which eat it. If it is growing out of control then you may not have enough algae eating organisms or you may not be doing frequent enough maintenance for your tank. All tanks are different and the cleaning schedule that works for one may not work for another. I don't remember if you have any corals or other light needing invertebrates in your tank but if you do then cutting back the light may not be a good idea. If you don't then cutting back the amount of time the light is on will help a little. The only problem that too much algae can cause is a large fluctuation in pH. During the day the algae takes up CO2 from the water and releases oxygen. Water with a lower CO2 content tends to have a higher pH. During the period of darkness the algae then takes up oxygen and releases CO2. Water with a higher CO2 concentration has a lower pH. With too much algae in the tank the pH can become dangerously low during the hours of darkness and extremely high during the daylight hours. This fluctuation can have an adverse effect on the inhabitants of your tank if it is extreme. Test your water first thing in the morning after the lights turn on and at night before they are turned off. If there is no difference in pH then your are okay. If there is a slight difference that is okay as well. If it is a large fluctuation then simply hand pick and clean whatever algae you can and see if there is an improvement the next day. Another trick to help control the algae that grows on the glass is to use high quality paper towels and toss them after each wipe trying to capture as much algae as you can in the towel and not let it escape back into the water column. You can also use a sponge made for cleaning tanks and rinse it off between swipes. I have found that the paper towel is a little less messy and a little better at capturing and holding the algae then some of the sponges made for cleaning the tank. Don't worry too much. Just keep up on the cleaning and your tank will be fine!