Hair algae is the scourge of the marine aquarium world. Not only unsightly, it can devastate a reef tank by choking out every light-loving thing in its path. Use these tips to prevent or eliminate a hair algae problem in your aquarium.
1. Watch Your Feeding
Feed smaller amounts of food more often (2 to 3 times a day) to keep food waste from building up in your tank. To prevent food from being sucked up the filter, turn off your power head and filter pump while your fish eat. Make sure everything is eaten by staying and watching. A lot of food going to waste? Feed less and less each feeding until your fish eat all offered food.
2. Monitor Your Protein Skimmer
Make sure your protein skimmer is working properly. Skimmers peel off organic waste before it breaks down into nitrates (think of it as algae fertilizer); The better it works, the less nutrients available for algae in your water.
3. Make Frequent Water Changes
You should be replacing 20% of your water at least once a week (up to a maximum of 3 times a week). Make sure to use a gravel vacuum to siphon extra food and fish waste from the gravel. This process is crucial for reducing nitrates and phosphates that feed algal growth.
Tip: After sucking up the waste, take the large vacuum end off of your siphon hose and use the end of the hose to pinch the algae off the rock. This manually reduces algae and algal particles that can reattach elsewhere.
4. Lower Nitrates and Phosphates
Even if water testing does not indicate high levels of these nutrients, the presence of hair algae is a marker for significant amounts of nitrates and phosphates (or both). The algae wouldn't be out of control without it; it is just being consumed as fast as it is being produced. Products such as Prodibio Bio-Digest, Tailored Aquatics Nitrate Destroyer and Phosphate Destroyer, Seachem's Phosguard and Denitrate are helpful in competing against algae for these nutrients.
5. Reduce Lighting
Reduce your aquarium daytime lighting to 8-10 hours. This shortens the photosynthetic period and slows down growth until the algae is under control.
6. Stock Cleaner Inverts
Get critters that eat hair algae in your system and get enough of them. 1-2 snails and/or hermit crabs per gallon is minimum for a serious hair algae problem. Adding other algae eaters such as lawnmower blennies, sea hares ( a large algae eating nudibranch), and multicolour or short spine sea urchins will also speed up the process. See cleaner package suggestions for various sized aquariums.