Hair Algae Overview
Welcome to Derbesia sp, or its more popular names, Hair Algae and Green Hair Algae. This is a guide on how to eradicate these pests from the marine aquarium.
Along with Red Algae (Red slime algae), brown algae (Diatoms), everybody in the marine aquarium hobby has had to deal with these pests at some point. And i mean everyone. At first it's a few small clumps here and there but before you know it, its everywhere. On the live rock, substrate, power heads, glass and on even on your precious corals.
For those that struggle with hair algae in their tanks, these things can be a complete nightmare. You pull them out, but they just keep coming back like the Terminator or something. Algae control takes precedence over everything else in the tank. Thankfully, there are ways of getting rid of hair algae that will work all of the time. All it takes is a bit of effort and patience. So lets begin.
Tank full of Green Hair Algae
Hair Algae : Nutrients
Nutrients. The key to fighting hair algae is nutrient control. They are spreading throughout your tanks like wildfire because there's an abundant amount of food for them to consume. Not to mention the fact that they are photosynthetic and your tank probably has a lighting system in place. So the first thing you want to do is manually remove as much hair algae from your tank as possible. Then, we'll tackle nutrients.
The nutrients we are concerned with are Nitrates and Phosphates. Where do they come from? If you remember the bacteria cycle, you know that we eventually end up with nitrates. Most tanks aren't built to convert nitrates to free nitrogen. Some tanks do this very well like those with deep sand beds. If you have a hair algae problem i'm going to assume that your tank probably doesn't convert nitrates to free nitrogen too well.
Fish food and fish waste are the two things that introduce nitrates (becomes nitrates eventually) and phosphates. So the first step towards nutrient control is to clean your entire tank. Take out your pumps, protein skimmer and every other mechanical item you have in your tank and clean them all. Remove as much uneaten food, fish waste and detritus from your tank as possible. While battling green hair algae it is important that you lower your feedings. Fish food and fish waste contribute greatly to phosphates and nitrates.
We look for other sources of nitrates and phosphates next. Your water. What kind of water are you using? RO/DI water or treated tap water? Tap water contains both nitrates and phosphates in varying amounts and every time you put in top off water or newly mixed saltwater you are introducing nitrates and phophates in to your system. The solution here is simple. Stop using tap water and start using RO/DI water.
The best way to quickly remove nitrates from any system is to do frequent water changes. For phosphates, get a phosphate remover and put in an area of high flow. If you have a mechanical filter with a compartment, that will do just fine. There are many brands of phosphate removers on the market and they are all either aluminum or iron based. Some hobbyists have had issues with aluminum based removers (Affects their corals) and tend to stick with those that are iron based. Personally i've used both iron and aluminum based phosphate removers with no problems.
Green Emerald Crab
Hair Algae : Creatures That Eat It
There are also some invertebrates you can get that eat hair algae. Nerite snails, turbo snails and green emerald crabs are all well suited to the task.
Another cause for a hair algae outbreak may be your lighting. If the bulbs are old, they may change spectrum. Hair algae really thrives in the red spectrum so changing your bulbs is a good idea as well.
If you want to quicken the process you can opt for a hair algae removal product. Do they work? Yes. Once the hair algae is gone will it stay that way? No. Because you're not addressing the root problem of how your tank got green hair algae in the first place.
And that brings us back to Nutrient control all over again. As i mentioned above, this is a slow process that will take weeks. But with perseverance you will nip this problem in the bud if you follow my suggestions.
QUESTIONS OR COMMENTS? PLEASE LEAVE THEM IN THE BOX BELOW.
grady white on January 08, 2011:
sea hare works spelled wrong sorry. My tank is 20 years old. I have an ETS skimmer,and a 40gal sump.
grady white on January 08, 2011:
Try a sea hair. Worked in my tank mowed all hair algae down. I use 14000k metal and rho lights on my 125 gal. reef tank.
PirateFX (author) on October 16, 2010:
Hi Randy, sorry to hear of your troubles. Red slime and hair algae went wild immediately after the bulb change? Everything points to the new bulbs being the culprit. But i personally know reefers that use 10k bulbs with no problems. Certainly perplexing.
Could you check what your nitrate and phosphate levels are? Is this a reef tank (corals + fish)?
randy Harper on October 15, 2010:
I have a 11 year old 125 gallon tank with a 30 gallon sump full of calupa. I run two protein skimmers in the sump. Hair and red slim after i changed my lights have gone out of control. i did switch my two metal halides to 14 k from 10 k. I kept my six compacts light at 4 at 10 k and 2 actinic. i feed my six fish one cube of frozen about 5 out of 7 days. I have not done testing of water for years because of the balance of the system. I have around 200 lbs of live rock above and 50 lbs below.
do you think the 14 k lights made the difference.