Got Hair? Hair Algae I mean.. how to keep it out of your tank and How to get RID of it!

Hair Algae on rock

Got Hair?  Hair Algae I mean..  how to keep it out of your tank and How to get RID of it!


Hair algae is a light green or green-gray type of algae that can become a nuisance in the aquarium. In a favorable environment, hair algae can grow really fast and an aquarium can therefore become filled with long, green “hairs” in no time. Even after a good manual scrub, the algae can be back within a few hours.

Hair algae are capable of growing attached to most types of surfaces, from stones and aquarium decorations to glass, equipment and plants. Hair algae might look unsightly in the eyes of the aquarist, but it has its own role to play in the ecosystem and quite a few organisms like to feed on hair algae. In the limited space that is an aquarium and with too few natural enemies and too few plants and other types of algae to compete with for light and nutrients, the hair algae can however become a problem not only for the aquarist but for the inhabitants as well.

The predominant nutrients that cause most of any algae issues are phosphate and nitrate. Go test your tank. Is phosphate reading zero? Nitrate probably is too...or at least very close. I bet they are! That's because you can only test the water column, and that dang HA is feeding off of it, and sucking it out of the water column so your test kits can't test for it. So don't be fooled!  The biggest reason for hair algae growth is poor water management.

Now, first thing first. Mow that HA down!!! Turn off all the pumps in your tank, get out your siphon hose (use just the hose not gravel vac end), get out your scissors, and give the HA the shortest brush cut you can, and be sure to suck all the loose bits out too, eh? If you simply kill the HA, and it dies in the tank it will release the phosphate it has been eating right back into your tank...and voila! More HA. You can safely to do a 50% water change if you have enough water on hand and you end up taking that much out while you're trimming the algae. While doing water changes use your siphon hose to get into all the nooks and crannies of your rock to suck out as much detritus as possible. Suck out any detritus that has settled on the sand bed as well without disturbing the sand bed and its beneficial bacteria.

Use a turkey baster to blow the detritus off your rocks once or twice a day while you're battling HA. If you have so much HA that you aren't done brush cutting it by the time you've sucked out 50% of the water, then fill the tank back up, and carry on again in a day or two. Make sure you aerate the fresh saltwater for 24 hours before you use it and always match temperature and salinity during water changes, especially large ones.

Keep up on regular weekly water changes (10-25%). Give that HA a good brush cut every time you do a water change, and suck out all the detritus from the rocks and on the sand. If you're repetitively finding lots of detritus you need to rearrange your power heads, replace them with bigger power heads, or add another power head. Half the point of power heads if to keep the detritus from settling. Your filter/skimmer can't get the detritus if it's settled on your rocks or sand bed. Make sure there are no dead spots in your circulation for detritus to settle.

Blue Dot Sea Hare LOVES to eat Hair Algae!

If you want to use algae eaters to control the algae, make sure that you pick suitable species. To begin with, the species must be suitable for your particular aquarium. Many algae eaters are forced to live in aquariums with an unsuitable pH-level, temperature, tank mates and so on, because the aquarist is only interested in their algae eating ability and does not care about the fishes/invertebrates and their well being. Secondly, get algae eaters that love to eat hair algae. Many algae eating species are not very fond of hair algae and some might even decide to devour you live plants and leave the hair algae alone. Last but not least, most algae eating species prefer young and fresh algae, so you should be prepared to remove the old hair algae manually. 

Oh...you're making fresh saltwater? Where are you getting your water from? The tap? Yikes (but not a huge No No depending what is in your tap water)! Could be full of phosphate! The grocery store or water store? Check their inline TDS meter before buying, and be sure it is at least 5 ppm or less. Test your source water for phosphate and nitrate. If you're already buying from the grocery store, then you need to look at buying an RO unit. By the way, 1 ppm of phosphate is A LOT for a reef tank.

The best option for a reef tank is to use a 4 stage (or better) RO/DI unit. When buying a RO/DI system buy a hand held or inline digital TDS meter and calibration fluid at the same time. Buy sodium chloride or potassium chloride calibration fluid that is similar to the TDS of your tap water ie 342 ppm. Distilled water is not suitable as calibration fluid. Use your TDS meter every time you use the RO/DI system. Your TDS should be zero. Not 1 ppm, not 2 ppm. ZERO. The first time it pops up to 1 you need to replace some cartridges, but that's a different subject!

Buying an RO/DI not feasible? Save your pennies...in my opinion, not having an RO/DI unit is like not putting salt into your reef. It just doesn't work too well. Shop around, you can usually find them for $150-200, or keep your eye open for a used system for $100 or so! I found one on Craigslist for a STEAL!  Just remember you may need to replace all the membranes ($$$) when you buy a used one, so a good deal can be not so good real quick!

What's the calcium, alkalinity, and magnesium at in your reef? Calcium should be 380-440 ppm, alkalinity 7-12 dKH, magnesium ~1350 ppm. These numbers are for 1.024-6 specific gravity. Low or unstable alkalinity encourages algae growth, as does low magnesium. And Calcium? Without calcium your corals and decorative coralline algae won't grow very well. Coralline algae helps to prevent nuisance algae growths. Be sure to test your water change water before you add it to the tank and add calcium, alkalinity, and magnesium if it needs it. Test your water change water at the proper salinity too, eh?

Ok, I think we have the water figured out. Now, what are YOU unintentionally doing to compromise the success of your reef? Is your tank overstocked? Most peoples' tanks are. Oh, and you're probably overfeeding. Or using poor feeding methods. Every time you feed your fish you are adding phosphate to your tank, so you want to minimize this as much as possible obviously! Cut your feeding back to HALF the amount, but be sure to feed once a day, no less, no more. Fish need to be fed everyday, their digestive systems are too small to get fed less, but cut down the amount you're giving them by half. They won't notice.

When you feed, don't just dump it all in and walk away. Add a little bit, then a bit more as they eat up the first bit. Make sure you never dump enough in there that it hits the sand. It should never hit the sand. If it does you're feeding too much. Have a Jawfish or Goby that doesn't come up for feedings? Use a turkey baster or some such thing to get the food directly down to him. He'll get used to it, but try not to show the other fish what you're doing with that turkey baster because they're a pain in the butt if they start following it down.

When you feed frozen food, all that juice is like a phosphate drink! Thaw frozen food in a little cup with RO water or tank water (not tap water). Once it has thawed pour the water down the drain before feeding. You don't want that thawed food juice in your tank. I use a tea strainer, works like a charm and cheap too.

So you have heard about those TLF PhosBan reactors I bet? Go get one. Period. You'll thank me later. Now, you gotta be careful. If you suck too much phosphate out too quickly you will shock your corals, and they just may bleach on you. So, get yourself some good phosphate removing media (Bulk Reef Supply HC GFO, RowaPhos, etc)...be sure to get a media that is reddish brown, NOT white. The reddish brown stuff is often referred to as GFO (granular ferric oxide).

We're gonna be safe and assume there is a lot of phosphate in your water, so add about 1 mL GFO per gallon of water in your reef. In 3 weeks add another 1 mL/gal to the existing media. In another 3 weeks (6 weeks total) dispose of all the old media. Refill with 2 mL of fresh GFO per gallon and let it run for 6 weeks. Dispose of old GFO and refill with 3 mL GFO per gallon and let that run for 6 weeks. Usually 3 mL GFO per gallon is a good maintenance amount, but some people use significantly more. You will learn when you have to change it out because you will start to see some algae growing usually on the front glass is the first sign, and adjust the amount of GFO you use so that you can change it every 4-6 weeks.

Be sure to rinse all new GFO in RO/DI water until it runs clear. Alternatively, you can put it in the reactor without rinsing and catch the first gallon or so of dirty water that comes out when you plug it in. Don't let that dirty water get into your reef! GFO in reator = good, GFO in tank = bad. Adjust the reactor so that the very top bit of the GFO is "boiling" very gently, just a bit of movement. The more contact time the better it works.

Ok, so maybe you have a big refugium? Well, get off your butt, and fill that fuge with chaeto instead of rubble and sand! Bare bottom is fine or a little bit of both.  Use a powerhead to make the chaeto roll in the water. The chaeto needs to roll freely for best results. Trim it when it gets too snug to roll. Light the crap out of it (try some clip on lamps with household spiral compact fluorescent bulbs around 55-6500K), and pray to your god for that chaeto to absorb all the phosphate from your water!!! .

Now...those lights of yours. When's the last time you changed the bulbs? As a bulb ages the color spectrum changes. It goes from a bluer color to a redder color. Algae LOVES red. So, replace MH bulbs every 12 months, T5 8-12 months, VHO 12 months, PC 6 months. If you're running low Kelvin bulbs like 6500K or 10,000K try using bluer bulbs like 13,000-20,000K. The length of photoperiod doesn't affect HA very much, so don't worry about that too much, but typically your main lighting (MH or the full T5 fixture) will run for 6-8 hours per day with supplemental lighting (blues or actinics) running 12-14 hours per day.  I am personally a huge fan of LED lights.  They are by far better than anything I have used and depending on what you have in your tank better than Metal Halides.  I have a 3 part post coming soon on LED lights...

To help this battle along I've got another idea. Boiling water. The age old friend. I mean who doesn't like some nice hot water? HA doesn't! Get that water boiling strong, grab a syringe, suck some boiling water up, run to your tank quickly, and spray a good jet of boiling water right in the midst of your HA. Be careful not to spray any of your corals...they don't like boiling water either. Don't use a turkey baster because the water will spray back out (will do that with some syringes too so be careful!). To be successful you HAVE to get that boiling water right in the forest of HA QUICKLY. Oh, and be sure to siphon all the dead crap out the next day. Better yet, give your HA a brush cut before you boiling water it.

Ok, you've tried everything...it's been a few months, and you're still brush cutting that HA. Now it's time for the big guns. If you have the Bryopsis type of HA (it's feathery unlike Derbesia which is grassy or like a green cotton ball), then this will work. If you have Derbesia, this won't work. Get yourself some Kent brand liquid magnesium. The Kent brand works best. It's cheap, don't worry. Pump up your magnesium to 1600 ppm. Don't worry it won't hurt the critters or the corals (not in my experience anyway, but I take no blame for you trying this...do at your own risk!!). Pump it up by no more than 100 ppm in a 24 hour period. You see...HA doesn't like magnesium to be all high like that n stuff. So, this could help you out. Once the HA goes away, just quit dosing it, and carry on with your regular water changes. The magnesium will slowly drop back down to where it should be.

A more advanced approach to algae control is to use a nutrient reduction system like ZEOvit, Fauna Marin, Prodibio, etc. If you decide to use these systems, according to the manufacturers you should not use GFO. Zeovit suggests you can use Coral Snow and ZEObak on their own to help with cyano outbreaks, but according to CanReefers this method isn't very effective. You would have better results using the full nutrient reduction systems.

A new product on the market is BioPellets available in several different brands. I have personally used these, and I have read many mixed reviews. I'm not sold on this product yet, but await to see what future reviews it will get.  I mix biopellets and some carbon for clearer water column and interchange this mixture with the phosban in my phosban reactor. 

If it's persistent after all this, then maybe you need to consider "cooking" your live rock (see link below). It is definitely possible that your live rock is leaching phosphate and/or nitrate from die off at some point in its life, and the easiest way to battle that is to remove it all and cook it. This is extreme - last resort sort of thing though. Btw, cooking does not involve the stove!