By Bob Goemans
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Bob Goemans corresponds with Fred and Amanda

Fred and Amanda writes...

Hi Bob,

We have had a bad algae problem for about three years! We were told it was hair algae but not sure and have attached a photo so you can see it. It looks like seaweed and is impossible to get rid of. We were told that it came from the brine shrimp we fed our fish and that it was in the water that they freeze the shrimp in, so now rinse all our shrimp first. All of our water tests come up ideal.

It's a 75 gallon reef tank and were told to get a sea hare to eat it, and we did, two large ones and two small Caribbean type. They did the trick. But before we did that, there weren't any corals remaining so we covered the tank and shut off the lights for about three weeks before the sea hares came. When they arrived we ended up with somebody else's coral and snails, a bonus. We turned the lights on and put all the new things in the tank. It took about two weeks for the sea hares to do their job and the coral were doing great. But the sea hares died shortly after they ate all the algae, which was about two years ago, but we still have the coral and it has even spawned a new one, which is also thriving.

We still have a blue damselfish and a cardinalfish that we have had for six years and also have a clownfish, which we have had for 4 years. There were two, but the other one died last year. These fish seem healthy and happy and we just wish we could see them better, as this algae is quite 'bad.' Six months after the sea hares died the algae was back and now we also have bubble algae all over our rock, which I'm sure doesn't help the filtering aspects of the rock. We are ready to give it all away, but I love my clownfish and the other fish have been around for so long they have become part of the family. We also have lots of feather dusters or fan worms that stick out of the rock, and were told this is good. We have read many books and been on many websites and find many people have different ideas of how to do things.

RO water is used, and we have about 200 pounds of live rock, use a protein skimmer, but it doesn't seem to be doing much right now. The pH is 8.2, NO2 is 0, NO3 is 0, NH3 is 0. Salinity is about 1.023 and we keep the tank at about 72F degrees. PLEASE Help!!!!!!


Fred and Amanda

Bob replies...

Dear Fred & Amanda,

Yes, that's 'hair algae' seen in your photo! Actually, the spores were probably brought in on corals or live rock and have now found a comfortable home in your aquarium and continue to thrive and multiply. As to any connection with brine shrimp, the only situation here with any relative connection is that overfeeding this foodstuff encourages its growth. Some simply goes to waste in the aquarium and quickly deteriorates producing 'ammonium,' which is the main 'food' for algae. And phosphate, which you do not mention, supplies the energy for their reproduction. Phosphate should be maintained at <0.015 mg/l.

Reducing light will not alone kill unwanted growths of algae, as most proliferate in dim situations because their nutrients/foodstuffs remain available. You may have a typo, as you say the tank temp is 72! That would be too low, as it should be more like 78 - 80F degrees.

And just because you have a NH3 reading of zero, it does 'not' mean ammonium is not present! It is, - yet not enough to be combined with 'ammonia' at your pH, to show up on the test kit. If 'ammonium' were zero, you would not have such a serious algae problem.

As for the hair algae, you may want to again enlist the aid of some sea hares as that will be the quickest way to rid the system of this pest alga. However, it will return, as various aquarium parameters will have to be surveyed and reworked. That will entail a lot of work on your part. If wanting to go this road, let me know and we will go from there.

As for bubble algae, breaking the bubbles while still in the aquarium allows hundreds of new spores/bubbles inside them to spread elsewhere in the aquarium. Reducing light will not help, as they grow in all places throughout the aquarium, whether that is in shaded or lit areas. The best approach is to try and wiggle them loose with your fingers and then remove - without breaking them. If attached to items in the aquarium where they can't easily be reached, it become necessary to remove that item and while out of the aquarium, removed those bubbles. Increasing water circulation, monitoring phosphate level, and cleaning the sand bed occasionally will help reduce their nutrient supply.

As for biological bubble algae predators, the Tangs in the Naso genus, the Sailfin Tang Zebrasoma veliferum, Rabbitfishes - genus Siganus, Urchins - Black Longspine Diadema setosum, and Tuxedo Urchin Mespilia globules and the Emerald Crab - Mithrax sculptus are said to consume them, however, not in great numbers. Actually, you're the best predator.

Hope this helps,


Fred and Amanda writes...

Hi Bob,

Yes, thank you as that does help a little, and no, our tank usually is only about 72 to 74 degrees. We keep our house at about 72 all year long even summer so the tank never gets that warm. Once while away the house got warmer and the tank got to about 80 and the algae got worse. The one coral we have seems to like it at 72 and we do have many button polyp corals on the live rock and they are doing fine. Should we really up the temp on the tank? What is the best way to test for phosphate? I don't overfeed our fish; in fact they probably would eat more often if I offered it. I feed them by squirting a little shrimp in the tank almost like feeding them by hand.

The first three years the tank was great! We had one Hawaiian Tang, two Yellow headed sleeper gobies, two emerald crabs, a few hermit crabs, a bunch of snails, and the damselfish and cardinalfish I mentioned before. We had a few soft corals and all did well. Our tang didn't eat much algae, as he became carnivorous. We were told they only eat plants but he refused to. Our gobies did a great job cleaning our sand, however they would drop sand all over the rocks. Then one day about three years ago one died, then about six months later the other one. Then our Tang died about a year after that. We think the algae started around the time the gobies died and the Tang only did a little bit of picking on it, so it got out of hand. The person who sold us our tank was great to work with and says all his stuff is top quality and that he has done some work for city aquariums and stuff like that, but I think he just wants our money. We now want advice we can trust, and that's why we contacted you!

As for the bubble algae, I am to blame. I have, out of frustration broken many, many bubbles. I didn't even think about them sending our spores when they break, duh! No wonder there is so many now. My thought 'now' is to remove each piece of live rock and remove the bubbles outside of the tank, rinse with saltwater and replace them back into the tank.

Would like to fix our tank, not just patch it!



Bob replies...

Hi Amanda,

As you may know, I've been in this hobby for over 60 years, but still don't have a magic wand so to speak; therefore, without a lot of work on your part, this problem isn't going to get a lot better.

Let me begin by saying the temperature for the creatures coming from tropical reefs near the equator is between 76 - 84 F with almost all marine hobbyists maintaining 78 - 82 degrees. Can some hardy species live at 72, yes, but not comfortably, nor should they subjected to temps they 'normally' do not incur in the wild. Does the lower temp slow hair grass growth - yes, but so does lower temps when it comes to the grass in your backyard. I guess you can see where I'm going with this, as my first suggestion would be to slowly increase aquarium temp over the coming week or two and bring it to within a 'normal' range for these 'tropical' species.

Before we enter into actual corrective measures (if you want to go there), there's some very good reasons why hair grass/unwanted algae flourish in aquariums - generally they are: their caretakers don't understand water chemistry; do not properly care for their sandbeds; feed inhabitants incorrectly/use improper foods; and, get bad advice.

Sandbeds of any depth should be vacuumed occasionally, usually once a month, as detritus continues to accumulate and the bacteria within does not consume all that enters for energy, therefore, animal waste continues to accumulate. And those that place a lot of live rock upon the sandbed make caring for this important biological asset, i.e., the sandbed, 'impossible' to properly accomplish. (Would people never dust their home?) Nutrients from dirty sandbeds enter the water and help spawn algae spores brought into the aquarium from other sources, e.g., corals and live rock. Furthermore, feeding frozen brine shrimp in anything except an occasional and careful manner is another source of 'energy' for unwanted algae. Then add to this 'algae' problem a lack of water chemistry knowledge, and one can see why the aquarium environment turns from a healthy looking environment to one that looks more like a polluted bay!

Can you turn things around in your aquarium? Yes, but it will take a lot of cooperation and hard work on your part. I'm willing to explain each aspect, such as vital water chemistry aspects including how and why to test for them, what feeds the algae, different foods to consider, ways to get rid of the existing algae, etc. You need to tell me if you want to go further and if you have the time to make it work, as it may take breaking down the aquarium several times and either replacing the rock or thoroughly cleaning them, maybe several times. Your choice.



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