cure for blue algae !!

[edmondsng]

Hi,

My tank has been infested with blue algae recently. How do I eradicate this horrible looking organism?

What's causing it? There are not a lot of fish in my 300L tank.

Please help

Ed

[Caryl]

Do you mean blue/green algae, cyanobacteria? This forms slimey sheets over everything and can be pulled off in sheets too. It also makes the tank smell quite swampy.

[edmondsng]

yes it is

[Caryl]

Seems to be various answers when asked what causes it - too few phosphates, too many phosphates being 2 of them :-? Tanks with a high pH are prone to it (I have a full blown case of it in my Malawi tank at the moment but since there are no plants in there I just leave it. Fish won't eat it.

Remove as much of it as possible by hand then turn the lights off and cover the tank with a blanket for a few days. Keep an eye on the plants though as they will not cope without light for long.

Little water changes often may help as well. Do you do regular water changes?

I found nothing worked for me (I got an infestation in my tropical community planted tank from some plants I added to the tank) and finally resorted to using Erythromycin, 200mg per 10 gallons (40L?). This is a prescription only medicine so you need to sweet talk your GP. I work for a doctor and he took great delight in going up to the A&E dept at the hospital and asking for a few Erthromycin pills as his receptionist has algae! The Erythro will kill it off very quickly so it is important to remove the dead stuff ASAP or it will pollute the tank. Keep track of your ammonia and nitrite levels as it kills off bacteria - including those in your filters. I dosed my tank with an AquaClear 500 running to no ill effect that I could see but my tank was also very lightly stocked at the time. Be prepared to do water changes to reduce the ammonia and nitrite levels if required.

[TerminalAddict]

mmm I have lots 'o' plants .. but nothing expensive ... I guess I get the drugs, or kill the plants

[spooky]

Before going for the drugs I'd definitely recommend turning the lights off for a couple of days. It doesn't get rid of all the algae, but the algae takes a serious hit and the plants barely notice. Also keep the plants well supplied with CO2 and a phosphate-free fertiliser - let them out-compete the algae for the shared resources.

If that sounds too much like hard work, just reduce the amount you feed the fish to try and limit the phosphate levels.

That last advice is sort-of generic anti-algae advice assuming the problem is high phosphate levels. As Caryl points out this isn't necessarily true - blue-green algae seems to thrive in non-standard water conditions (I get it betwen the java moss and the glass and only there, I assume its a sort of micro-climate). You could also try doing some water changes in quick succession to try and swing the water parameters away from what they currently are and hopefully the algae will like it less. (Hopefully the water chemistry will swing towards what the fish like, but be careful.)

[alanmin4304]

Blue green algae is a bacteria which thrives in eutrafied conditions. I have a friend with a very large goldfish pond in the country which got over run with it. The problem was it was red. Not only the Irish have red blue green algae. It went away at night and came back with the sun. It sinks at night and rises up during the day by prodocing gas (oxygen I think) It also is a nitrofyer and converts nitrogen to nitrate. I have got rid of it in the past in an aquarium by adding hydrogen peroxide very slowly and carefully. This drives off co2. My guess is that your water is too rich in fertilizer,probably phosphate.

[ramuk]

I just got rid of a very stubborn BGA infestation in my 55 gallon (270 liters)

Initially, I tried cutting down on light, massive water changes, physical removal etc. I even bought 2 flying foxes not realizing that they do not eat BGA.

In any case, after reading up on the internet, I realized the cure to be either erythromycin (antibiotic) or Hydrogen peroxide.

I tried to get a presciption for the antibiotic by calling my vet etc, but he was reluctant to do so. Further, even if you had a presciption, it will cost you $15 to actually buy it. On the other hand hydrogen peroxide is only $3.50 for 100 ml (3%) or $4.50 for 100 ml (6 %).

I bought the 3 %. I removed all the fish from my tank (except for 2 neons). I slowly injected the 3 % (3ml at a time, all 100ml of it) at the bottom of the tank. I kept the filter running (it seems this is important to disperse the H2O2 all over the tank). I moved the fish back into the tank after 3-4 hours. The 2 neons I had left in were a test to see how the fish would take the H2O2. They survived just fine.

The next day, teh algae were WIPED OUT.

Given the price of H2O2, I am now planning to just keep a bottle handy and put in a few drops every week to keep any further algae growth under control.

Of course, this does not target the CAUSE of the

algae problem in the first place. But that is for another day :-)

I hope someone finds this useful.

[alanmin4304]

I think it thrives in eutrafied conditions and since it is a nitrofier I think it will be too much phosphate and CO2 which brings it on. I understand the H2O2 drives off the CO2. I would be interested if people using CO2 injection have problems or it has to be in conjunction with excessive phosphate.

[Luke*]

I had it quite badly in my 4 foot 300L tank and i was injecting pressurised CO2 as well. i knew ethryomycin was prescription only so seeings as it was going to be difficult just overhauled the tank instead (which i'm still in the middle of), this is also to rid it of black beard algae and long stringy brown hair algae. The hair algae was introduced from some plants from a friend who was infected and my tank never recovered. :evil:

So, were my phosphates high too? I don't know, however I didn't overfeed, and I did water changes of approx 50% per week. It was heavily planted and last i tested it it was using all nitrates so registered on NO3 tests below readable.

[alanmin4304]

I could be wrong but I am working on the assumption that it can utalise nitrogen dissolved in the water and so that should not cause a bloom. Also CO2 should encourage the plants to take up phosphate and starve the blue green. Just curious.

[ramuk]

I have also read that BGA can fix the N2 from the air.

Another way to control BGA is to have teh plant called hornwort, which produces something which kills off BGA. Takes a few months to kill a complete infestation.

[JoandWilly]

Hmm i found i get in all the tanks which get some sunlight... once i took the sunlight away it stop growing and slowly dies away... BGA is usually associated with poor water conditions aswell, high nitrates but not sure about the phosphates, have heard it can grow without phosphates.

[alanmin4304]

It is a nitrofying bacteria so it can get its own nitrogen