Cyanobacteria???

[severum mama]

Ok, some of you all may remember that my work let me set up a 55 gallon tank for our clients (I work with people with dev. disabilities and they LOVE their tank). So far the tank has 6 flame tetras, 10 green fire tetras, and 6 juvie angels, with bodies about the size of a quarter. Yes, I know that 6 angels is too many to be housed in the tank long term, but I am trying to grow them out and get them to pair off. Anyway, the tank is moderately planted with sand substrate, and filtration is 1 Emperor 400 and 1 Aquaclear 200. I've been testing the water regularly and changing 25% per week, except for last week when my aquarium class ran out of time. It's been set up for a couple months now and so far everything is doing great. I test the water regularly and always show ammonia=0 [acronym:258c6ff952="Parts per Million"]ppm[/acronym:258c6ff952], nitrite=0 [acronym:258c6ff952="Parts per Million"]ppm[/acronym:258c6ff952], nitrate=5 [acronym:258c6ff952="Parts per Million"]ppm[/acronym:258c6ff952], pH=7.0.

My problem is, I've got blue green slimy disgusting crap growing all over the sand and rocks, and there's some on the plants too. I've tried to research it and it sounds to me like cyanobacteria. I don't use [acronym:258c6ff952="Carbon dioxide"]CO2[/acronym:258c6ff952] or decent lighting or anything, I just have some low light plants in there. How in the world do I get rid of this? I've heard that a blackout would work, but doesn't it just come back some other time? I've heard of using erythromycin (Maracyn), but doesn't that harm the bio filter? With the angels in there I definitely don't want to do that. I've heard that low nitrates can be a factor, am I keeping my nitrates too low at 5 [acronym:258c6ff952="Parts per Million"]ppm[/acronym:258c6ff952]? Is this stuff harmful to fish? Are there any fish that will eat it?

Thanks for reading this long post and sorry if it is in the wrong forum.

[lmw80]

severum mama - if you try and take off the algae, does it come off in blankets? Also, does it have a distinct smell to it? Maybe like a cucumber....

The two methods you mentioned are the only ways that I know of to get rid of [acronym:94689f6ecc="Cyanobacteria"]cyano[/acronym:94689f6ecc]. I believe the blackout is for 5 days, It shouldn't harm your fish at all. With erythromycin, I personally have never had a problem when using this for [acronym:94689f6ecc="Cyanobacteria"]cyano[/acronym:94689f6ecc] or fish illness. Whichever method you choose, [acronym:94689f6ecc="In my opinion"]IMO[/acronym:94689f6ecc] is more of a personal preference. Many aquariusts would rather try the natural way before adding chemicals, and some don't mind using chemicals.

Whichever way, make sure you remove as much of the [acronym:94689f6ecc="Cyanobacteria"]cyano[/acronym:94689f6ecc] as possible before starting the treatment.

[JHawk]

I had it too with a new tank set up in the fall....The antibiotic treatment did the trick. (It is a bacteria, not an algae. But I bet you knew that). I did not notice my biofilter being impacted in the slightest. I googled it and read all about various treatment options. The was one that I found that didn't overkill the antibiotic dosage. If I find the link, I will let you know.

[lmw80]

I forgot to mention before, if you choose the medicine path, take out any active carbon in your filter before starting.

[severum mama]

I already took it out, I was only using it for a couple weeks until perams stabilized. But wait- I've got 2 Emperor filter cartridges in the Emp 400, these have activated carbon in them already (the only thing I don't like about the Emperors). Should I take out the cartridges? If I need to it's looking like I will try the blackout since I don't want to lose the mechanical filtration ability on one whole side of the tank. I don't have the extra media baskets to use with filter floss because my work acquired the tank and filter used, and when I got everything out to clean it a client spilled antibacterial hand soap all over the media baskets so I'm afraid to put them in the filter.

Ok, so I've done a little research about the blackout method, and I read that you should do a [acronym:02bc37fc5d="Partial water change"]PWC[/acronym:02bc37fc5d] before and after the blackout. The source I read (don't remember what it was) said to do a 50% [acronym:02bc37fc5d="Partial water change"]PWC[/acronym:02bc37fc5d] before and after- that seems like a lot of water to be changing in a tank where the nitrates are only 5 [acronym:02bc37fc5d="Parts per Million"]ppm[/acronym:02bc37fc5d]. If low nitrates can contribute to the problem, wouldn't massive PWCs only lower the nitrates and in turn make the situation worse? Should I just change the regular 25% instead? Thanks again for all your help.

[Billsgate]

Well, I too believe that it comes from a combination of low light and low nitrates (always less then 5ppm). I had some serious [acronym:473e5c91e5="Cyanobacteria"]cyano[/acronym:473e5c91e5] problems, tried the blackout, which removed most of it, but it came back. So I used medication, which did the trick, but after a month I was back to where I started. A couple of weeks ago I decided to take out most of the stern plants, on which the [acronym:473e5c91e5="Cyanobacteria"]cyano[/acronym:473e5c91e5] first developes. (It always started developing in the same place).
So now I just have some stern plants and allot of Java fern and anubias. No more [acronym:473e5c91e5="Cyanobacteria"]cyano[/acronym:473e5c91e5] growing. Ooh, and it also grew on duckweed that I had floating in my tank.

Good luck.......maybe you'll be luckier then I was!

[severum mama]

AAAAHHHHH! This stuff is really stressin' me out. I guess the blackout will begin tomorrow.

[lmw80]

good luck! keep us updated!

[severum mama]

Well, I changed my mind and decided to go with the Maracyn. Do you have to use it full strength for it to work on [acronym:792ce6622d="Cyanobacteria"]cyano[/acronym:792ce6622d]??? I mean, it's not like I'm actually treating the fish for anything, you know? I didn't read the directions before I bought it and it says you're supposed to use 1 tablet for every 10 gallons for 5 days. Well, that would be a lot of money and I don't think my work will go for it, would it work to cut the dosage? It seems like an awful lot of antibiotics to use on fish that aren't even sick.

[lmw80]

I have heard of success stories of using maracyn at 1/2 dose for [acronym:d7be00130d="Cyanobacteria"]cyano[/acronym:d7be00130d], although personally, since my tank is only 20, I use it at full dose.