Getting Discouraged

[Soupy97]

I have had a 40 gallon breeder tank for about 5 months now, and everything in it is perfect. My ammonia is 0, nitrite is 0, and Nitrate is 5ppm (I did a water change yesterday). The only exception is the green, slimy (what I presume to be) cyanobacteria on my sandbed and front glass. It looks awful and over the past week while I was away on vacation has probably doubled in size. It showed up about 2-3 months ago but never had a significant presence until now. The worst part about it is that i'm 90% sure that it didn't just appear in my tank, but was from a plant I bought from the store that had some green "algae" on it.

Im getting very conflicting info on the internet about how to get rid of it saying I should add nitrate, that I should lower nitrate, saying that I should do a tank blackout but also saying that a blackout could mess up the nitrogen cycle after the bacteria dies.

I have no idea what to do and was wondering if I could have some help?

I want to take care of it before it becomes a serious problem.

Thanks

 

[Soupy97]

Does anyone know anything or have any experiences with cyanobacteria?
(Blue-Green Algae)

 

[Fishfur]

I take it you have tried removing it ? It is quite soft, but very messy. I saw a very good article on this somewhere, let me see if I can find it again.

I had it cover the back wall of a newish tank, but once I wiped it off it pretty much disappeared. It did grow in the filter to some degree, until I covered the filter with foil, to prevent sunlight getting in. Tanks are in a south window, so they get a lot of daylight. I have surprisingly little algae trouble though, for the most part. Let me go look for the article.

Edit. Can't find the one I'm looking for, I guess I did not book mark it. But you can use 200 mg erythromycin phosphate/10 gallons water, to help kill off the bacteria.

Physically you have to remove as much as you possibly can. When you go to remove it, take all media out of the filter and replace with filter floss only. It will catch the bits that get away and then you can toss it out and return the media you had.

Ah, just thought, maybe you have a canister filter ? if so, If you can, turn it off, unplug it, whatever. If you have an old HOB, use that to filter the bits out, if not, use a net to catch as much as you can before you turn the filter back on.

It can be related to overfeeding and lack of water changes, so it got worse while you were gone because of that, perhaps. You can't really get rid of it all, it's always there, waiting for favourable conditions. So be really careful not to overfeed, keep filters clean and do regular water changes. If the original cause is not solved it will keep coming back, unfortunately. I think mine was mainly due to the tank being new and having little to compete with it, and now I rarely see any.

It can be a huge pain but it can be managed.

Edit.. it is always introduced, with a plant or even with water from plants or fish, from other tanks. It really can't be totally avoided, you can only make the tank inhospitable for it.

 

[DavidAl]

I do not have firsthand experience with this, but I have read on many occasions that antibiotics with increased circulation is the only way to fix this.

David

 

[Soupy97]

Alright then. I do have a canister filter so I can just turn that off while I start with physical removal. I will look for the erythromycin but I have heard that the chemical can kill some of the beneficial nitrifying bacteria? But either way it seems that that is going to be the only way to really get rid of it. I also heard about the increased circulation but $50 for a new powerhead is a bit steep

 

[BBradbury]

Hello Soupy...

Well, I don't believe five months is long enough for a tank to "settle". The fish, plants and bacteria in the water will need to work for some time to level the water chemistry. Most, if not all problems with tanks have to do with the water. It takes a long time for the chemistry to become stable in such a small cube.

Large, frequent water changes will help. They'll keep extra nutrients out of the water. This is the most important thing you can do and these just seem to fix most tank problems. By flushing a lot of pure, treated tap water through the tank, you'll maintain healthy mineral levels that are lost over time.

Overfeeding is an issue. Aquarium fish are small, with very small stomachs. They'll get by with a little food a couple of times a week. They'll forage for every tidbit and do their part to keep the tank cleaner. They'll stay healthy longer. No extras for algae, either.

Floating plants are good too. Anacharis is a natural water filter and believe it or not, it gives off a mild toxin that discourages the growth of many kinds of algae. It's thick in my tanks and I have no visible algae.

I don't mess with the lighting. I don't think that's the problem. But, I just keep low to moderate lighting in my tanks.

Some of this may help.

B

 

[Soupy97]

Alright thanks for the advice. I'll try and keep up with 40% or so water changes every other day for a couple weeks and see if that makes a difference, along with physical removal. I'll lessen feedings a bit too. I'll look into plants, but apparently this is a bacteria so I'm not sure how much plants will contribute. Could it possibly be oxygen/co2 levels in my tank? I have a lot of plants (low light) but no injected co2 or oxygen.

You guys have been very helpful so far

 

[Fishfur]

Low oxygen is not the cause of cyanobacteria. But if your tank is very low in oxygen your fish would be in big trouble.

High temperatures do lower oxygen levels, warm water holds less oxygen, so an air stone can help by improving gas exchange at the surface, which is where gas exchange takes place.

Water naturally has next to no carbon in it, which is why C02 is injected to planted tanks. Plants do need carbon and many can't get enough in the tank without some help, but low light ones typically manage without C02 addition. Low light plants need some feeding and root tabs for the ones that feed heavily, like swords, crypts if you have those.

But plants do use up nitrates, ammonia and generally contribute to better water quality. I had not heard anacharis generates a toxin, that is very, very interesting. I have some, but not a lot, in my tanks. But it's reasonably easy to grow.

 

[Rivercats]

Erythromycin does not harm beneficial bacteria. What you might see is a slight ammonia spike due to the dying bacteria. All you have to do is dose the proper amount (many people like to use Maracyn) for the size of your tank for 5 days. On day 6 do a 50% WC and be sure to keep nitrate levels at 10ppm. Tanks with nitrate levels under 10ppm are more prone to developing cyano (but that isn't the only reason). It also helps to remove as much of the cyano before starting treatment as possible as this helps keep your ammonia spike lower.

 

[Soupy97]

Well I'm afraid that if I use an antibiotic the bacteria could become resistant to it and I would have antibiotic resistant pathogens in my tank.

Would this be an effective solution?:

-Place a powerhead on the bottom of the tank, near the sand bed where the cyano is to increase circulation
-Dose Nitrate for a couple days to increase ppm
-When done dosing nitrate remove as much of the cyano from the tank as possible
-3 day black out (no light, towel over tank, no food, etc)
-Afterwards do water change and place some activated carbon in the filter to get organics

Then if that doesn't work try an antibiotic?

 

[Rivercats]

You can try if you want but just so you know using an antibiotic one time will not cause the bacteria to become resistant to it. I've used this method since the 80's when I've needed to and never had an issue. It also ensures all the bacteria in the tank is killed and that means chances of it coming back is pretty much nil. Other methods can work, don't get me wrong, but the antibiotic is sure thing.

 

[Soupy97]

Alright, I'll look into that more then. I just need to find whatever it is that's keeping it alive and see if I can get rid of that.

Thanks for the help everyone