Cyanobacteria how to get rid of it without chemicals?

[julielynn47]

I hope I spelled that correctly. I have this in my 75 gallon, which has not even got fish in it. It just appeared a few days and I have no idea how to get rid of it. It has turned my light colored sand green. It is on the plants, rocks, everything.

I have read that you need to add an air stone...nope...got one with lots of bubbles going. I have read to make sure you have a lot of water movement...nope again as I already have that. Read that you might be overfeeding...nope, no fish, no food has ever gone in this tank.

Any ideas how to get rid of it without using chemicals? And any other ideas how it got in the tank to begin with?

 

[Byron]

You are certain it is cyanobacteria, and not algae? I ask because cyanobacteria is caused by organics in the presence of light, nothing else. This is why it usually occurs in heavily-stocked tanks or tanks that are not maintained well, fish overfed, etc. I have had cyano appear due to the filter not being cleaned often enough, or the substrate not cleaned, etc. Water flow has nothing to do with it; in fact, in the one tank where I did have it twice, it was first present next to the filter return where the water current was strongest.

Without fish, one would assume organics are minimal. Tap water can be rich in organics though, this is what causes bacterial blooms in new tanks without any fish. I wouldn't think this would be sufficient for cyano, but... maybe.

The only safe way to deal with cyano is reducing organics. So-called "blackouts" will usually cause it to die off because being photosynthetic it needs light, but it will only return if the organics are not reduced. Certain antibiotics will obviously kill it, as it is a bacteria, but these are never safe or wise with fish (I know you don't have them, just noting this) as fish can be affected by antibiotics.

If it is slimy and easily rubs off in sheets with your fingers, leaving them green, it would seem to be cyano. Otherwise an algae.

Byron.

 

[julielynn47]

I just pulled a lot out of the tank and washed rocks. It is bright green and it is in sheets. I can actually pinch it between my fingers and pull it out. And it stinks! Gawwwwwwww what a strong smell it has. It is slimey but I didn't notice any green staining my hands.

I haven't been doing a lot of water changes however. I didn't see much need because I have no fish yet. But maybe that is the cause?

 

[Byron]

I just pulled a lot out of the tank and washed rocks. It is bright green and it is in sheets. I can actually pinch it between my fingers and pull it out. And it stinks! Gawwwwwwww what a strong smell it has. It is slimey but I didn't notice any green staining my hands.

I haven't been doing a lot of water changes however. I didn't see much need because I have no fish yet. But maybe that is the cause?

Cyano usually smells more like...well, organics I guess. Not foul like sulfur or eggs, such as do anaerobic patches in the substrate if disturbed. The brown organics in a dirty filter remind me a bit of cyano.

If it is slimy, in sheets, and dark green, it is cyano. Otherwise an algae. I am still puzzled about cyano in a tank with no real organics. But given that cyano was the first life to appear on this planet, it perhaps shouldn't be that surprising.

Do you have many plants? If you are fertilizing the plants, this can contribute. Plus the light intensity.

 

[julielynn47]

I don't know if you would call this heavily planted or not. This picture was taken about a week or so ago before the cyano showed up.

I use Flourish Comprehensive root tabs and liquid. And actually, the green stuff smells a lot like the FC, but just a lot stronger

Right now it does not look that clean. The sand has a film of green on it now and the rocks were green. I pulled them out and rinsed them. The stuff just rinsed off in a sheet.

 

[Byron]

View attachment 82754
I don't know if you would call this heavily planted or not. This picture was taken about a week or so ago before the cyano showed up.

I use Flourish Comprehensive root tabs and liquid. And actually, the green stuff smells a lot like the FC, but just a lot stronger

Right now it does not look that clean. The sand has a film of green on it now and the rocks were green. I pulled them out and rinsed them. The stuff just rinsed off in a sheet.

That tank looks familiar . At this point my suggestion would be to get some floating plants. Unless I'm getting confused over different threads, the light was determined to be good, so it may be a question of getting the plants to use more of the nutrients/organics. While light is not the prime cause of cyano, it has to be present with the organics. I had a touch of cyano in a 10g tank that as an experiment sat in front of a west-facing window, only on the tank glass next to the window. The light was stronger obviously, and the organics were present. The same tank removed away from the window and with just the tank light of two 9w CFL bulbs never develops cyano.

How much liquid Floruish Comp are you dosing? I had cyano in my 70g and it disappeared but in addition to more thorough cleaning I had to stop the FC. Fertilizers in the water column increase the total nutrients/organics and that is what you want to curtail.

Byron.

 

[julielynn47]

I use a capful 3 or 4 times a month. That may be too much? I am really bad about just adding it when I think about it. So once a week is pretty much what it gets. But I do have root tabs in the tank too.

Aside from the hornwort, what other floating plants do you suggest?

 

[Byron]

I use a capful 3 or 4 times a month. That may be too much? I am really bad about just adding it when I think about it. So once a week is pretty much what it gets. But I do have root tabs in the tank too.

Aside from the hornwort, what other floating plants do you suggest?

IF the cap is the one on the 500ml bottle of FC, it holds 5 ml. This treats 60 gallons, according to Seachem. Dosed once a week (on their instructions).

I have had to reduce my doses to avoid brush algae in a couple tanks. I've done more experimenting over the past couple of years with fertilizers as I have two tanks that are high in organics (for reasons I cannot discover). Using the substrate tabs more often than what the instructions suggest allows me to reduce the liquid additive, and this made a big difference, both in algae and the plants' response. The nutrients in the tabs do not get directly into the upper water column, according to Seachem, and I am satisfied there is some truth in this. I replace them every 6-8 weeks now, one next to each of the larger swords, red tiger lotus, aponogeton, and one species of crypt. I still use the FC but at half strength (half the dose for the tank volume) and sometimes not even this.

Using less FC and including the Flourish Trace seems to have made a difference too, again for both the plants and the algae.

Also remember that a 60 g tank is more likely around 45-50 gallons of actual water when you have substrate, decor and plants displacing the water. And a 75g is more likely 60 gallons if that. I have caused brush algae more than once simply by using too much FC, and I have brought it under control by reducing and even eliminating the FC, so I know it is relevant.

You need to be regular. I do 60% water changes every Sunday, and dose the FC on Monday, and the Trace on Thursday (this Trace is only in some tanks).

 

[StevenF]

I ask because cyanobacteria is caused by organics in the presence of light

Organic molecules sometimes contain suffer, sometimes nitrogen, phosphorous and other elements that are needed in regular fertilizer. I have also read that cyanobacteria is caused by organics. But i question that claim for one simple reason there are no test kits available to measure "organics.

The claim probably originated when someone removed organics material from the tank and then had it clear up. Just because it cleared up with the removal of the organics doesn't mean it was caused by organics.

That said when I recently tried making my own fertilizer per Tom Barr's posted Estimative index instructions Cyanobacteria and green spot algae vanished. Unfortunately the one Algae I was most interest in clearing, Hair Algae wasn't touched. Flourish Comprehensive is a little week in nitrogen, phosphate, and I think sulfur. Most tanks have plenty of this from fish food. But you don't have fish food. How are your nitrate levels If they are very low you might be deficient in nitrogen. If you have epsom salt your can try adding that (it contains magnesium and suffer. Another thing you could try is to get fish. Maybe the waist from the fish would correct the issue.

 

[julielynn47]

I am supposed to get to go to town this weekend and get some fish...if nothing happens to interfere with that plan. So far, every time I have tried to make it to a pet store something has came up. But hopefully this weekend will be the one LOL