Cyanobacteria In A Very Planted Tank

[attibones]

I have had for a couple of weeks a small amount of BGA (Cyanobacteria) on the output baffle sponges I made. My filter has a fast flow which was knocking about my plants (and sucking in my snails and plants), so I baffled the intake and return with some sponge. Originally it was just the intake, but the return was still flowing so quickly I needed to baffle the rest of the HOB.

For the most part the "algae" was contained to the return sponges. Now it is catching some of my duckweed and other floaters. I noticed a teeny amount on the intake sponge and a very small amount on the manzanita branch in front of the filter.

I have in this 38 gallon (probably, what, 35 gallons actually?) two 21 watt 6700K fluorescent tubes at 36 inches. Tank is around 76-78 degrees.

I dose Flourish twice a week. Been doing that for about one week. I had been doing once a week for a spell but I thought I may like to experiment a bit. I have one Flourish tablet in the substrate by a mystery lily/red tiger lotus.

My substrate is a mix of fine and medium gravel over organic potting mix.

My tank is planted with vall, sag, ludwigia, duckweed, water lettuce, water spangle, water wisteria, Cyprus helferi, amazon compacta, pennywort, anubias sp, assorted cryptocoryne, and that mystery lily I mentioned earlier.

Tank inhabitants are:
2x nerite snails
?x pond/pest snails (I like them)
3x albino BN plecos
6x breeding peacock gudgeons

Three more peacock gudgeons as well as the first half of my emperor tetra school will be added in a few weeks (they are in QT), so I'm hoping to tackle this issue before I add more fish to the mix.

I haven't tested nitrate yet (and can't until I return home on Monday night), but I'm presuming my nitrate is pretty low. Should I increase the water flow? Can I add an airstone to help with flow or should I remove one of the sponges instead?

I have read that elodea is good at combating this bacteria. How much would I need in this tank?

Any other ideas, thoughts, comments, whatever?

 

[Byron]

Cyanobacteria is a bacteria and not an algae, and it is caused by organics in the presence of light.  Plant fertilizers will add to the "organics" obviously.  I have had it appear a couple times over the past four years, always in the same tank even when it was set up differently (different substrate, fish, plants).  It disappears following a couple weeks of major water changes with a good (more than normal) dig into the open areas of the substrate.  I also have reduced the light duration on this tank by one hour.  And I removed a couple pieces of wood that had it and gave them a very good scrub.
 
The organics in the soil in your tank will obviously factor in, plus you have quite bright light.  Blackouts are often suggested; these will usually kill off what is there, but the cyano will always return if the organic issue isn't dealt with or the light intensity/duration reduced following any attempt to clean it up.  The light adjustment alone may work if the organics are not too high.  I usually reduce/eliminate the fertilization during periods when I am actively bringing things back to normal.
 
Byron.

 

[starlitsunrise]

I agree with Byron about the black out. 
 
I had some of this growing in the sand and some rocks in my 10 gallon tank a few weeks ago, at the time I wasn't using any fertilizers so I don't know how that might affects your tank. What I did was scoop out as much of it as I could, did a 50% water change and covered the tank in a towel for 3 days. I did read that you shouldn't feed your fish during this but I'm a worry wart so I fed my betta and frog on day 2. When I took the towel off on day 4 it was all gone, I did another 50% water change and since then I have been cleaning the substrate better and it hasn't come back. 

Hope this helps, Atticus!
 
ps. I like pond snails too xD

 

[attibones]

Thanks, Byron and Becky.

I noticed when I was adding more plants earlier in the week that there is a spot without gravel. It is entirely soil. Should I cover this up or try to clean it with a gravel vac? I'm worried the soil will go straight up the vac. I don't typically change the water in this tank. I refill it mostly or I do small water changes. I'll do 50% and then see about first reducing photoperiod with no ferts and then a blackout. Presently my lights are on from 2:00 to 11:00, so I have room to cut them back.

I'm hesitant to do a blackout with my plants. Will they be okay? They are kind of important to the tank, as I'm sure you both know. If a blackout for a few days would not harm my plants, what is the best way to do this? Wrap towels or garbage bags?

Thinking I'll go back to only one feet dose a week after I get this handled, and perhaps a smaller amount. I follow the instructions on the bottle and dose accordingly.

I have noticed that is easy to scrape off the cyano so I'll do that too.

Am I missing anything?

 

[Mamashack]

I did a 3 day blackout with towel wraps and absolutely no peeps! All occupants were fine at the end of 3 days including the plants. The fish had lived on the true algae on the glass which was nearly spotless after the 3 days. I'd removed as much of the BGA as I could beforehand and reduced my photoperiod by 4 hrs (and got a timer as my timing was rather haphazard at best!) Now have the lights on in 2 x 4 hrs sessions (mainly to help keep the temp down, but also so that the lights are on when I'm home to see inside the tank.)

 

[Byron]

Many do blackouts, provided you also do the cleaning, but I have never gone this route (blackout).  It may take longer to deal with cyano without the blackout, but I too worry about the plants and fish.  Not saying it isn't safe or won't work, just not my particular choice.  I do the thorough cleanings, water changes, and reduction of organics (feed less, fertilize less, etc).  My last bout of cyano was minimal to start with, and in two weeks I had it gone.  Previously, I had a real bad bout of it, and it took four months, and then it just vanished overnight.  I still can't figure out why it has only been in that one tank and never in the other six when everything is much the same in all of them.
 
One thing to remember, if you do blackout, you will kill all the cyano and algae (if the blackout is for more than a day) and this can cause issues with ocygen levels and ammonia.  Another reason I don't do it.
 
Byron.

 

[starlitsunrise]

Hmm...I honestly hadn't thought about the plants in your tank...all of mine were fine during the black out, but they are low light plants to begin with. From what Ros said I would assume your plants would be alright, but obviously only do this if you feel comfortable with it.  And I think I misread what Byron had posted earlier, as now I see he is advising to go a different route and not the black out. 

If you are really worried about your plants I would try out what Byron is suggesting and then if that doesn't work try out the black out. 

 

[eaglesaquarium]

Plants will be fine with no light for a few days, and the fish... they don't need the light at all.  
 
 
Another option, although not the ideal for all, would be spot treating the cyanobacteria with hydrogen peroxide.   You could pull the sponges and just soak them in the H2O2... and then the stuff on the plants just a small squirt (obviously with no circulation in the tank) with a syringe directly where the cyano is will kill it.  
 
 
But, as pointed out, if you haven't dealt with the cause, it will come back - and fast.

 

[attibones]

Hmm... Well I will first try a light reduction, water flow increase, food decrease (I've been conditioning the gudgeons, but they should be fine with a food reduction), and a careful substrate cleaning. I'll go from nine to seven hours of light a day (the lights are on timers). Then I'll see how the tank looks in a few weeks. If the cyano is not gone in two or three weeks, I'll do a blackout over a weekend.

I just hope it hasn't spread much in my absence. If it has gotten worse, I'll do some spot treatments too.

 

[eaglesaquarium]

The key for the H2O2 is to limit how much you use.

 

[attibones]

How so, eagles? I'm assuming that when I pull out the sponges, I'll just spray a bit on. Will it immediately have an effect? What should I anticipate so I don't over use?

 

[eaglesaquarium]

I meant for the spot treating of plants in the tank...  The H2O2 can damage the gills, I believe, of the fish if used in too high a concentration, but in small amounts, it degrades into just H2O and O2... it doesn't take long to degrade either.  Just be sure to do it in small doses in the tank, and its all safe.
 
 
Doing it outside the tank means you don't have that concern, just a good rinse when finished.

 

[attibones]

Oh okay, thanks.

 

[Lunar Jetman]

Personally I got rid of Cyanobacteria a while ago by increasing flow rates in my tank and by double dosing on ferts for a few weeks. A blackout was a last resort for me and thankfully I avoided it.

 

[attibones]

Double dosing the ferts sounds a bit contradictory doesn't it? How does that work out? Sounds almost too easy. Haha.

Personally I got rid of Cyanobacteria a while ago by increasing flow rates in my tank and by double dosing on ferts for a few weeks. A blackout was a last resort for me and thankfully I avoided it.