Cyanobacteria, How do I get rid of it?

[Emyr]

I have had cyanobacteria in my tank for about 3 weeks now and cannot get rid of it fully.

I do 30% Water changes every week. Dosing all the Seachem plant ferts, Have well over enough light and pressurized co2.

I have been manually removing it but it isnt going. Wondering if im dosing enough Nitrates? I am cautious of dosing nitrogen as I worry that it could increase the growth of cyano as well as other Algae.

I have a slightly high phosphates and so have added a phosphate remover.

I read recently that redish tint lights promote the growth of it? I have a tropica original tropical t5 tube as part of my lighting and it has a very red tone to it. Wondering if I should replace it with a whiter daylight tone bulb.

Thoughts, opinions, ideas?

Help with this would really be appreciated, it is ruining my scape.

 

[George Farmer]

Clean your filter and as much BGA as possible.

Turn off CO2 and perform 72hrs blackout.

50% water change and filter clean again.

Don't worry about PO4. The Arcadia lamp is fine for plants. Only change it if's not your taste.

 

[Emyr]

Have been cleaning the filter massively most weeks.

I was thinking about this but If I perform a blackout my HC and Hairgrass plus other plants will die though surely?

Should I be dosing nitrogen more frequently then or anything else about the nitrogen?

I was thinking about changing it anyway so I think I might, Was going to get a Giesemann T5 Powerchrome Midday.

Thanks alot George.

 

[Dan Crawford]

Hi, in my experience the plants actually do fine during the blackout with a strange explosion of growth! Blackouts are your best way to stop BGA so you need to decide whether you want to put up with it or subject your plants to a blackout, to me its a no-brainer.

BGA doenst like flow IME so try and add some more flow. I'd also suggest upping your Nitrate addition, I don't know why but it worked for me!

 

[Emyr]

But with plants such as HC I worry that they will just die off and as they are expensive plants Its a risky idea. But if you think it will be fine then I may go for it. Need to get rid of the damn cyano. I have loads of flow in the tank but will give upping the nitrates a go.

 

[Matt Warner]

Hi all. I have just finished doing a blackout on my tank because I had a small cyano outbreak. I removed the covers and the plants had actually grown quite a lot with no light at all which was weird! I did a 50% water change, vacuumed out as much dead cyano as I could and dosed fertilisers. Also I have a juwel standard internal filter and a tetra ex700 external filter. I was finding that the flow patterns were working Against each other. So I found a spray bar to fit into the juwel pump outlet so that both filters spray bars work with each other instead of against each other. I also think I had the lights on too long at about 10 hours duration. I have cut them down to 8 hours now so hopefully all of these changes will help. I'm also adding more nitrate in my EI dosing as I think this was the root cause, but all the other things were not helping at all.
Don't worry about killing your plants, they will be fine without light for 3 days. They will soon start growing again when things return to normal.
Hope this helped

 

[Emyr]

Why do you think that could be that they would grow without light? mysterious. So to do a blackout I need to cover the whole tank up with a blanket or something to stop any light? I will dose add more nitrates. After the blackout do I put the lights on slowly like for 6 hours then raise it up by one each week or should I just turn them straight on after 72 hours back to 8 hours a day? Thanks Everyone.

 

[Matt Warner]

I wrapped mine with black bin bags doubled up just to make sure. It doesn't matter what you use, just make sure no light at all enters the tank. Make sure you turn the co2 off first too and agitate the surface well with power heads or filter outlets. When the blackout is done, do a 50% water change and suck up any dead bits of algae. Then you need to add more nitrate and improve flow if necessary. 8 hours should be fine but don't turn the lights on straight away, allow the fish to get used to the light gradually.
I think they must of grown with the lights off because the plants stored the nutrients up and then grew a bit while the lights were off.

 

[niru]

I think there isnt anything mysterious about plants growing too much during a blackout.

In general, plants are more busy with photosynthesis, food making & storing during light-ON time. At nights, they spend time & this food in repairing, growing, etc..

During a blackout, since there isnt any raw material to make food, plants simply use the available (stored) food to grow. Since they can do this for much longer hours now as their resources arent divided into cooking, husbandry & growing. So thats an explosive growth to us.

However, AFTER the blackout, the plants are really low on their food storage as in-house rations are pretty low by this time. So now they have grown, but are feeling weak... This is the time to be aware of. After the WC, make sure that plants have unlimited nutrients (in EI sense), CO2, flow, light etc.. I guess, with light its better to slightly reduce it than the pre-blackout levels, but then increase it back within a week or so.. (No point in forcefully over-feeding someone whos gone weak due to starvation, just make sure that all the dishes are available on the table & let them choose!).

In this regard, plants which have sufficiently well stocked food reserves before the blackout fare quite well afterwards. Slightly fisruptive fish make a more vulnerable scenario as well (particularly if you havent fed them during blackout).

cheers
niru