Issues With Blue Green Algae

having a issue with blue green algae....

To get rid of it I plan on manually removing as much as I can then use Chemiclean to kill off the rest.

So it does not come back i was thinking of adding another filter to my tank even tho I am already over filtering

Currently I have a Aqua Clear 110 and Rena Filstar xp4 running on the tank with a powerhead for extra circulation

So shoud I ad this rena xp2 I have laying around?

or is the cause of this BGA from something else?

no chemiclean..no dosing anything...manually remove what you can in conjunction with water changes...lots of water changes...went through the same thing myself with my 75 gal discus tank....

nick_76 wrote:no chemiclean..no dosing anything...manually remove what you can in conjunction with water changes...lots of water changes...went through the same thing myself with my 75 gal discus tank....

This worked in one of my big tanks too along with more powerheads to create more aggravation on the surface. However, on my 30 gallon NOTHING seems to be working. Just yesterday I conducted 100% water change while cleaning every surface I could and removing plants that where past saving. I then dosed with Anti Bacteral medication. Today, another 20-40% water change & another Med dose. Tomorrow will be another water change then see how it goes.


@PlantedAquariumSeattle, let us know how it goes with your tank .
The cause could be from a few things . Not enough water flow, combined with nitrogen deficiencies, general low water quality. In my large tank i believe it was nitrogen deficiencies combined with water flow. Once I corrected those, the bacteria went away & hasn't came back. I think the same for my smaller tank since its a planted mini. I may install a different filter as well. A small canister with a spray bar system to maximize flow throughout the tank.

I have recurring issues with BGA and none of the causes mentioned apply. I've had it in a river tank that was a torrent. All of my tanks are over-filtered. I have plenty of nitrates, though not too high. My water conditions are well kept. The only thing that's had an effect, along with cleaning & water changes, is varying the light exposure. Complete blackout for a day or two, then varying times of exposure. I have cured some tanks and some goes away for a while only to return. I'd really like to know what allows this stuff to thrive. I hate it!

I nuked a 10g over the weekend because of this stuff - completely cleaned it and started over with a different substrate (punted with safe-t-sorb and went with sand).  I had over-dosed with nitrogen (potassium nitrate) for quite a while per Roy's BGA treatment guide and that didn't seem to help much.  As plaamoo said - the only thing that really worked was a complete blackout.  But then the stuff just grew back.  I admit I could have performed more water changes in it, but the tank was empty so I had little motivation to do that.  Hopefully it'll stay gone now... fingers crossed.  It's nasty stuff...

I have been doing 50 percent water changes once a week for the past couple months and removing as much of the bga as I can everytime. My tank was doing fine prior to this epidemic with minimal algae then the bga appeared out of no where. I have been recommended chemiclean by many. BGA is actually a cyanobacteria and chemiclean is a.antibiotic that kills this bacteria.


So my plan is tomorrow (water change Wednesday for my tanks) I will manually remove as much as I can, do my 50 percent water change, then dose the chemiclean as directed. Wait 48 hours and do the recommended partial water change.

I will try to remember to take before and after pictures.


Side note in my 10 gallon low tech planted tank it was algae free. Put a few plants with BGA on them and it died off and plants began to thrive. This stuff sucks...

I had cyanobacteria in my 10 gallon. Started treating with Flourish Excel and it went away within days. I've not had it come back since.

We have it at work and it is a pain. Apparently another imbalance is phosphates, though I don't see it diminishing even with the addition of removing phosphate. We did notice the tanks with plecos didn't have much if any BGA, so we started moving them around along with pulling out what we could. Not that a fish should be the source of how to get rid of an algae or look alike -- we just have them available and could do such a thing.

Here is some specs of my tank so everyone can get a idea of what may be causing the BGA

55 gallon tank
4x 54 6500k t5ho light fixture 2 bulbs run from 1pm-7pm other 2 from 3pm-5pm
10lb co2 cylinder with regulator diffused via inline atomizer truns on 11am off at 6pm
Aqua clear 110, rena filstar xp4, and small power head
inline 300 watt hydor heater 76 degree
weekly 50% waterchange
medium-heavily planted
(was dosing dry ferts ei method)


what do you think I can change?
Too much light? ( had a 4 x 65 watt light running all bulbs for 7 hours a day had minimal algae)
I want to stay in the medium to high light area
Can add another filter rena xp2 if needed

open for any suggestions at this point

Well, you could try adding a ton of nitrogen... not sure what that would do for other algae. It did slow my BGA down when I started doing that.

Here's a post of Roy's about the problem:

[You must be registered and logged in to see this link.]

You should get yourself a sunsun with uv canister filter. This will solve your problem.

How, exactly, will a UV canister filter remove cyanobacteria from tank surfaces (substrate, leaves, glass, etc.) ?

I have absolutely no experience with this type of algae, but here's just a thought: maybe all the water changes and cleaning are actually hurting, not helping?

If you keep supplying them with more of what they need to grow with each water change (whatever it is they need must be in the water supply itself if it keeps recurring), they will keep growing. It seems to me like maybe every time you do a WC, it is giving the bacteria a little more (of whatever it is they eat) to work with.

Combine this with cleaning a lot of it out each time, which gives the little bit of bacteria that you can't always get an abundance of resources (less competition for whatever makes it grow), and I can see why it keeps coming back.

I might try the blackout if it's really bad, then not do a water change and see how it works. It doesn't sound like it could work out any worse than it already has, if it keeps coming back anyway.

Blackouts do work, for a few days.  Then it comes back  With or without water changes.  With or without adding potassium nitrate every day. With or without physical removal.

I like to do more frequent, smaller water changes. Every day for several days. It doesn't like to be disturbed. One other thing that I noticed was temp fluctuation seemed to also have an effect. I unplug all of my heaters sometime around May, then plug them back in when it gets cool enough. Last year when I did this the BGA seemed to vanish. I thought I had something. But this year, not the same. It's still here! I have read articles explaining how the constant temps that we maintain in aquaria are beneficial to the growth of some harmful bacteria. BGA is a bacteria.

pbmax wrote:Blackouts do work, for a few days.  Then it comes back  With or without water changes.  With or without adding potassium nitrate every day.  With or without physical removal.

Well, I guess that throws my theory out the window. I have no other ideas :/

Excel excel excel.

I've read that cyanobacteria doesn't care about excel... besides which, I had crypts in the tank which aren't terribly excel-friendly. Not that it matters anymore... I threw out everything in my infested tank except the filter, heater, and temp alarm. I soaked those in 150F water. I'm not entirely confident this killed it all, but time will tell. I'll excel the crap out of it now if it comes back.

PlantedAquariumSeattle wrote:having a issue with blue green algae....

To get rid of it I plan on manually removing as much as I can then use Chemiclean to kill off the rest.

So it does not come back i was thinking of adding another filter to my tank even tho I am already over filtering

Currently I have a Aqua Clear 110 and Rena Filstar xp4 running on the tank with a powerhead for extra circulation

So shoud I ad this rena xp2 I have laying around?

or is the cause of this BGA from something else?

Is there any way you could post a couple clear pictures of this stuff. Are you absolutely sure its cynobactera?

All of the BGA is now gone.

I removed as much as I could then did a water change after that I added a airpump/airstone and dosed the recommended amount of chemiclean.

Waited 48 hours and did another waterchange.

Before I even did the water change all of the BGA was gone.

I did not manage to take any before pictures since I forgot.

My water seems to be much clearer now and none of my plants or fish were harmed.

Are there instructions on the Chemiclean on how they recommend prevention of the return of the BGA? Are they just repeat when it returns? Or dose on a regular basis? Just curious.

Nothing about prevention. Just says repeat if necessary and can be used as component of monthly maintenance.

I hope this does it for you; fingers crossed!