# BBA - temperature/light versus spore density



## sWozzAres (3 Feb 2016)

Great work on the B12 link, although that is just one factor, no more or less important than organics (humic acid) and ammonia. Putting nutrients to one side, I would like to bring up environmental parameters that are known to effect BBA, such as temperature and light.

Assuming BBA is Batrachosporum Macrosporum, it's commonly known as Audouinella Macrospora. As a red algae, it has alternation of generations but doesn't produce a tetrasporophyte. Instead, gametophytes develop directly off the ends of filaments of the 'Chantransia' stage. This can be induced under ideal culture conditions, temperature 20 °C, photoperiod 12:12 h and irradiance 140-160 PAR. I've never seen this in any of my tanks which isn't surprising considering those conditions.

However, the 'Chantransia' stage is perennial, it develops monospores on branches that germinate and grow another 'Chantransia'. This is the only stage I see in my tanks. The monospores that develop on the monosporangia can can be inhibited at 25° with 65 PAR[1]. Since most tanks are (I assume) running at 25° or higher, then you shouldn't expect an outbreak in low light tanks, but if you lower the temperature and have ideal growth conditions, you should get BBA. I suspect this is what happened to this guy...

http://www.plantedtank.net/forums/23-algae/522761-bba-temperature-there-relationship.html

_"We've recently had a bid of cold spell (not like the mainland mind you) and I notice an increase in BBA in my home tank (29G).
Here in the Hawaiian Island the temperature is normally very warm and stable. However, we've had a cooling trend (by island standards) and its been downright cold (again, by island standards) for much of this week. My tank's average temperature has been a near constant 80 degrees, however, this week it has dropped to the low 70's (72 degrees at last check). The BBA which is normally not an issue in my tank had exploded on the top of my plants. The onset seems connected drop in water temperature. "_

He was sitting on a time bomb where the nutrient levels in his tank were ideal for BBA but growth was being inhibited by higher temperatures. When the cold spell arrived, the BBA suddenly bloomed.

This guy had similiar problems...

_"Would lower tank temperature promote BBA?? My tank temperature is fixed at 78 degree, using 2 Tetra heaters. I have issues with BBA on my powerhead, the gravels, and some small sections on the tank. Some on my crypts. During summer, I don't remember having to deal with BBA at all and the temperature was consistently at 82 to 84 degree. The tank parameters haven't changed. In fact, now, I have to reduce my lighting duration and intensity."_

and

_http://www.plantedtank.net/forums/23-algae/821873-colder-temperature-bba.html

"I've had bba outbreaks in the past and I recall the water was probably in the mid 70s when it cropped up.
I do not recall bba problems with the warmer 80 degree water I've been using the past few years."_

Inhibition by high temperatures is also backed up by field studies...
_
There was a seasonal pattern and C. macrospora was not observed in late July to September. During this period, the water temperature was almost always more than 30°C.[2]_

And by more anecdotal evidence since my tank is 26° and the BBA tufts growing in low light (shaded) and low flow have a very low count of monosporangia whereas the ones growing in high light, high flow have a high count of monosporangia (see pictures below).

*Hypothesis: In low light tanks with nutrients ideal for growing algae, temperatures greater than 25C will inhibit BBA. Once the temperature drops, BBA will flourish.*

In high light tanks, temperature doesn't have the same effect but instead daylength determines monosporangia count. You can't turn off monospores like you can with low light, but you can minimize them. Long days (16h) will result in 3 times the count of monosporangia than short days (8h).[1]

Since high light tanks have more frequent water changes, BBA is likely to be inhibited primarliy by lack of nutrients, B12, organics (humic acid), ammonia etc coupled with the fact that these tanks often run at short days (<8h).

*Hypothesis: In high light tanks with nutrients ideal for growing algae, spore density is determined by photoperiod. Less than 8h will minimize spore formation.*

References
1. Blue-greenish acrochaetioid algae in freshwater habitats are “Chantransia” stages of Batrachospermales sensu lato (Rhodophyta)
http://sauber.dzb.ibilce.unesp.br/~orlando/MorphAcroch(Proof).pdf
2. Recent introduction of a freshwater red alga Chantransia macrospora (Batrachospermales, Rhodophyta) to Okinawa, Japan
http://www.aquaticinvasions.net/2009/AI_2009_4_4_Kato_etal.pdf

BBA under low light, low flow, 26C, notice the lack of monosporangia.


BBA under high light, high flow, 26C. Notice the monosporangia.


----------



## AndyMcD (4 Feb 2016)

SWozzAres, very interesting.

You may find this paper interesting:
https://www.researchgate.net/profil...in_culture/links/555ca06208ae6f4dcc8bc9a2.pdf

This suggests that some of the algae they tested grew best in environmental conditions that 'made sense' - low light + lower temperatures OR high light + high temperatures, but not so well in low light + high temperatures OR high light + lower temperatures that you wouldn't find in nature.


----------

