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Re: Red Algae

Jonathan Kirschner wrote...
>Dave Whittaker wrote:
>>I've been trying to deal with red algae (brush/audouinella) for more
>>than a year in my 30 gallon. It thrives on low pH/CO2 injection and
>>bright light and grows almost as well as the plants.

By the way, approximate parameters of the water are
pH 6.3, CO2 15-40 ppm, KH 1-2.5, temperature 78 F to 82 F.

>Dave, it's not that simple.  True, it grows well in the presence of
>bright light, but it also requires an excess of nitrate or phosphate.   I
>am injecting uncontrolled DIY CO2 and have VHO lamps operating
>11 hours a day on a 20 gallon tank and have no red algae at all.
>None.  Believe me, when I first started out I had a terrible outbreak
>because of something I added to the water that I shouldn't have, so I
>know what it looks like and how hard it is to get rid of.

Describe your pH, DH, KH and what you added.

>> Since I don't test for iron, levels may be a bit high.
>Excess iron would more likely give you an outbreak of slimy, green
>Cladophora thread algae in the presence of bright light.  Also not

I just mentioned it. In fact I cut the proportion of micronutrient
mix in the PMDD and it seemed to help with the hair algae.

> >I do keep nitrates at 3 to 10 ppm
>Are you absolutely sure about this?  I just had a discussion off line
>with somebody who thought that he had low nitrates, too.  Don't
>forget that if you are using the LaMotte nitrate kit, and probably most
>of the others,  you are measuring something called "nitrate as nitrate
>nitrogen".  In order to determine the actual level of NO3 in your
>water you must multiply the results of your test by a factor of 4.4.
>>and I doubt that one could detect a phosphate atom in the tank.
>Again, are you sure?  If your nitrate levels are really as low as you
>say they are, then I can only think of an excess of phosphate as
>being the source of your troubles.
>>We found cessation of the CO2 injection, or prolonged light
>>deprivation to be somewhat effective. It doesn'tdo much for the
>>flora though.
>Drastic steps that you should not have to resort to if your nutrients
>are in balance.

Jonathan has suggested that I had an nutritional imbalance in
my tank, i.e.. nitrate or phosphate levels that were too high
and which encouraged the black brush algae. It is a necessary
condition that phosphate be present for either plant or algae
growth. Upon reconsideration it is probably true that my
phosphate levels were not zero. I also believe that the
success of the audouinella was determined by near perfect
conditions of pH, CO2, and lighting. These same conditions
favoured the plants. The nitrate levels were as stated,
3 to 10 ppm measured with the Wardley nitrate kit.

In the last three weeks little phosphate has been entering
the system. PMDD additions have continued. Recently two SAEs
have died, from all appearances due to starvation, and I've
decided to recommence feeding.

I have just re-read several articles on SAEs including some
authored by Neil Frank, Lisa Sarakontu, and Doug Underwood.
Over the years many people have testified to the ability of
Crossocheilus siamensis, the siamese algae eater, to eat
black brush algae (audouinella). Some other persons have
spoken of their having eradicated  red algae from a tank
in days.

Well, I have had a planted 30 gallon aquarium with several
types of algae, including black brush, up and running for
almost two years now. I use PMDD, carbon dioxide infusion,
and 175 watts of metal halide lighting. The plants grow well
and so does the audouinella. Two SAEs have been resident
for about 18 months. They did a lot of grazing, but were
overwhelmed by the algae growth. I never saw them eat the
black brush type.

Thinking that this was just a matter of logistics I moved
these two to another aquarium and introduced 32 smaller
4 CM specimens. All other fish except the bristlenose were
removed. I fed them for three days to insure that they
would survive, and then stopped the feeding. Last week I
mechanically eliminated almost all of the black brush algae
(98%). About a month has now pasted since their introduction.
The plants are free of all algae except this one type; the
tank is pristine. The SAEs graze everywhere, but they avoid
the audouinella. I have never seen them actually take a
mouthful. If they were eating it, they would be congregating
around the numerous tufts and they don't.

Doug Underwood has suggested in a previous post that the fish
consume the new growth, and that the old growth declines on
its own over time. This is an interesting theory. Should this
be the case, there is little to be gained by starving the fish
in the hope that they will eat the mature filaments. 

The algae seems to be neither growing nor proliferating;
occasionally a tuft will fall to the bottom. It occurred to
me that the reported disappearance of red algae in tanks
containing starving SAEs might be due not to the fish but
to the effects of phosphate deprivation. I might add that
the growth of my stem plants has slowed down considerably
as well.

A local fish shop keeps the SAEs in a tank that contains an
ornament with guess what, attached black brush algae. They
don't touch the stuff, nor do they eat a particular variety
of hair algae also present.

I am a little disappointed that to date no one has called into
question the blanket statement "siamese algae eaters eat red
algae." The numerous letters that Doug has reportedly received
testifying to the opposite casts doubt on the truth of this
statement. That they eat the spores is a hypothesis.

As you may have guessed, I have some basic questions.

1) Has anyone ever actually seen an SAE eat black brush algae?

2) If so, how old/large was the individual?

3) Has anyone ever introduced SAEs into a tank containing
   audouinella and seen the algae disappear all the while
   maintaining adequate nutritional levels for the plants
   and algae? If not how do we know that the algae decline
   is due to the efforts of the SAEs and is not the result
   of lack of nutrients.

By the way, I really love these little guys.

Dave Whittaker
ac554 at FreeNet_Carleton.ca