Still algae fighting...
a long story with many questions follows:
At first thanks to all who replied to my questions on how to fight algae
about 2 weeks ago by listserver or by email. The bottomline was: I have to see
that my plants outcompete the algae, that means optimum conditions for my
plants. I now read the standard book on optimum conditions, the
Dupla book "The Optimum Aquarium".
Here in Germany, you can also get a brochure by another company named
Dennerle (kind of competitor to Dupla) with the title:
Algae - no problem, we defeated them long ago.
I compared the Dupla and Dennerle approach, according to *both*,
I made the following mistakes:
- not enough Fe in ground - beside some Tetra Crypto fertilizer tablets,
my ground/gravel has no laterite in it.
This prevents the plants from growing at their full
potential. I plan to use some Duplarit (see question).
- not enough Fe in water (only 0.05 ppm) - although I use Duplaplant-24 daily.
0.1 ppm should be achieved. Therefore I plan to add Duplaplant tablets
starting with the next water changes.
(I get yellow leaves on some plants, so I guess that I really don't have
- too much surface movement - removes CO2 too fast. I adjusted to have a
moderate surface movement. Both sources say that O2 should only be
introduced by plants and not by surface movement/aeriation.
In the Dennerle brochure, some additional actions are described which I also
try to follow at the moment:
- light pause at noon - currently I have 5 hours of light in the morning,
a break of 3.5 hours at noon and 5 hours of light in the afternoon.
Dupla states explicitly that this is nonsense. I do it anyway because
I think that it won't hurt- I hope... The plants are emitting fine bubbles
after some hours of light, so I guess that they are achieving photosynthesis.
- light color - I bought a special Dennerle light with gaps in the spectrum
to fight algae. Now I have this neon tube and a triton tube, both 15 W
with aluminium reflectors. (I have a 30 gallon tank.)
- In addition to reduce surface movement, Dennerle also states that O2 content
should be really low in the morning, something like 2-3 ppm (although they
use mg/l, I guess that's the same here). I currently still have about 6 mg/l
at 7 AM in the morning, I guess because the plants produce so much O2
during the day.
- more CO2 - in the Dennerle brochure, there is a table that shows what
PH values you get by injecting a certain CO2 amount at a certain KH
at 25 Celsius. They state
that 35 mg/l is ok, therefore PH 6.7 at 5 KH (that's what I have) should
be desirable. I adjusted my PH controller to 6.8 because Dupla says
6.9 is ok and I decided to go for a compromise. So CO2 should be about
20-25 mg/l now. My neon tetras seems to like the low PH - for sure.
- discard leafs with algae - I do this periodically, although I wonder
if my plants are growing them fast enough, especially the anubia.
I also introduced 4 small SAEs who are busy searching the plants for algae,
although I have the impression that they only eat young algae and not the
older, longer "black" threads that I mostly have.
It did not really get better so far, but also not worse either.
Finally my questions:
1) Is there any sense to use Duplarit-K (I think that's the name of the red,
big balls to be introduced in the ground *after* the tank is already
running) without having heating coils in the ground?
2) What do you think of the light pause? Nonsense or useful?
3) What about the O2 content? Which value do you think should the water
have in the morning? Dennerle states that most tropical fish come from
water with 1.5 to 3 mg/l anyway, Dupla seems to be a bit more careful.
Dennerle claims that algae thrive in an O2-rich environment/current,
that's what I also see.
4) I read in the Dupla book that purple-colored light promotes algae growth.
The triton looks purple, the Dennerle is more reddish. Dennerle claims
that blue is the algae-promoting color that's why they have the gaps
in the spectrum and the tube looks more reddish.
Do I better replace the Triton
with another Dennerle? The point is that the tank looks different already
with one Dennerle tube, how will it look with two reddish tubes?
What are your experiences with Triton & algae growth?
BTW, Dupla discourages the mix of different light colors at all. Any
comments on that?
Pls. feel free to give me your thoughts on all you read here, especially where
Dupla and Dennerle disagree.
Thanks a lot in advance, Andi from Munich, Germany.