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Bacteria, algae, and N:P
I have been poking through some Aquatic Microbiology mag's I saw in the
reference library and it seems there are many, many species of algicial
bacteria. Many species attack cyano's(old= blue green algae) and a few other
forms of algae but do not attack the Greens often. At least there's no
supporting evidence that I've found so far. I intend to look further into
this issue though. There's been some work but there's much yet to be done.
I have felt that the soil/substrate plays the most critical role in both
nutrients and bacterial cycling of these nutrients but this algicial
behavior with cyano's seems relevant to our tanks and could be a solution
even without using antibiotics. Perhaps there are others than can target
specific algae. In many tanks, we find algae cannot exist/persist/compete
even though the nutrient are available to them. Bacterial actions/presence
may be the key.
I'll see what I can dig up out of the substrate later:)
Also, I found compelling evidence for not letting your N:P ratio fall below
16:1 for aquatic plants. Neat stuff. So if you have a NO3 of 5ppm your P
would/should not fall below 0.3ppm or so. The optimum seemed to be about
10:1 or so of the studies I looked at. So .5ppm for a NO3 of 5ppm. This
might explain why at 1.2 ppm of P and my higher NO3(10-15ppm or so) that my
plants did well. Steve Dixon did this lower NO3 at 2-5ppm with a pulse of P
to about .2ppm or so. He had good results and so did I. We both had a
similarly close ratio. I have been doing to the lower end ratios these
days(pulses of P with lower NO3 2-5ppm or so) I want to find out how far
this ratio can go. What is the upper limit with a set of CO2 levels/light
values and excess Fe, K+ and trace elements without algae build up?
I'll need to get a new probe for my tank so I'll be doing this once it
arrives.
Regards,
Tom Barr