[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Algae went away

A few months ago I set up a new tank. The substrate is fairly fine gravel
with a small amount of soil mixed into the bottom 1/3 of the substrate. I
planted well from the beginning and added algae eaters after a couple of
weeks as soon as I had a decent crop of algae on the glass. I also added
PMDD fertilizer from the beginning in an amount that I felt was proportional
to the plant mass in the tank. I even added a small amount of flake food to
the tank to supply phosphate. After a couple of months I added a few fish.

Growth was very good at first but there were signs of nutrients deficiencies
on some of the plants. I was never sure which nutrients if any were missing
though so I did nothing to correct it. In fact, I decided to just continue
with the normal routine that has worked for me in established tanks. 20%
water changes per week, fish food daily, CO2, PMDD weekly, and lighting at
10 hours per day. I also never cleaned the glass in the tank or removed any
debris from the tank.

The tank had a real tendency to develope green water and I believe that once
green water is established it scatters the light to such a degree that
plants near the bottom of the tank can't get enough light. So I intervened
at this point and  treated the water with a floculant. I felt I had to
repeat this two more times. The water was never really clear though and you
could see the green water just hanging around waiting for another chance.

After about 4 months the tank was still somewhat murky but looked fairly OK.
Then in a period of less than a week the water turned crystal clear. There
is still a little bit of algae on the glass which the bristle nose pecos
appreciate. I really like the look of the tank now. I would probably have to
do something like excessive feeding to create an algae problem now.

Now I know that the algae disappearing like this is not uncommon but I
really have no idea why it happens. I do not believe that it is a result of
limiting a particular nutrient as I supplied all nutrients all the time, in
the form of PMDD, water changes and fish food.

Is it the bacteria colony maturing in the tank? Do certain bacteria or
infusoria that eat algae become dominant and consume all the algae? Is it
something the plants put in the water? Does it have to do with the
developement of the plant root systems? Is it the action of bacteria in the
substrate that makes nutrients more available to the plants or can it be
that the presence of natural chelators in the water column like humic acids
that somehow inhibits the algae and provides nutrients to the plants? All of
the above?