I am sooooooooooo confused! What does all this mean? In ordinary English
language?

Not just your response GD, but the entire thread has me lost.

--
_______________________________________
"The difference between 'involvement' and 'commitment' is
like an eggs-and-ham breakfast:
The chicken was 'involved' - the pig was 'committed'."

http://community.webshots.com/user/godwino

"GD" wrote in message
...
~ jan wrote:

GD replies to Sam's post on algae:

Although you are correct , you leave out something that is very
important regarding algae: it is well-documented that most algal
blooms are caused by excessive phosphorus.

I agree, and rarely does most tap water (city treated) have high amounts
of
phosphorus. It not just understanding algae, it's understanding the
difference between the different types of algae and their relationships
with each other. See: Green Water at
http://www.koiclubsandiego.org/H2oQual.html

A single dose of tap water will not support an algal bloom. Repeated
topping off ponds without partial water changes results in increased
concentrations of chemicals that do not escape as gases, including
phosphorus.

The theory put forward at the website
http: //www.koiclubsandiego.org/H2oQual.html
(heterotrophic bacteria producing antibiotics that kill algae) is
questionable. If such chemicals are produced, it is possible that
bluegreen algae would be susceptible (certain antibiotics have been
used to control bluegreen algae). However, in many cases, algal
blooms are not caused by bluegreens, but green or other groups of
algae that are not affected by antibiotics (they are eurkaryotic
organisms, rather than prokaryotic, on which antibiotics may work).
The aquaculture industry uses beneficial bacteria in intensive fish
culture to control excess nutrients and algae. It is a practice of
competitive exclusion: make conditions more conducive to beneficial
bacteria, and they will outcompete any algae for nutrients, thereby
controlling green water. Although not always the case, in most
instances it always comes back to the same thing: too much
phosphorus, not enough competition for the algae.

Flow contributes to mixing of nutrients, surely. However, even
without a current, nutrients and minerals will enter the water column
from sediments, unless a physical or chemical barrier exists.

Yea, it's called diffusion.

Technically, it leaches. Once it has leached, it then diffuses. I
know, I know, splitting hairs. But...an interesting application with
some benefits comes from this. In research tanks, where algal growth
may compromise submersed aquatic plant growth, controlled leaching
reduces nutrient loads and avert blooms. Control is achieved by
fertilizing and soaking in water contained separate from the tank,
generally a bucket. Wait 24 hours, change the water, and replace with
fresh water. Wait another 24 hours. Much of the excess fertilizer
leaches into the bucket water. Place the plants back in the tank, or
pond. Although some nutrients will continue to leach into the water
from the substrate, the load is much reduced and less likely to
support a bloom. This works with soil and clay substrates. It does
not work well with sand, and I have not tested with gravel.

You'll notice that around fountains there
usually isn't any algae growing.

On the other hand, in ponds with already low concentrations of carbon
(as might occur with a veggie filter filled with submersed plants),
aeration will increase carbon concentrations. This is why algae and
plants do best near waterfalls and fountains in some ponds.

Course this could also be just because the koi can't reach it to remove
it,
so it just *seems* like that is where the best growth is. At least that's
my theory regarding my ponds. ;o) ~ jan

Good theory. And likely fact. Many fishless ponds, especially those
well-stocked with submersed plants, also sport greater algal/plant
growth around fountains and falls, due to input of atmospheric carbon
dioxide.


See my ponds and filter design:
http://users.owt.com/jjspond/

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website