New city pond, small garden

I'm about to build a small pond and waterfall. The waterfall will
begin about 15 feet from the pond, with about a 4' height above the
pond surface. The pond will be approximately 6' x 3' x 2'deep (all
just theory now; please advise). I could have 2 smaller ponds
connected by a "canal" or deep channel, or another short waterfall.
Some fish would be fine, at the very least to eat mosquitos, though my
daughter is urging me to have koi. I live in the city, and my garden
isn't large, so everything is compact. There are definitely raccoons
here in San Francisco, as well as heron, skunks, mosquitos, etc.

So, the questions:

1) I understand that if I have a 2' drop, the raccoons won't go into
the water for fish. How will that work if I have a narrow channel, or
a "canal"? Does anyone have experience with this? I'm imagining the
raccoons wedging themselves between the sides of the canal and
lowering themselves in. Is there a minimum width I need to keep
raccoons out? (I don't want to install the electric anti-raccoon
fence/wire--too unsightly.)

2) Also about raccoons: If I have a 2 or 3 foot deep pond, with some
shallower (6"-18") ledges for plants in water pots to sit on, won't
the raccoons stand on these ledges to fish?

3) I want to install a do-it-myself filter. The waterfall may provide a
fair amount of filtering, since I plan for plants along the length. I
would like the waterfall to be quiet and barely trickle; will that
provide enough gpm for the filtering process, or do I need it to move
faster? Will I need a canister filled with gravel or filter material
as well. Roughly what volume canister should I use? Should the
canister be in the pond, or at the top of the waterfall, or can I put
it somewhere in between, at say, 2' height above the pond? If it were
in between, can I put the pump midway between the pond and the
canister, thus forcing the water through it, then up to the top of the
waterfall?

4) What's the minimum size pond for 2 koi? Frogs? Turtle? Snake?
Are these animals feasible in a small pond?

I've got a rough hole dug, and the path of the waterfall laid out.
I'm excited to get it it! Many thanks in advance for any responses.

--rgesh

Do NOT get koi for that size of a pond. They really won't do well. In your
area I would recommend comets, shubunkin or even fantail gold fish but I
would start with feeder fish until you get the kinks out of the system
(feeder fish are plain goldfish they sell to feed to other animals - I
'rescued' 50 when I first made my pond to keep down mosquitoes, 25 died in a
couple of days - I still have one of them 10 years later and MANY of their
offspring). The fancy goldfish come in very spectacular colors and are just
as pretty as koi. Regular koi will make lots of waste, dirty your pond by
rooting in the plants and in general be difficult to keep. Butterfly koi
are better mannered but still get very large and need more room than what
you are planning. Tadpoles would be nice but they will need a way of
resting on solid ground once they are frogs as will the turtle. The snake
is going to eat your fish and probably won't stick around.

http://animal-world.com/encyclo/fres...inGoldfish.php
http://www.ciwga.org/newsletter/2002-08/feature.html

With raccoons around you will want to make the sides of your pond go
straight down as you said. Do not put in 6" ledges for plants. I cannot
emphasize this enough. If you are concerned about having a place for plants
just get some plastic crates and turn them upside down to serve as shelves
(but put them enough away from the edge that raccoons can't use them or tear
the plants up. If you get the type that are used for stackable storage then
one side is shorter than the others and this give fish a 'cave' to hide in
which they really like. The plants you put on the crate to hold it down
will keep it from being unpleasant to the eye (and algae will cover it as
well). The raccoons are not going to "lower" themselves down using the
sides of the canal. Basically if the sides go straight down and the water
is deeper than they can stand in with their heads above water then they
won't go in your pond.

What I use as my bio filter and as a source of water to my upper pond and
falls is a large bucket (5-10 gallon) with a water fall pump in it. This is
filled with lava rock. The lava rock acts as surface area for the good
micro-organisms that break down fish waste and it filters the water a bit
before it goes into the waterfall pump. I rinse this out maybe once a year
with pond water. Some people use peagravel and a crate for this purpose. I
like the lava rock because it is extremely light (floats in fact) and it has
more surface area for the good stuff to grow on.

http://animal-world.com/encyclo/fres...inGoldfish.php


"Rob" wrote in message
om...
I'm about to build a small pond and waterfall. The waterfall will
begin about 15 feet from the pond, with about a 4' height above the
pond surface. The pond will be approximately 6' x 3' x 2'deep (all
just theory now; please advise). I could have 2 smaller ponds
connected by a "canal" or deep channel, or another short waterfall.
Some fish would be fine, at the very least to eat mosquitos, though my
daughter is urging me to have koi. I live in the city, and my garden
isn't large, so everything is compact. There are definitely raccoons
here in San Francisco, as well as heron, skunks, mosquitos, etc.

So, the questions:

1) I understand that if I have a 2' drop, the raccoons won't go into
the water for fish. How will that work if I have a narrow channel, or
a "canal"? Does anyone have experience with this? I'm imagining the
raccoons wedging themselves between the sides of the canal and
lowering themselves in. Is there a minimum width I need to keep
raccoons out? (I don't want to install the electric anti-raccoon
fence/wire--too unsightly.)

2) Also about raccoons: If I have a 2 or 3 foot deep pond, with some
shallower (6"-18") ledges for plants in water pots to sit on, won't
the raccoons stand on these ledges to fish?

3) I want to install a do-it-myself filter. The waterfall may provide a
fair amount of filtering, since I plan for plants along the length. I
would like the waterfall to be quiet and barely trickle; will that
provide enough gpm for the filtering process, or do I need it to move
faster? Will I need a canister filled with gravel or filter material
as well. Roughly what volume canister should I use? Should the
canister be in the pond, or at the top of the waterfall, or can I put
it somewhere in between, at say, 2' height above the pond? If it were
in between, can I put the pump midway between the pond and the
canister, thus forcing the water through it, then up to the top of the
waterfall?

4) What's the minimum size pond for 2 koi? Frogs? Turtle? Snake?
Are these animals feasible in a small pond?

I've got a rough hole dug, and the path of the waterfall laid out.
I'm excited to get it it! Many thanks in advance for any responses.

--rgesh