I recently discovered an old cement pond on my property and I was
hoping to get a few questions answered:
1. How do I calculate the size of the pond, in gallons? Its an odd
shape, so I don't know if the typical formulas apply. Its a kidney
bean shape with sloping sides. Its about 10 feet long by 4 feet wide
by 4 feet deep. But again with the sloping walls, I have no idea if
my pond is 400 gallons, or 1400 gallons.
Taking into account your sloping sides my guessimate would be a
conservative 1,000 gallons. Do you have, or are you familar with, test
kits? The salt calculator RTB mentioned is the most accurate sans metering
the water in, but you'd need a salt test kit. If you're willing to pay for
it, pick up ammonia, nitrite, pH, & KH tests also if you don't have them.
;o)
2. I (probably like many people given the time of year and change in
temperature) am battling algae. Its not the string kind, rather the
pea soup kind, so I can't see the rocks at the bottom anymore, and I
can't see the fish. 
I have heard that the quickest and easiest
fix for this is to pour some beer in the pond each week - does anyone
have any experience with this, and if it works, how much should I put
in each week?
3. I have goldfish and now recently added koi too.
With problem number 2 one should not have done number 3 above, as it adds
to number 2. Do you have a filter? If so what kind? Tell us everything you
know about it, gph, in or out of the pond, size in gallons, filter media.
How are you aerating the water?
You have pea soup because you don't have enough filtration in ratio to
fish. How many fish are there now? If you have no filtration, and no plans
of putting any in and you don't want to miss with test kits, etc. I'd
recommend removing the koi and reducing the goldfish number to no more than
4. They will have babies, those will have to be removed on occassion.
K30a, of course, covers all this and more in her green water cures. ~ jan
See my ponds and filter design:
http://users.owt.com/jjspond/
~Keep 'em Wet!~
Tri-Cities WA Zone 7a
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