Be very careful!

My newly enlarged pond did the same thing several weeks ago....crystal clear to
the bottom, (35" deep) Then the fish started dieing. I lost 7 over about 10
days. 2.5" to 15" Koi. I have learned more about pond water chemistry in the
last 2 weeks than I've know in my ponding experience of the last 4 years.

It turns out my problem was a pH crash due to acid rain and not enough KH
hardness to buffer the rain.

I would strongly recomend checking your pH and KH. If pH is below 6, you need
to start adding baking soda today. You can read more about pH crashes and
remedies at www.koivet.com

http://www.koivet.com/html/articles/...icle_id=206&na
me=Newest%20Articles

If you do need to bring it up, your KH will be low also. Check it and bring it
up slowly at least to 110 or so.

A good formula for baking soda is (a * b)/5000 = bs
Where
a = pond in gallons
b = amount of kh increase for dosage
bs = ozs of baking soda
Ex. (1400*10)/5000 = 2.8 oz A 1400 gallon pond and 10 ppm KH rise.

Experts recommend 10 to 20 ppm KH rise daily or more quickly if your fish are
dieing.

Didn't mean to rain on your parade, but if this information saves you from
having to go through what I did, then it is worth it.

Bill