"Robin" wrote in message
news:nq2qe.40919$xm3.27198@attbi_s21...
My aunt has a 1250 gallon pond with a skimmer and UV light. Apparently her
UV light went bad and her pond turned into pea soup. All of her fish
died, I suspect from lack of oxygen; but they assumed it was the algae.
My well meaning but misguided uncle poured a gallon of bleach in to kill
off the algae (at least he took the plants out first.) It worked, not a
hint of algae in the pond, LOL. What will have to be done to make this
pond fish safe again? Will it have to be completely drained and scrubbed?
Would a couple of near total drainings and refills followed by
dechlorinator work? Ideas?

I suspect a single near draining of the water will be enough, combined with
a few days of running whatever water circulation to let the remaining
chlorine evaporate out. and of course some dechlorinator would be enough.
You didn't say if this was liquid chlorine, like the kind used in pools, or
chlorine bleach for laundry use.

A gal of pool chlorine is a higher concentration, it might take a few
drain/refill cycles. The biggest thing to remember is time, aeration and
water circulation to let the chlorine evaporate out.