As water temp increases it's ability to hold disolved oxygen decreases. Your
best bet is to some how cool the water off. If there's a super hot day dump
some ice in the water. 60-70 gallons wont be hard to cool with ice. Shade
would be the easiest.

"jammer" wrote in message
...
Besides plants, is an air stone the only way to increase the oxygen?
This is the first full summer for the pond and it is HOT. Is there a
danger zone temp where water HAS to be cooled or air MUST be supplied?
I don't have electicity out there yet. I could run the trouble light
out there and throw in a small aquarium stone i have, but it would
have to be during the day when no one else was home.

This is a 60-70 gallon job and I have 2- 4 inch goldfish and about 30
toadlets.

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