Help. This is something new to me.

[ZEROPILOT]

Don't bother with a test kit they aren't worth the money that the packaging costs. You've done what you should which is a partial water change (although I would have done more than 200 gallons) and increasing the water agitation. You're in Florida and the weather has been hot it sounds like there has been a build-up of nutrients in the water and that along with the extra water agitation is causing some frothing and the bubbles.

I have to ad chlorine and Cloramine remover as I ad water. Or mix it first in a 55 gallon drum. Then release it into the pond. Either way is difficult and not at all ideal.

 

[ZEROPILOT]

The fish swam up to greet me this morning and are acting "happier".
The water also looks better.
I think the crisis is behind me. But the cause is still a mystery.

 

[ZEROPILOT]

Yep.
Today it's as if nothing ever happened.
Fish are normal.
Water is normal and no fish losses.
Thank you all.

 

[poconojoe]

I have a small digital water meter device that connects to the end of my garden hose. I add my dechlorinizer to the water as its rushing into the pond. The meter counts the gallons, so no guessing on how much dechlorinizer to add. The meter was a mere $10-$15 dollars on Amazon.

 

[ZEROPILOT]

I have a small digital water meter device that connects to the end of my garden hose. I add my dechlorinizer to the water as its rushing into the pond. The meter counts the gallons, so no guessing on how much dechlorinizer to add. The meter was a mere $10-$15 dollars on Amazon.

I use at least 100 times too much I'm sure. The way I pour it in the pond.