What can you do with this? Fish Fungus

Last year, one of the fish developed a fungal infection:

We don't care much about this particular one as it was a 12 cent feeder fish but the same pond has other fish.  The koi, for example, are quite valuable. If we did nothing, this one might infect the rest.  So we needed PIMAFIX, but how much?
More below.

That's not too detailed a picture. You can give them this one following or let them search it out on the Interwebs. They need to find the text at the bottom of the bottle that describes the dosage proportions.

Next comes the question, "How big is the pond?" "Well, I don't really know. Certainly not the number of gallons or liters. But it is a pretty decent circle.

The sides are pretty steep. I guess we can assume the general shape of a cylinder. Maybe drop a percentage off the total?

So, how to measure? I didn't bring my math teacher's 100 meter tape so I walked around it and counted steps. One lap around the pond took me 65 steps, and my steps are pretty close to one yard long. I walked very close to the edges and the side walls are steep. When I drained the pond years ago to get out the boat motor someone had thrown in (don't ask) the bottom was roughly a flat bowl shape. The depth is 6 – 8 feet, depending on the weather.

I've got the blue bottle at school:
Bottle of PIMAFIX
Net 16 fl. Oz (473ml)
Treats up to 2,400 US Gallons (9.085L)
Add 2 teaspoonfuls (10ml) for every 50 US Gallons (190L) or 1/4 cup (60ml)for every 300 US Gallons (1,135L) of water


Take it away!  Give as much or as little as your kids can handle or need.  Good Luck.

p.s. The fish didn't make it.  But the other one that developed it did, and the one that developed the same infection this year also seems to be doing well.  It's a pretty common situation whenever the slimecoat is scraped off or damaged.  Breeding frenzy and the rubbing that results from it can be a cause.  This year's fish has a large cut, probably an owl or other bird, but the cut and the fungal infection are both improving.