Gasping koi, especially the larger one(s), is usually O2. Did you have the
pet store test your water while you were there? A fish with fried gills or
parasitic invasion of the gills, could be doing the same thing regardless
of dissolved oxygen in the water. ~ jan


See my ponds and filter design:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
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