Butterfly Koi Eye Color Difference and Bottom Resting

6-inch butterfly koi has one solid black eye with silver dot, other solid silver with black dot. Sometimes rests motionless on bottom. Tank: 35-gal with 1" comet, 7" shubunkin, small pleco. pH 7.4, no ammonia.

Eye Color

Koi can have different colored eyes; usually not a concern. Photo would confirm.

Bottom Resting

Can indicate boredom, poor water quality, cold, or illness. Tank is overcrowded (35 gal for 7" + 1" + pleco). Upgrade to 55-gal soon. Test tap water pH/ammonia—water changes may worsen if tap is the issue.

Pleco Risk

Small plecos sometimes suck on sleeping goldfish/koi fins. Check for damage.

Feeding

Quality goldfish/koi food (Tetra flakes, Hikari). Pleco: algae wafers.