Our Koi are dying and I need help.They have not started to eat yet - pond still too cold. We have lost two so far and two are in the bathtub...sunk to the bottom on their sides. I tried peas but they aren't eating. Our oldest Koi has a bit of what looks like a fungus. Our pond is big.... haven't checked the condition of the water - have no clue what that should be. we are newbies at this. we have had our Koi for 3 years and this is the first time this has happened. they winter in the pond and previously have been ok. Help.