new to koi and need HELP!!
I just bought a house that has a small (about 460 gallon) established koi pond with a few larger koi (about 8 inches) and a lot of smaller koi (3-4 inches). When we moved in the pond was a yucky sludgy, green mess and I have been working for about a month to get the water back to a semi-clear state. I have been doing water changes of about 120 gallons every week as well as treating the water with Algaefix according to the directions. I clean the filter and pump the day after I treat with algaefix and this has been working. I can now see about 15 inches down into the pond. My problem is that when I did a water change on Saturday, the koi were active as they usually are during the change. I went to feed them the next morning and they would not come up to eat. This continued on into Monday and now it's Tuesday and no signs of koi at all. I did another water change yesterday in hopes of seeing them, but I got nervous and filled the pond back up after about 300 gallons (treating for chlorine when I change). While I was doing that, I found a fin embedded in the algae on the sides of the pond. I have no idea how old the fin is, but it's large. I can't see my koi so I have no idea if they are dead or just bottom feeding or spawning...
Any ideas on what's going on--why I haven't seen any fish for days? I have been to a lot of aquarium stores in the area pressing for information and I seem to get a lot of "you need to buy this to fix your problem..." I hope that they are okay--I've gotten attached in a month and want them to be okay. I just don't know what to do!!