Sick Koi

[Blueiz]

well the only way to get ammonia down permanently would be to get some better filtration.

Id have to disagree here.. The cycle has to complete before his ammonia will be to zero. Even if there was no filter on the tank, if the cycle was complete, there would be zero ammonia...

Add aereation to the water, if possible get the temp down, IMO 74 degrees is not to hot for the fish so long as there is aereation of the water to accomidate this increased temp ( surely the temp of an outdoor pons gets 74+ in the summer). As others have said, do water changes to get the ammonia down, and keep it down to at least .25 or below. Same goes for the inevitable nitrite spike that will follow. Change as much water as necessary. For next winter, you may want to see about getting something a bit larger to house these guys in. Or in the interim invest in a large rubbermade tub to seperate the fish. As your tank is OS, would be a good thing to do at least 50 prcent water changes twice a week after the cycle completes, and to feed very lightly over the course of the temp housing.

Blue

 

[Reddog80p]

Next year you can actually leave the gf/koi in the pond outside. It's below 0 here and my gf's and koi are fine outside all you need is a floating heater to keep the ice open to alllow gas exchange and a bubbler about halfway down, so you don't distrub the warmer water on the bottom. As far as keeping them in a aquarium I totally agree with Blueiz's advice. Anytime you have pond fish do not feed when the water temp is under 50 degress, you could kill the fish they have trouble digesting food at that low of temperature, my fish have not eaten for 2 months +, and are all alive and swimming under 3 inches of ice.