Update on the Koi

[king2005]

All I get is the tanks are too small, the fish will die, give them away, build a pond(in the middle of -30 winter)

You can keep goldfish in -30C. Also in this area it doesn't hit or stay at -30C often/long. Where I'm from it was an avg of -30C & for 1-2 months it was -40C with FEET of snow & the goldfish always lived just fine. There was a heater in the pond & they were fed every 2nd day. It was awesome being bundled up & feeding the goldfish. Not so much when they splashed water.. that was COLD after a few seconds!

Only one person on one forum gave me advice that I could do. Empty the tank 75% and add in new water, reduce the amount I feed them(I was over feeding them) and so on.

75%??!! Whoever told you that needs a swift kick in the pants!! Never change more then 25% of your tank water or all the good bacteria can die, or it wont be able to reproduce fast enough to help the fish out.. So doing 75% water changes is terribly unhealthy for all fish (pond or tank).

When doing water changes its important to use a chemical to remove chlorine from the tap water, as chlorine will burn the fish & weaken/kill the good bacteria.

Pellet food is better then flakes.. Flakes sink so fast that they create waste faster.. pellets float & give the fish enough time to eat it.. This goes for all fishies.

koi & comets are not tank fish, ever. And whats sold as a Common Pleco, needs a min of 50gallons, but is happier in +75gallons. Common Plecos grow to about +12inches long.