I have to say that this years temps, in So Cal, have also been much cooler than usuall. On fish that we purchased last October as 2 year olds, we have seen an average of 3 inch growth. On our koi over 24" this season our average growth so far is right around 1.5 inches. We have been able to add some weight to all of them, but nothing extrodinary. Our ponds have all been in great shape as far as filtration. We had 1 koi bump her mouth and had to give her 2 silver bullets. She is 100% recovered with no visable scaring. Maintenance is very easy. Husband wants to distroy turtle pond and 2000 gallon pond and make one larger pond for koi. Turtles all went to a new home so it looks like he will be starting his new profect this winter... Great more mess... new landscaping... dirt everywhere.... On the bright side more room for New Koi