Base to what Mr. Kiky experiencing of K1, then I decided to use only K1 as my filter media. I put about 250 litre for about 1000 litre filter chamber or about 25% of the filter chamber volume. The K1 just perfectly moving upside down and I just filled kois to my new pond 3 days ago.
Beside K1, I added 5 trays of Bakki Showers.
I bought the K1 from Mr. Bohan Jauwan (Oriental Koi) for about Rp. 10 jt for 11 bags or buy 10 get one for free.
This is the link to my new pond :
My clubbing style koi pond