How to create a 'hard water' koi pond ?

[dimashp]

Dear all,

This is a rather weird question, i have 4.5 tonnes pond. It is actually made to quarantine my koi. However, there will be a koi show in Indonesia in about 1 month 3 weeks time. I'm thinking to create a 'finishing' pond, to prepare my koi (actually just my Sanke).

My Sanke is still kinda orange in colour (near to 50 cm), Not really orange though...and his hi on his head is red...so...this is not a sign of 'low quality' hi right ? and hi spreads evenly...kiwa is good...sumi is still developing but already shows its existence...body is superb...I'm thinking to let him inside my mud pond for 2-3 weeks...and in the meantime, what should i do to create a hard water pond ?

Thanks

Dimas