Neale, regarding hardening the goldfishs water, am I essentially reintroducing trace elements and minerals?
Here’s a product I located: Aqueon – Goldfish Water Renewal – 4 oz. Replace your goldfish aquarium water’s trace elements with this simple formula. These essential compounds are necessary for fish and plant survival and become depleted over time. Special liquid restores these minerals and promotes health, color and vigor in your goldfish. Thanks again! Lisa