With regard to the pH, I would really be interested in seeing what your KH level is. The KH is the buffer level to control swings in the pH, and as most of us that have ponds, have water that has been through limestone deposits, thus the KH can be nice and high, the pH will be close to 8.3. There are a few that I know that have water that is basically devoid of any KH buffering capacity and have to add baking soda to get a resonable KH value, and there pH will be about 8.3, again because of the carbon dioxide/bicarboniate/carbonate buffer system. That system is not the only buffer system, but the most common. If the water is not adequately buffered, by a KH of over 80ppm/5 drops or higher with higher being better, pH crashes are a real possibility and will cause death to the filter system and potentially to the fish. Since you have not posted a KH, I assume you have not gotten the kit, and would highly recommend you get it and sooner is better.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard