Pond cleaning

I drained about one third of the water out of the pond today. Partially because it has finally not rained a ton for the past couple of days so I needed to water the tomatoes, and transplant some of them, so I used the pond water. The photo is of the lower pool with most of the water out, the fish were kind of worried but what can you do, I couldn't explain it to them. I refilled the pond with half rain water, half tap water (dechlorinated). I figure since the rain water is too acid and the tap water is too base they will even themselves out. And it's good to change the water regularly, I always take it out with the pump, which sucks it from the bottom, and hopefully gets all of the toxic fish pee out.