Robert's Home Renovation: Cleaning the Fish Pond

I had last cleaned the fish pond in 2013, and waiting three years was a mistake. The water in the pond became dark, evil looking and choked with a red algae that I had never seen before. The water lilies were thriving in that environment but I knew that the algal bloom would not be good for the fish because it would deprive them of oxygen. I was jogged into action during a visit by Miles, who knows about these things, who told me that the pond needed cleaning urgently.

Before cleaning. Note traces of red algae.

I planned to clean scrub the walls of the pond the traditional and difficult way of using a scrubbing brush but Miles insisted that he help me by using his industrial-grade high pressure spray.

On Saturday 1 April is began siphoning the pond water using two garden hoses. Late that afternoon the pond had only about one foot of water remaining and I phoned Miles to tell him that I would be cleaning the pond the next day, ready to go it alone of he could not help me on such short notice. To his credit, he arrived that evening with his wife Cindy, and young son Owen and was able to get to work immediately because by the time they arrived the pond was empty, the surviving fish were safely in a large container, and the four buckets with overgrown lilies were also out of the pond. He worked with his pressure cleaner until Dark.

Bucketing the last of the pond water had been only one step above bucketing sewage. The brew was dark, and evil smelling. Four of the 15 fish were not able to survive the ordeal and died. It is an ordeal for the fish because in order to escape my clutches they burrow into the soft mud and I am forced to filter all water through a large sieve in order to capture the fish.

Water level down to a foot. Note reddish tinge of evil brew.

Miles at work, overseen by his inseparable dog

Industrial pressure cleaner powered by petrol engine

On Sunday morning Miles returned and finished cleaning the pond, then cleaned the waterfall, then for good measure cleaned the entire back patio with its granite surface.

The next day I did a lot of pruning of the water lilies then returned only 3 of the four pots to the pond. Brenda took away most of the water lilies to give to a friend and she told me that her car smelled like a swamp as she and Coral transported them to their friend's place.

I inspected the pond while it was empty and noted some cracks and one large cavity in the lining. This is not as serious as it sounds because the sides of the pond is formed by heavy and thick blocks of granite stone, so there is a lot of depth to the walls. Nevertheless I spent several hours "pointing" the pond with mortar, then spent a few hours the following day doing more serious repair work on the waterfall, which I knew had been leaking because I was losing water whenever I ran the waterfall.

This was the first cement repair of the system since I had built it 36 years earlier, in 1981.

I let the cement cure for about two days then filled up the pond, emptying 250 ml of conditioner into it. The conditioner would neutralize the effect of the fresh mortar, among other things.

Day later I put in the three water lilly pots, filled up the pond, launched the 11 fish, and once again 'God is in his heaven and all's right with the world', using the words of Robert Browning.

I recorded "before" and "after" readings of the water meter and now know that the fish pond holds 2725 liters (720 gallons).