I have an 80-foot-long pool for water lilies and other aquatic plants. In the past the pool was dyed black to make it a reflecting pool. The black dye also covered up the algae and murky water. This year I focused on water quality so that I could introduce fish to make the pool more interesting. It has been a fun and educational experiment.

 

There are so many chemicals on the market that it is hard to decide which to use. I selected three. I used a name brand algicide, beneficial bacteria product and barley extract. I followed the instructions for dosage and frequency of the liquid applications. I have a UV light in the filter line that I unplugged for a couple days every time I introduced more beneficial bacteria. Not wanting to make a big investment in fish for this experiment, I purchased some small goldfish and then some 3-inch shubunkins. I then added small amounts of salt for the health of the fish. 

 

Results: My shallow 9,000 gallon pool is in full sun and algae started to grow immediately when the pool was filled in April. It took a few weeks for the water treatments to get that under control and yield clear and clean-looking water. The fish seemed to thrive except on really hot days. I added a thermometer that showed water temperatures exceeding 90 degrees at times.  70s is optimal, 80s is pushing it and 90 degree temperatures can be fatal to fish. I also invested in a dissolved oxygen meter because this is a still pool for the water lilies.   There is no aeration and I suspected that the oxygen levels might be low despite throwing in a dozen hornworts at the beginning of the season. Sure enough, oxygen levels were sufficient during the day when the plants were photosynthesizing but dropped down to almost lethal levels at night. So I added a battery operated aerator to help remedy this.

 

The bottom line is that the experiment with treating the water was pretty successful and I can now enjoy seeing the fish swimming around. The downside is that I also see all the dead plant material that drops to the bottom of the pool. I either need a better filtration system that can move that material out of the pool or I might invest in a pool vacuum cleaner to suck it out each morning. Anybody else have better ideas on how to either remove or hide the layer of material that invariably falls to the bottom of a formal lily pool?