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Joyce Clark Unfiltered

For "the rest of the story"

In July my family and I vacationed in California. While we were there we visited two Koi farms. Lessons learned from those visits were that we needed to beef up our filter system and we needed to add shade.  Our adult children committed to working on additional filtration. My husband and I would work on the new shade component.

Our Arizona summers with temperatures over 100 are prolific breeding grounds for algae. When the temperatures rise above 100 you can see the algae practically multiplying before your eyes. In dismay the water turns dark green and murky. We know we have fish. We just can’t see them anymore. We knew we were on the right track with our small external filter.

12. filter system running

Four barrel external filter system

It just wasn’t large enough to handle the job. The small external filter was a waste receptacle with holes drilled on the bottom of one side. It was filled with polyester batting and a small pump and hose pushed water into the receptacle. The water filtered down and exited through the holes at the bottom side of the receptacle. It works and would work well in a small pond of perhaps no more than 500 gallons. But our pond is large. It is 15’ X 25” with a depth of 2’ to 4’. It is 7,000 gallons and the little external filter was like the little engine that could. It could do the job but didn’t have enough horse power to do the job well.

8. Water to bottom

Each barrel has different media
with a layer of A/C filter pad on top

The first thing the kids did was to yep…surf the internet. They got a lot of great ideas from You Tube. Many other ponders have apparently faced the same problem and shared their ideas.  They decided on a four 55 gallon barrel system. A heavy duty submersible pump would deliver water from the bottom of the pond. It would go to the bottom of the first barrel filled with lava rock which would filter out large clumps of algae and other junk. The water would then move to the bottom of the second barrel filled with ordinary kitchen sponges. The water moves to the third barrel filled with A/C filter mats and lastly to the fourth barrel filled with polyester batting. In each barrel the water is forced to the bottom and must move up to the top of the barrel so that it can move to the next barrel in line. From the last barrel an outtake hose takes the filtered water to our little creek and into the pond proper.

10. Intake hose and pump

Intake hose and pump
at bottom of pond

11. Outtake hose

Outtake hose dumps
water into the creek






©Joyce Clark, 2013


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Our second excursion was to the Laguna Koi Ponds located at 20457 Laguna Canyon Road, Laguna Beach, CA 92651. Their hours of operation are Mon-Sat 9-5 and Sun 10-5. Their phone number is 949-484-8960 and their website is www.lagunakoi.com.

This was a very well run commercial operation. Again, we were the only visitors that morning. One of the owners, Danny, was extremely informative and answered our questions thoroughly. They had some small demonstration ponds and here are some photos.

demo pond 4demo pond 3demo pond 2demo pond 1

Laguna Koi has a humongous filtration system.  I didn’t think to get any photos but I can describe it. It was an above ground, large box, about 4’ or 5’ wide, 3’ deep and about 4’ high. In it were a series of approximately 8 to 10 medium to fine filter media. Danny said that his system handles 5,000 gallons and they usually only have to clean the filter media once a year.

little guys

Little Koi

All of his fish holding tanks were concrete and the water was very, very clear. This brings me to two major lessons learned in visiting both Koi farms. One lesson learned is that shade is essential.  We all know that California does not experience the temperatures that we do in Arizona. They also do not deal with intense sunlight 360 days a year yet they consider shade in their environment to be very important. Both Koi farms had shade over their fish holding tanks. Laguna Koi said it brings down the temperature of the water by as much as 15 degrees and the shade also inhibits the growth of algae which loves the direct sunlight that causes it to grow and multiply.

medium guys

Medium sized Koi

When we returned home we bought some shade cloth and had it assembled into a canopy measuring 18’ X 33’. We plan to put it up this week and I will share our experience as we do so. We are expecting the shade to lower our 86-90 degree surface water temperature by 10 degrees and we are hoping it will reduce the tremendous algae production we experience during July-September. It will be portable and we will take it down in the fall for reuse next summer. Stay tuned for our shade erection adventure.

big guys 2

Large Koi

The second major lesson learned is that our filtration system is inadequate. Both Koi farms had very large filtration systems with lots and lots of filtration media. We know from our experiment with our small, garbage can-sized, external filtration system that it helps to rid the pond of algae. Our visit confirmed that we are on the right track but our system is undersized and is being overwhelmed by algae. This fall we will develop a plan to add more filtration and in the winter when the fish are torpid we will build it. This, too, I will share.

big guys 1

Large Koi

There has been one more lesson learned but not by visiting the Koi farms. About a month ago we added an aerator to the pond. It is a temporary measure. We have two waterfalls that run 24/7 but on extremely hot days the oxygen levels in the pond can drop precipitously. We placed a pump in the pond, connected a piece of hose and put a spray nozzle on the end of the hose. It adds additional oxygen to the pond water. One day we had to turn it off. By that afternoon I saw one of the 8”-10” goldfish coming to the surface and desperately gulping for air. The fish usually stay at the very bottom of the pond during the day. I freaked out, restarted the aerator and let it run all night. Usually I run it during daylight hours only. I expected to see a dead fish on the surface the next morning. To my delight he did not die and can be seen swimming and feeding with the pack. We learned that our instinct was correct and the extra oxygenating is helping our fish to combat the stress of an Arizona summer.