Koi -vs- Goldfish -vs- Minnows/Mosquitofish


When considering the best balancing of your pond, one should be aware of the mass (weight) of the fish involved and their symbiotic* relationship within ecosystem of your pond; the nitrogen cycle (refer to blog); more fish mass = more need for proper Biological filtration (refer to blog) and/or resulting plant growth. Remember that algae is a plant and thus if your fish load is heavy then there is more likely for your water-garden to experience a heavy algae “BOOM” growth -aka-“Going Green” (refer to blog).


For example, even a single large koi could off-set your pond balance and the result may be an unhealthy load on the pond, ….and a heavy algae growth as a result.

The Load effect based on weight of fish is as follows;

One adult mature Koi                     =        at least 60-70 goldfish  or                    =        more than 120 -140 minnows !! 


Another problem with Koi is that they can be voracious** eaters, eating up all the beneficial plants such as Anacharis ( refer to blog post on Anacharis). A large heathy growth of Anacharis and other aquatic plants would help to balance and keep your Pond looking clear and beautiful (Balanced).


*sym·bi·o·sis /ˌsimbīˈōsəs,ˌsimbēˈōsəs/ noun BIOLOGY; interaction between two different organisms living in close physical association, typically to the advantage of both.

**vo·ra·cious /vəˈrāSHəs/ adjective; wanting or devouring great quantities of food. “he had a voracious appetite”


How many Koi for your pond?

A simple question with a not-so-simple answer. This is because there are many factors to determine a good population for your koi*pond. Now, some rules of thumb are “floated” out there based on gallons of the water of the pond. The “answers” you will find for grown, developed koi will range from “basic rule…250 gallons per koi” up to “…1,000 gallon + per koi”. Please note: if you get small koi, they WILL grow to become a BIG KOI before you know it ! It is naïve to think that the gallon amount of water alone is all there is to creating a heathy environment for your koi to thrive in. There are a multitude of variables that will impact the needs in creating a heathy environment for your fish. A biological ecosystem – yes that is what you are creating- has a multitude of factors seen and even unseen. Good Filtration and circulation are essential to this equation. Furthermore, there are many other considerations that come into play, such as temperature, climate, depth of the pond, aeration, etc….

THE BEST ADVICE IS TO STOCK THE POND CONSERVATIVELY AND TO MAKE A WELL ADVISED DETERMINATION BASED ON YOUR INDIVIDUAL POND. Sadly, most novice koi keepers think too BIG in terms of their ponds ability to support and consequently learn the hard way that they have overstocked; ammonia spikes, fighting disease, overcrowding …sadly losing fish by death till they finally determine just how many koi their pond can support. Thus, our advice is “go slowly”, collect over time and avoid overwhelming your pond.


*Note; Other breeds of fish such as goldfish or minnows are much smaller and thus have much smaller impact per fish on the ecosystem and thus you can stock a vastly larger number of fish. We recommend smaller fish breeds for any shallow pond (under 24”deep) or under 2,500 gallons.


This biological, up-flow filter was developed years ago using stratospheres of grated rounded stone and silica to create the best biological filter you can find for your pond. The ease of cleaning using a volume of air to “forward-wash” is superior to any backwash procedures we have ever come across, and this is the key to any successful filtration system. These filters have stood the test of time, first installed in the 1960s, some of which are still running and in service! They are a custom made system that does NOT EVER need to have the media changed or removed for service and maintenance!

Heres to you having a healthy, balanced, crystal clear pond with your Z-Bio-Filter!

Anacharis Bunch How To

Anacharis is a very helpful plant that helps balance the water in a pond. The video attached is our method of bunching Anacharis to get it ready for sale and for planting.




The Pond Company: Bear Cub in Pond on Camera

This bear cub was caught on camera at The Pond Company client’s pond. “Helping with trimming the water lilies”

Koi Fish Rescue From Wolsey Fire Malibu

Fish thriving well from our save back in November during the Wolsey Fire in Malibu. The Pond Company saved fish from the burned home of Jillian Michaels. Since the rescue they have been doing well and been alive and thriving. During our emergency trek adventure into the burn zone!

Check Out Our Video!

Animal Rescue: This video is about Koi Rescue in the Woolsey fire by Jon & Ben Rasmussen of the Pond Company. Heading into the burn zone of the Woolsey Fire to save koi fish from a pond on 11/12/18.

Nitrogen Cycle


The Nitrogen Cycle occurs naturally and invisibly on a microscopic level within a pond or water garden. It is a vital, natural process in all healthy, organic, aquatic ecosystems so it is good to know and understand this process and how it works.

First, the fish waste and uneaten food becomes Ammonia. Ammonia (NH3) can be an industrially produced chemical, and it also is created and exists naturally in the environment. Ammonia is essential for many biological processes and serves as a precursor for amino acid and nucleotide synthesis; the nitrogen cycle. In the environment, ammonia is part of the nitrogen cycle and is produced in the water from bacterial processes. Ammonia naturally occurs from decomposition of organic matter, including plants, animals and animal wastes. Basically, when the fish feed, their waste (along with uneaten food) becomes ammonia. The ammonia molecule is then turned into the nitrite molecule.

Nitrite is a waste produced by bacteria in the biological filter as it breaks down ammonia. Nitrite is extremely harmful to fish if left in quantities unconverted. Tested levels of 0.25 ppm or higher are dangerous to your fish and if levels are allowed to rise up to 0.5 ppm, it can result in severe fish loss..

Biological filtration provides the environment for this nitrogen cycle to take place naturally. In this cycle naturally occurring bacteria (nitrifying bacteria or aerobic bacteria) break down the ammonia into the nitrites, and then is converted further; produces the byproduct called Nitrates.

Nitrate is the byproduct of nitrifying bacteria in the biological filter breaking down ammonia and nitrite; Nitrate can be taken in by aquatic plants and algae as a nutrient for growth.  High levels can lead to excessive algae growth. Levels should be kept below 40 ppm and should be tested weekly.

Thus, when the fish eat, their waste/the ammonia is converted by aerobic bacteria (the good bacteria) into the nitrites, and is further converted into nitrates. Nitrates then in this cycle become “food” for the plants to grow on (fertilizer) and then in turn, the fish eat the plant material as a food source, produce ammonia …..thus creating an on-going natural process called    completing the Nitrogen Cycle.

The Pond Company Promo Video

The Pond Company has been working hard to keep Echo Park looking Clean and Beautiful through our dedicated oversight and optimization over this past year of 2017.

Check out our newest video showcasing some of the work we have been doing at Echo Park:


Naturally Flowing Pasadena Stream

Recent work on a naturally flowing stream that runs through the hills above the Arroyo in Pasadena. We did a re-positioning of the rocks and boulders within to create an appealing landscape for the water to flow over and through. For the rain, we adjusted boulders and placed stones in an aesthetically pleasing way. IMG_20170117_142409 IMG_20170202_125931

The Amphibious Bullfrogs at Echo Park Lake

Bull FrogIf you listen close enough the next time you’re enjoying a nice day at Echo Park Lake, you’ll be able to hear some croaking sounds coming from the lake or see a rustle in the water lilies, and now you’ll know that its the Bullfrogs making their presence known from within the wetlands!

We have been noticing more and more that the Bullfrogs have been doing well and living healthy in the environment of Echo Park Lake. The Pond Company has been working hard and diligently to ensure that the waters are clean of trash and other debris so that the wildlife can live a healthy lifestyle out in Echo Park. We hope that our efforts can bring more wildlife to Echo Park, and also more humans to come by and enjoy a day at the park as well!