How not to install a bottom drain

I ran across this image and just had to rant about it. This is so wrong this pond professional should be banned from building anything.
You will notice the image shows a bottom drain running to a skimmer via 2″ pipe.

1) Bottom drain should have 3-4″ pipe minimum.

2) You can not run a BD to a skimmer because the face plate has more area for water to enter the skimmer than does the Bottom drain. You will not get effective draw through the bottom drain.

3) If some tries to tell you this is correct, fire them immediately and save your self some trouble.

To do it right, Add a separate box/chamber for the BD. One drain, one filter system, one pump. Skimmer should have it’s own pump and possibly filters.

IF YOU ONLY HAVE ONE PUMP – run the bd to a line outside the skimmer and use a wye into the pump circuit but have control valves on the skimmer and bd lines so you can adjust flow (which is still not ideal since you can not really know the flow through each line.)

Posted in Pond Building, Resources, Troubleshooting | Tagged , | Comments Off on How not to install a bottom drain

Koi pond at National Zoo

The National Zoo in Washington DC has a Koi pond. No show winners but it is always nice to see them in public spaces.
I do not have any pictures of it, but found this video on you tube. Koi at National Zoo Video

The koi at the National Arbetorium are a little bit better looking. Koi at National Arbetorium video

Posted in Wandering | Tagged | Comments Off on Koi pond at National Zoo

Book – Koi for Home and Garden

Koi for home and garden, Glen Takeshita, 1969, revised 1982.

This book provides an interesting look at the past beliefs about koi. The opening remarks about history is likely to confuse todays koi keeper since he talks of hundreds of years of koi breeding. However what he is referring to is the breeding of common Carp for food, not the colorful Nishikigoi we know today.

The ideas of pond building have certainly changed. At the time of this writing it was believed ponds as shallow as 2.5 feet were adequate since there was little oxygen in deeper ponds. It does touch on the need for filtration, water changes, and medications for diseases and infections. Parasites are not covered. Food was mostly hand made or was at least standard fish food supplemented with additional live food and vegetables.

The 1982 edition of the book is filled with colorful images of koi any of us today would be glad to have. There is even an image of the First All Japan Show winner. This book is more of a collectors item than a modern reference on keeping koi. It can be found fairly cheaply on Amazon.
LINK: Koi for Home and Garden ISBN0-87666-54-x

Posted in Resources | Tagged , | Comments Off on Book – Koi for Home and Garden

Gravity flow vs Pump Fed

New pond builders rarely learn the significant differences in water gardens vs “ideal” koi ponds. We tend to borrow ideas from aquarium technology, water gardens, water treatment, industrial processes, and even the ideas tried and tested for a long period of time. But one of the most common mistakes we make due to space limitations or even just laziness is the circuit from bottom to returns. What happens outside the pond is just as important as the design of the pond basin.

Small ponds will usually have a housed submersible pump that feeds a series of filters. Another common design is to use a retro fit bottom drain connected to a powerful external pump which feeds a bead filter and/or DIY filter (aka Skippy filter or box filter). This is my particular design and I am constantly having to clean the combo mechanical/bio filter as well as remove the debris from the pump basket. I can tell you it is not the ideal situation for maintenance.

The ideal koi pond, even if only 1500 gallons, needs a properly situated bottom drain (Not a retro fit drain) flowing by gravity to a mechanical filter chamber or settlement chamber/vortex. Koi produce a lot of waste. If this waste can be moved with minimal agitation it is easier to remove from the water column. If we use a retro drain connected to a suction pump, the waste is chopped up and is harder to remove and often ends up in our bio filters making them less efficient. I will rectify this within the next couple of years when I expand the pond.

Another advantage of gravity fed systems is that they generally require slower water flow. This means less energy used by the pump, and a smaller UV unit required. You can increase/reduce the flow by using variable speed pumps or by using a ball valve after the pump to create pressure head resistance. The bottom drain pipe to the first chamber should be as large as possible, usually 4″ pvc, so that the solids moving through the system can flow freely. Overtime this diameter may be reduced by bio layers and algae adhering to the sides. You can put your additional mechanical filters and bio filters after the first chamber before the pump, or put them after the pump. If using chambers in series before the pump you should learn about the properties of draw down due to resistance between each chamber.

This is also a good time to review raceway filter designs. A raceway is a long but shallow horizontal flow filter that sits outside the pond but at same water level. Generally dirty water is gravity fed from a bottom drain into one end of the raceway which acts as the mechanical settlement chamber. Water then flows horizontally through various materials to remove debris and then through bio materials that complete the nitrification cycle. The pump is placed after the bio stage in raceway filters. Water after the pump can go to falls, returns/jets, or even additional filters like trickle tower filters. The entire filter can be dumped on a regular basis to keep it clean. Raceways are often covered by decking so they even offer a platform for viewing the pond.

As with anything related to Pond building please research all your options and think about the details outside the pond. Your fish will thank you for keeping their environment as clean as possible.

Posted in Pond Building, Troubleshooting | Tagged , , , , , , , , | Comments Off on Gravity flow vs Pump Fed

Top posts for Pond Journals

Thanks for visiting my Pond Journal. The entries in this journal are my personal experiences and the advice I have gleaned from other experienced koi keepers. The pond conditions calendar entries are my ponds weekly water analysis. I hope you find something here that helps you prepare for your pond build or become a better fish keeper. You can use the search tool to poke around or use the menus at the top.

Top 5 Most Searched
How to replace Jebao-cw-55 bulb
Reduce Pump flow rate
Fix skimmer face plate leaks
Remove black foam from hands
Pond in wooden box

My Pond Calendar
Most popular posts/tags
Pond plumbing layout
Waterco Multicyclone
Water changes vs Chemical additives
Nitrification in a closed pond system.
Books for pond and koi enthusiast
Monthly Pond Conditions & Costs
Posted in Pond maintenance, Pond News, Resources | Comments Off on Top posts for Pond Journals

Potassium Permanganate in a koi pond


Last week I embarked on a different treatment for my pond. After reading several articles about parasites, fungus, bacteria, and all other sorts of nasties that live in the pond I decided it would be a good time to do a pre-emptive strike, just in case. I have seen the devastating effects of bacterial infections and know we get just about every type of parasite known to cause harm to koi here in the southern US. I need to learn to scrape and scope but until then PP is supposed to be affective against them all.

I had read about Potassium Permanganate for several years. I have also read all the horror stories about overdosing the fish. But upon further research I found several articles that tout its wide spread benefits if used conservatively. had a most reassuring article which helped me determine the dosage and proper treatment necessary. Also confirmed dosage at

PP works as an oxidizer and basically kills pathogens and even algae by boiling them with oxygen. It can be stopped by using 1 pint of Hydrogen Peroxide per 1000 gallons. The recommended dosage is 1 teaspoon per 600 gallons of pond water. I used less just to make sure. I used 2 teaspoons in my 1600 gallons or about 1 tsp per 800 gallons. I plan to do a multi-day treatment where it kills off the pathogens without harming the fish. Some folks will over-dose and do only a single treatment so research very well before you try this. The powder is added to a bucket of water and is added slowly to the pond. It starts off as dark purple then turns the water pinkish, then slowly turns a dark brown tea color then to a light tea color. You should use an airpump/airstones in the pond during this process.

In summary here is what I did:
1) Removed filters from my combo bio/mechanical filters so the PP would not kill my good bacteria but the treatment could circulate through the box.
2) Clean out pump basket of debris.
3) Empty multicyclone so its debris did not affect the treatment
4) I should have scrubbed down the walls of the pond to expose any bacteria living in the algae, but I didn’t
5) Put on rubber gloves and eye protection.
6) mix the PP in a liter/ .5 gallons of water then add to pond around the sides, especially near folds.
7) watch the water turn Purple, then pink, then brown over 2 hours (your time may vary)
8) 4 hours later, changed about 10% of the water, returned the filter mats to the filter overnight. The brown color dissipates overnight.
9) repeat steps 5-8 on the next day. Stayed pink less than 1 hour so there is much debris still in the pond. I added another 1/2 teaspoon.
10) repeat steps 5-7 on third day. Stayed pinkish for at least 4 hours so I am confident it is working.
11) Late on day 3 I added 1.5 pints of Hydrogen peroxide to change the brown tea colored water back to clear-ish.
12) performed a 30% water change.

I am not seeing the sparkly water everyone talks about but it is clearer with less floating algae debris. The algae inside the multicyclone prefilter even is gone. But I do expect to have Nitrite and possibly even ammonia show up in the next couple of days since I likely killed all the good bacteria that lines the piping, unless the bacteria in the filter matting is still strong enough.

UPDATES – 2 days later Nitrite and Nitrate have spiked but no higher than before.
One week later I am seeing the sparkle again, I have been changing out about 100 gallons per day. Nitrite is reducing again.

From a skills required standpoint this is easy to do. Be sure to wear gloves, eye protection, and old clothes.
From an “Am I confident I’m doing the best thing for my fish” rating scale I give it a mid point mark. If you are not overdosing you can be assured you are killing some parasites and bad bacteria. But there is always that lingering doubt when adding chemicals to a pond.
Cost – $30 for 1 pound from my local fish store – But you can find it cheaper online. I wanted it from a trusted source.

Posted in Fish Health and Medications, Pond maintenance, Resources | Tagged , , , , | Comments Off on Potassium Permanganate in a koi pond

Books – Live Jewels

Added another book to my now growing collection. Live Jewels – General Survey of Fancy Carp by Masayuki Amano. Published 1968.

It is written mostly in Japanese with some english translation. It is a great overview of koi history, development of varieties, pond building, and koi keeping as presented from the Japanese point of view in the 1960s. It should be read as a historical reference work for a greater appreciation of the development of the koi industry.

The book is covered with a blue board and mine has a plastic outer cover. The book has a cardboard container and the dust jacket fits on the outside of the container. I highly recommend this book as a gift to any koi fanatic if you can find it in good condition. has several copies available as of this writing.

Posted in Resources, Wandering | Tagged , | Comments Off on Books – Live Jewels

Books – Koi2Kichi

I just received a copy of Koi2Kichi and Koi Crazy by Peter Waddington. Peter is a leading authority on Koi in England. His initial book published in 1995 was, and still is the bible for most serious koi keepers. It can be found selling on ebay for anywhere from $300 – $600.

Koi2Kichi was a revised 2 book edition published in 2002 and covers everything from Koi history to Koi keeping. This is a well illustrated manual with detailed text about the hobby of raising koi. It deals with all aspects of the pond habitat and the medical treatment of koi. In addition there is an overview of the area of Japan where the finest koi are produced. Even includes a lovely map and details about the breeders.

Koi Crazy is a more condensed, less illustrated version of the first two books and was published in 2009. It revises some of Peter’s views on various types of filtration and illustrates the concept now known as ERIC filters (see Koi Crazy is a quick read for novices to koi keeping but beginners should read it at least twice through to pick up on the important parts. Filtration is discussed in detail with the shortcomings of all types of filters. There is nothing in this book to confuse the pond building aspects with water gardening or goldfish ponds. It focuses on koi ponds and koi keeping. I highly recommend this book before you do much other research.

In the UK these books can be purchased directly from Peter Waddington at his main site Here in the USA they are in limited supply at Great Wave Engineering. They can also be found on Amazon or ebay from time to time.

Posted in Resources, Wandering | Comments Off on Books – Koi2Kichi

Spring 2012 pictures of my pond

Here are a few snapshots of the pond.

The Whole Pond – You can see how shady it is under the bradford pear tree.

a close up of the falls

a side shot showing the water lilies blooming and the hyacinth beginning to grow in the veggie filter and one of the Mugo Pines.

Posted in Gardening, Pond News | Comments Off on Spring 2012 pictures of my pond

Filter considerations for your pond

Whether you own a garden puddle or extra large swimming pool for koi there are some things to consider when it comes to filtration. This article will not discuss which filter is best/worst but will hopefully help you narrow down your selection from the wide range of choices available, including creating one yourself.

1. What is being filtered?
Is this an all-in-one filter designed for Mechanical separation, biological nitrification, and chemical filtration? OR is this merely a single filtration unit in a system or group? You must determine the scope and size requirements of any filter you consider adding to your pond and assess its strengths and weaknesses within your system.

2. Is the filter designed for your pond or something else? Example: I once considered purchasing centrifugal separator filters that were designed for water purification. But upon further research I found they would clog with algae. Sometimes we pond owners also turn to pool industry products like bead filters. You must carefully research such items since their design assumes a low algae, high chlorine environment and so heavy dirt removal and nitrification are not really what they were designed for. We pond owners are often the targets of exaggerated claims by manufacturers too about the capacity of their products. Will that 12″x 10″ barrel with a 9 watt UV bulb really clean your 2000 gallon pond?

3. What is your budget? And more importantly what is the value of the pond and fish you are filtering? It is often said we are really water keepers rather than fish keepers so we could potentially spend more on the filters than the fish we keep. Some inexpensive to build DIY filters may perform as well as professionally produced products but may not be as attractive in the landscape.

4. For mechanical filtration – How small a particle are you trying to remove with the filter under consideration? Determine which types of filters are best suited for that particle size. If there is much debris in the pond from overhanging trees you will have more debris to remove than if the pond is indoors.

5. How often will you maintain the filter realistically? Maintenance can be easy or difficult to get the filter to like new condition. Also does the maintenance need to occur so regularly that you can not go on vacation?

6. Does the design of the filter allow for a thorough cleaning, or does backwashing leave a build up of potentially dangerous sludge. One fault that most equipment dealers will not point out is the amount of debris that remains in your filter during a normal cleaning. Bead filters may run clear during backwash but still contain a full inch of muck inside harboring bad bacteria. Other systems may seem clear after backwashing too, but until you remove the media you can not see the hidden dirt. Gravel bog filters are probably the best at trapping solids but are also the hardest to clean.

7. Can you see into the filter to determine when it needs to be cleaned? Many pond owners will allow their filters to run until they slow the water down due to sludge build up. It is important to regularly remove the K1, brushes, matting, or other components to insure the cleanliness of the filter.

8. How much water can flow through the filter when clean vs filthy? If your filter is a mat or sponge type it will slow water down as it fills with debris. It will also be less effective at both mechanical and biological filtration. Certain plastic media are designed not to slow water.

9. Does the filter have any moving parts and if so are they durable? Drum filters and Sieves with floating valves come to mind as filters with moving parts that can wear out, become dislodged, or fail for other reasons.

10. Is the size of the bio filter and it’s media adequate for your pond and its flow? How large it should be is a major issue for pond owners since there is no magic formula for all types of filters. If you regularly have ammonia and nitrite spikes your filter is not large enough for bio filtration. If your water is cloudy from fine particles, you do not have adequate mechanical filtration. You can not over filter a pond but usually must consider the aesthetics and placement of the filters for the garden area. This can lead to trade offs due to size and potentially inadequate filtration.

11. What is the filter made of and can it withstand the elements over time? Many are durable plastics or fiberglass and can last for years. Less expensive items may become brittle with time. Many of the DIY barrel filters and planter filters will need to be replaced every few years.

12. What Pipe sizes do the inlets/outlets support? Pipes and hoses to and from the pond are relatively inexpensive until you get to the 3-4 inch size. For Koi ponds a generally good filter design will use gravity fed from bottom drains to the filters then pump clean water back to the pond or other system components. A filter that only supports 1″ pipe isn’t likely adequate for a 4000 gallon pond and high pump flow.

13. Will the filter be pump fed or gravity fed? The hardest thing for me to grasp was the importance of a gravity fed system. The use of a bottom drain running to an external chamber will allow most of the debris that sinks to be carried away from the pond and dumped to waste. This debris is not chopped up by the pump and is thus easier to flush away. You can have just your mechanical filters gravity fed and then pump feed bio chambers if desired. For small water gardens where the pump is submerged in the pond you will have to clean your pump box regularly to keep the water flowing. well. Gravity fed systems have far more advantages than pump fed filters but require more planning during the initial build of the pond. Gravity fed units are usually at the same height as the water level in the pond.

14. Flow and Tracking – Filters are either upflow, downflow, or horizontal flow designs. Water will take the path of least resistance and will channel through the filter unless acted upon by another obstacle such as baffles, air bubbles, matting, or other media. The goal of any mechanical filter is to provide a barrier to dirt while allowing the flow of water. Bio filters should come in contact with all water passing through the filter to operate at maximum efficiency. Do note however that most bio filters have stagnant water areas which can lead to possible poor water conditions. Horizontal flow filters have the most efficiency for media contact and water can be easily disrupted with air bubbles or media in its path, which allows for maximum nitrification.

15. The magic box – There is no perfect filter for your pond regardless of what that nice salesman at the garden center tells you. The trick is to determine what size filtration you may need for your pond, check the water parameters regularly, then make adjustments to flow rates, aeration, UV power, and other system components that help your filter do its job. You may even need to change out that lovely overhanging tree to an evergreen to reduce the debris that falls into the pond. If you can talk to other pond owners and learn from their mistakes it will help you decide which filter is best for your pond and its inhabitants.

Do keep in mind that KOI ponds differ greatly in their filtration requirements than do goldfish ponds and water gardens. Buy the appropriate equipment for your pond and you will only have to pay for it once.

Posted in Pond Building | Tagged , , | Comments Off on Filter considerations for your pond