[John Russell]

Hello Don,

Thank you for the questions. Here are my answers.

Yes, Mr. Russell . . .
please address the following points which we, as evolved koi keepers, would consider absolute minimums that any pond would have to meet prior to being considered a 'true' koi pond by any serious koi keeper:

1. Volume
Russell Watergardens is a little different in calculating "how much water a koi needs". There on many "rules of thumb" that are correct, but only to a point. 10 gallons per inch, 100 gallons per 10" are all fine places to start - but these calculation do not consider the filter's capabilities. Our philosophy at Russell Watergardens goes a step further and takes into account the Total Specific Surface Area (SSA) of the biofilter and pond in relation to how much waste in can metabolize per 24 hours. According to many sources found around the internet (links below) - biofilters metabolize an average of .1 grams of fish waste per square foot of biofilm. It takes roughly 50 square feet of biofilm to metabolize 1 gram of ammonia per day. Koi produce approximately 1/3 of their weight in waste every day.

So, with a minum of 10 gallons of water per inch of koi - we also add the biofilters SSA and the pond's SSA to the mix to tell us exactly how much fish - by weight - that can be placed in the pond.

The Total SSA tells us exactly how much fish waste and ammonia the pond and filtration system can metabolize per 24 hours. The total fish waste tells us how much fish - by weight - produced it. The total amount of fish weight tells us what size fish, or fishes can be placed in the pond.

The reason we take this approach is because 10" of fish could be 10 1" fish, 5 2" fish, 2 5" fish, or 1 10" fish. Fish produce waste and ammonia in relation to the weight - not length. For example, a 1" koi weighs (on average) .28 grams, 10 of them have a combined weight of 2.8 grams. BUT, a single 10" koi weighs (on average) 275 grams! Koi produce approximately 1/3 of their body weight in waste per day - so the 10 1" fish with their combined weight of 2.8 grams only produce .93 grams of waste per day - but the 10" koi produces a whopping 91.67 grams of waste every day!

The 10 1" koi, in addition to the 100 gallons of water they require, needs a minium of 9.3 SSA filter/pond biofilm SSA to metabolize their .93 grams of waste per day. (.93 / .1 = 9.3 SSA)

The 1 10" koi, in addition to the 100 gallons of water it requires needs a minimum of 916.70 SSA filter/pond biofilm SSA to metabolize its 91.67 grams of waste per day. (91.67 / .1 = 916.70 SSA)

So you see, for the correct volume of water and koi - we also need to look at the total intended fish weight (including future growth) of the pond to calculated exactly. For example, a biofilter with 1,200 SSA could metablozie 120 grams of fish waste per day. (1200 x .1 = 120). That 120 grams of fish waste was created by 360 grams of fish weight. Look on any fish wieght chart to see what 360 grams of fish equals.

Koi need a minimum of 10 gallons of water per inch in length AND 3.33 square feet of Specific Surface Area (SSA) biofilm per gram of total fish weight. This tells you how much water, and how much SSA your biofilter requirements are.

Metabolization formulas and links to sources may be seen here:
http://www.russellwatergardens.com/metabolization.htm

Fish weights and pond stocking levels based on SSA may be seen here:
http://www.russellwatergardens.com/P...ishweights.htm


2. Depth

According to the many breaders I have met in Niigatta Japan, as well as Mr. Mamoru Kodama, as well as many of you tell me - the recommended water depth for optimum koi health is 3 times deep as the longest koi. For example: A 10" koi should have a minimum of 30" of depth, an 18" koi should have a minimum of 54", and so on. Keep in mind koi grow - so make the pond three times as deep as you think your largest koi will grow. This 3:1 ratio is for optimum conditions for koi - and the rule is not "set is stone". The water can be slightly deeper or shallower and the koi will be fine.

3. Pumps & Circulation (turnover and TPRs)
In ponds 10,000 gallons and less, I recommend turning the water over once per hour through the filtration system. This is to help reduce ammonia spiking - especially right after feeding. On ponds 10,000, but under 20,000 gallons - once every two hours is sufficient. Ponds 20,000-40,000 once every 3-4 hours is fine. Over that we get into once every 6-24 hours. The higher the water volume, the more dilluted ammonia gets in relation to "parts per million".

As for pumps. No submersible pump is rated for "swimming use". Meaning that they should be disconnected from the power source before a human enters the pond. In all cases, they should be connect to GFCI protected circuits. Submersible pumps typically are less expensive to purchase than centrifugal pumps, but more costly to run. The usually have higher head capabilities are most often prefered when build large - or high waterfalls. Submersible pumps hide inside skimmers and are much easier to plumb.

Centrifugal pumps are much more effiecient in terms of electrical usage. They have know electric motors in the water - so they are prefered in you intend on getting in your pond. They are typically more expensive to purchase than submersibles, but last longer and use less power so they pay for themselves fairly quickly. They aren't as easy to plumb, or hide, than submersible pumps. But, they can be placed virtually anywhere, wheras as submersible is almost always inside a pond skimmer. Centrifugal pumps can be connected to pond skimmers and bottom drains - submersible pumps have to have bottom drains connected to the pond skimmer.

4. Bottom Drains
Bottom drains are a "must have" item on all bare liner ponds - be they rubber, polyurea, gunite, etc. Bare liner only has an SSA of 1, and thus doesn't have much biofilm on it to help break down settle debris. Bottom drains facility easier removal of settled organics on the bottom of the pond and make cleaning the pond bottom much easier.

Bottom drains should not be used on gravel bottom ponds for clogging purposes. Also, the downward force of the water current would causes more debris to get sucked downward to the gravel instead of horizontal to the skimmer. The gravel doesn't let the debris to "skip" across to the bottom to get into the bottom drain - and thus cause more problems that its worth.


5. Skimmers
Skimmers are essential in all bodies of water in all situations to capture and facilitate removal of wind blown debris.

6. Supplemental Air
Supplemental air is reccomended on all ponds deeper than 24" for multiple reasons. The first is to increase disolved oxygen, the second is to circulate bottom water upward. As the air bubbles move upward, they pull water upward also - creating a bottom to top water current. The third reason is for keeping a hole in the ice open in freezing temperatures.

7. Settlement Chamber
Settlement chambers are great when space and customer's budget allows. They place less burden on biofilters by removing higher amounts of solid waste than mechanical filters can perform on their own. The key to settlement chambers is slow water movement.

8. Mechanical Filtration
All water features of any type should have mechanical filtration of some sort. Typically pond skimmers have mechanical filtration characteristics in addition to floating debris removal. Mechanical filtration, whether it is inside pond skimmers, or between settement chambers is accomplished with brushes, and/or various types of filter pads. The key to mechanical filtration is servicability.

9. Biological Filtration
In bodies of water containing any living creature from frogs to koi absolutely require biological filtration. There are many types, and brands of biofilters - they can also be "hand-made". The key to any biofilter is how much Specific Surface Area (SSA) does it have? How do you clean it? How does water enter and exit it?

10. Off-gassing (TT, Baki, &/or falls & streams)
I don't know what TT or Baki is - but Off-gassing through falls, streams, or fountains is essential to ecosystems for the purpose of releasing nitrogen into the atmosphere. Nitrogen is a byproduct of the nitrification cycle. It is also recommend that when filling, or re-filling a pond - the water source should be above water level for Off-gassing of chlorine gasses, and other gasses that may be present.

12. Water changes (%age & frequency)
Water changes in ponds without significant aquatic plants should be at least 20% per week. Nitrate is a byproduct of the nitrification cycle. In ponds with significant aquatic plants, the nitrates are consumed by the aquatic plants. In ponds with significant aquatic plants there is virtually no nitrates left in the water, so a minimum of 5% per week is ideal.

13. Rocks, gravel & plants
Rocks, gravel & plants are "good" and "bad". Rocks and gravel increase the total SSA of the pond - which increases the ammonia and fish waste metabolization - but if not kept clean ON A REGULAR BASIS become harmful to the ecosystem. Clean R&G add to the overall SSA biofilm. On average, a 2" deep gravel layer has an average SSA 8. Bare liner has an SSA of 1.

Dirty gravel adds to the bio-load of the pond and reduces the efficiency of the biofilter itself. Dirty gravel creates a build-up of mulm & detritus organic sludge on the pond bottom. This organic sludge adds to the organic load that can encourage algae growth in the pond (both green water algae and string algae). Organic sludge can also reduce dissolved oxygen levels in the water that can produce anaerobic zones that support pathogenic bacteria like Aeromonas and Pseudomonas. These bacteria strains have been linked to fish ulcers and death. Organic sludge also provides a breeding ground for parasites, flukes, and protozoa that can infect fish and cause severe health problems.

Clean gravel adds to the biofilm SSA for faster ammonia removal. Provides for "ammusent" for fish. Clean gravel keeps the sun's UV rays from deteriating rubber liners, provides "balast" to keep rubber liners in place, and is more decorative than bare liner.

Rocks in the pond can be hazardous to fish with non-related rock related health problems. A fish with any sort of skin or gill irritation will scratch, or "flash" against rocks. This may potentialy damage the fish'es scales or skin - rendering it less valuable.

Aquatic plants consume nitrates from the water that would otherwise feed algae - free floating and string. Aquatic plants provide shade to the fish, and add beauty to the pond. Aquatic plants can introduce parasites into the pond - so before placing aquatic plants in ponds, it is recommended that they recieve a "dip" in Calcium Permanganate or similar anti-parasite treatement. Aquatic plants can also be a source of entertainment for fish - as well as spawning material.


Please take it from me, John, if you won't (or can't) address all these points right up front then I'm afraid you're not going to enjoy posting on this board. Don
__________________
Don

Thanks for the great questions Don! Keep'em coming.
Sincerely,
John Russell