(Provided by Jamie Beyer, Water Garden Consultant)

All KEYS pertain to a balance of keeping organic load down by decomposing the organics and by simply limiting organic additions.  (Organic material) is anything that was alive).  However, chemical algaecides (a compound that kills algae) can upset the biological balance we are trying to achieve with these KEYS.  These chemicals are not necessary and are to be avoided.

FIRST KEY:  Do not overstock with fish. 
The following are just guidelines:

• 1" of fish/10 gallons without circulation or 1" of fish/5 gallons with circulation or 1 or 2 fish (3-5" size)/sq. yd.  of pond surface area without circulation.  There are a lot of variables besides circulation that affect these guidelines such as water temperature, kind of fish, and amount of plant materials, to name a few.
• One of the wonders of water gardening is that fish breed easily and consequently have babies.  Every year you will need t give away fish to friends or the pet store to keep the fish population within reason.

SECOND KEY:  Add plants 

• Simple enough.  Plants utilize decomposing organics.  Floating water plants, such as Water Hyacinth and Water Lettuce, are excellent "plant filters."  Submerged plants (Sometimes called oxygenators) are also very helpful.  Plants can also shade the water preventing algae from getting enough light.  If you have a 60% coverage of the pond's surface by lilies and floating plants, you are less likely to have a problem with green water.
• Phytofilters (Veggie filters) can be included in a water garden's design.  Pond water can be pumped through a separate pool containing large populations of plants.  Another alternative is to add "The Grid" (patent pending) or something similar.  This technique is a veggie filter using iris planted on a grid which allows the plant roots to tangle in the water.  The Grid can replace biological filters which eliminates a lot of expense and maintenance.

THIRD KEY:  Do not overfeed your fish or plants. 
This is an easy one but is the KEY that will get abused if not understood.

• Healthy fish will always beg for food no matter how much they have been fed.  Fish do not have to eat 3 times a day, every day, like humans.
• Feed only enough food that the fish eat it all in 5 minutes.
• Feed no more than once/day.  If you want to feed more often, then reduce the amount you feed each time.
• Keep plant fertilizer in the plant container.  Your plants definitely need fertilization on a regular basis but contain it in the plant's pot.  Use fertilizer for floating plants that is made for adding to water in water gardens.
• Keep runoff during heavy rain events from entering the pond.  Lawn fertilizer, animal droppings, and chemicals that are applied to the landscape can easily be carried in this way.  Overspreading and overspraying of fertilizer and chemicals can also be a problem.

FOURTH KEY:  Keep most of the debris, dirt and dead animals out of the pond. 
They contribute to cloudy water two ways:
1) Increase silt or other tiny particles which may stay suspended in the water.  You can reduce this by:

• Keeping fish from disturbing dirt in the plant pots by covering the top of the dirt with gravel.  Certain kinds of fish (especially large koi) can dig in plant pots which will create cloudy water simply by their action of digging in the dirt.  These pots need a covering of gravel to keep the soil in the pots.  Large gravel (2- to 3-inch) is needed on pots that big koi have access to.  Whereas, pea to ¾-inch gravel, is big enough for goldfish type of digging.
• Keeping small fish in your pond.  Larger fish will "root" on the bottom keeping silt and debris suspended.
• Adding a settling basin (or pool).  The design must be large enough (or water flow, slow enough) so the suspended silt has time to settle before flowing back into the main pond.  A separate veggie pond (suggested under the Second Key) can serve this function.
• Adding a bottom drain so that sediment can be pulled off easily.
• Using no-hole plant containers or line open weave baskets or containers with holes, with landscape fabric to contain the soil.

FIFTH KEY:  Create a good home for bacteria and invertebrates (protozoans, crustaceans, small worms, etc.). 
These critters are the basis of a healthy ecosystem.  They exist in the water and as a layer of growth (a PATINA) on pond walls, lily pots, rocks, plant roots, etc.  It takes over a year and sometimes two for the patina layer to fully mature.  We want to preserve and promote the patina and the critters.  We do this by:

• keeping the water well oxygenated with good circulation.  Locating the intake at the opposite end of the output of the water pump is a much.  Aerators, fountains and/or waterfalls can also help achieve this goal.
• not "scrubbing" out the pond or "power washing" (this is also a lot of work).  You would be scrubbing off the patina.  If you want to clean, then just spray it off - no more than that.  It is obvious to say, but our ponds are not swimming pools.  Do not try to achieve this kind of pool and expect a healthy, in-balance pond.
• not letting the patina layer become too dry when the pond is emptied or when the pots, rocks, etc. are taken out.  Keep the layer moist by spraying with water.  Once dried, the majority of the animals and good algae have died and you start back at square one in reestablishing this critical part of the ecosystem.
• not using any chemicals or soaps that may accidentally kill our good guys.  Ninety percent of the water additives sold to ponderers are a way to separate them from their money.  They may be a quick fix for a problem but when added could create other, bigger problems.
• making periodic water changes (that is; if it doesn't rain much).  This reduces a toxic buildup of salts due to evaporation.  Do not change more than 20% of the volume at any one time.  Any more than that then you will need to add chlorine remover (a water additive).  Of course, this isn't necessary if you have well water.  Also, "new" water is relatively sterile.  That's why most ponderers experience at least a short period of cloudy water (which is a type of algae bloom) in the spring.  Most of the bugs are just coming out of their restive stage and are in very low numbers at that time of the year.  When pond temps rise above 50 degrees F., they quickly reproduce in huge numbers to create healthy, "aged" pond water.  Aged pond water is normally healthy water - great for fish and other critters.  There are lots of those small critters (bacteria, protozoans, etc.) swimming around that are extremely healthy for the pond.  They are the basis for a healthy ecosystem.  You can add a commercially prepared bacteria which may speed up the establishment of bacteria colonies.  This is usually not necessary since the right kinds of bacteria are everywhere, and they reproduce exponentially given the above conditions.

SIXTH AND FINAL KEY:  As a last resort, if you still have cloudy water and have closely followed the KEYS, use a Biological Filter and/or Ultraviolet (UV) Clarifier.

• A biofilter and the media inside it, is simply an ideal place to grow huge numbers of beneficial bacteria and other good critters.  A patina layer grows on the media.  This is the same patina growth referred to earlier.  Your pond ecosystem is a biological filter in itself.  Adding a bio filter increases the entire population of critters that eat up the dissolved organics.
• I do not recommend adding a biological filter unless you are unable to follow the above five KEYS closely.  A properly maintained biological filter will allow some KEY mistakes to be made.  These filters add to the maintenance and expense of a water garden, and I believe, it is easier to follow the KEYS.  There are exceptions to where a biological filter is definitely a necessity.  Koi ponds without a separate veggie/settling pond is one.
• Most of the biological filters on the market are overrated for what they advertise.  However, there are some good products.  If you're the handy type, you can build a filter easily.  Refer to my handout on biological filters for guidelines on choosing or building one.
• If you still have cloudy/green water after adding a good biological filter and the other KEYS are followed, you may consider a UV Clarifier.  This will kill free-floating algae in a relatively harmless manner to the rest of the ecology of the pond.  I have not experienced any pond yet that needs the UV Clarifier when the KEYS were followed.