The addition of pond plants are essential when creating a balanced pond.
The various types of pond plants include:marginal (hardy and tropical), floating plants like water hyacinth and water lettuce which are annuals, water lilies and lotus (hardy and tropical), and oxygenating plants like cabomba, hornwort and narrow leaf anacharis.
Typically marginal go just under the waters surface.Water lilies sit at the bottom of the pond at about 24" deep. Water lotus go 4-6" under the water. Having plants in a pond reduces algae because the plants consume nutrients which give rise to algae. In addition, plants provide hiding places for the fish, beauty, color and dimension for the pond, areas for the fish eggs to be affixed and finally places for baby fish to hide.
All annuals should be removed and discarded in the fall. All tropical should be removed and winterized in -doors or in a greenhouse. Hardy marginal like sweetflag, cattail, iris, and hibiscus can freeze. Other hardy marginals should be placed about 18" under water. Hardy lotus should be placed at 18-24" underwater. When winterizing the plants all dead or damaged foliage should be removed and discarded.
Pond Fish Compatibility
Generally speaking goldfish and koi are vegetarians and therefore compatible with each other.
When mixing various sizes of fish it is important to make sure that the food that is being fed is the appropriate size. In addition, as the fish grow it is important to increase the size of the food so that the fish will benefit nutritionally.
The following are different types that will co-exist in a pond:domestic and imported koi,comets,calico shubunkins. This season we have seen regular comets, red and white comets, apricot and lemon comets. I have also had some customers include fancy goldfish and channel cats with their pond fish successfully.
Generally if the pond is more than 24" deep the fish should winter with the aid of a pond heater. The pond heater is not meant to heat the pond but rather to have an opening so that there is a gas and air exchange. Unfortunately with this years harsh winter many ponds lost fish. I believe that aerating the pond with a pond heater amounts to cheap insurance for your fish and therefore should be used by all pond customers.
How to manage your pond
Now that our Koi and goldfish ponds have had their annual spring cleaning we are ready for an enjoyable water gardening season.
I have always stressed that customers attempt to create an ecco system of balance.In this ecco system of balance we are striving to achieve good water quality and clarity by having the nutrients from fish waste,energy from the sun,live plants,filters,and additives all balance out.In order to achieve this the pond should have at least 40-50%live plants,not be overcrowded with fish.The fish cannot be overfed and the filters must be kept clean. Tadpoles and snails also help in creating this ecco system as they are algae eaters. Barley,barley extract and algaecides can be used to also control algae growth and water clarity.
In cases where water clarity ,despite best efforts,cannot be achieved installing an ultraviolet sterilizer(UV) will resolve algae issues.
The UV needs to be the proper size for the pond.ie.the volume of the pond must pass the UV bulb once per hour and the sterilizer has to be rated by the manufacturer to handle that volume. Please note that if the filter begins clogging up the pump volume will decrease causing less water to flow past the UV therefore the filter needs to be kept clean for the UV to be effective.
Spring Cleaning Koi and Goldfish Ponds
Just like many people perform spring cleanings on their homes and apartments, owners of Koi and Goldfish ponds should be thinking about performing spring cleaning on them.
Weather and temperature permitting, I usually begin doing spring cleanings for customers mid April or there abouts.
While I am sure there are many methods to cleaning a Koi or Goldfish pond, my method has been refined by nearly thirty years of field testing and experiences. I would also like to add that throughout these hundreds of cleanings we have had only one fish fatality when a small Goldfish jumped out of a holding container and remained out of water unnoticed.
As is the case when dealing with livestock, the sequence of steps is critical and time is of the essence.
1. Pump water out of pond into appropriately sized aerated containers.
2. Pump water down to about 6" high.This will facilitate fish removal.
3. Remove,if possible,live plants and cover them with wet newspaper.
4. Catch fish,cover aerated containers to prevent them from jumping out.
5. Pump out remaining water.
6. Powerwash sides and pond bottom.
7. Pump out and remove sludge.
8. Clean filters.
9. Refill with tap water.
10. Add appropriate amount of water conditioner and pond salt.
11. While refilling ,return fish and plants into pond.
Feed sparingly over the next few weeks and monitor water chemistry.