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Gravity Return Filter Units

Option 1. – With Built in 8 Watt UV, Which combines three forms of filtration

Firstly – Mechanical.

The water passes through three layers of foam. The first is fibre gauze that traps the larger particles. The other two are open cell reticulated foam, one 25mm thick and the other 50mm thick. These will remove most suspended solids from the water.

Secondly – Biological.
The water now passes over a number of Ultra Zap bio balls, which provide an excellent surface area for bacteria colonies to grow on. Millions of naturally occurring bacteria which live on the surface break down the toxic waste produced by the fish and uneaten food, they convert nitrites and ammonia into nitrates. Nitrates are relatively harmless to the Koi and are easily removed by water plants or by doing regular partial water changes, 10 % a week.

Thirdly – Ultra Violet Clarifier.

This unit will help maintain an algae free pond throughout the year (Free floating single celled algae). The unit works by exposing the algae cells to a dose of U.V radiation. The U.V. radiation penetrates the cell membrane and thereby either destroys or debilitates it.

Option 2 : Without UV light

This unit comprises of just the first two stages of filtration, as there is no U.V. Clarifier the pond might experience algae problems.

Installation:

The units must be installed above the water level or above the point where you require the water to flow over. The return pipe from the filter must be 50mm Ø and run at a slight gradient back to the pond. The inlet into the filter can be reduced to the required diameter using an Ultra Zap hosetail connection. It is important to pump only the required flow rate into the filter. If your pump delivers more that the required flow, you must install a valve and tee piece inline and divert some of the water. The water level should not rise above the top gauze when you first commence the system. The unit with the built in U.V. must not be buried or be in a place where the electrics can become water logged, also protect the electrical cable to avoid damage. The unit without U.V. can be buried.

Maintenance.

The unit requires little maintenance. Once a week remove the lid and check the water level inside the unit. Only once the water has started to flow out the overflow pipe must you clean the foams. Always only clean a maximum of two of the foams. Rinse the foams under tap water; be careful not to damage the foams. In time the foams will become damaged or too clogged to clean and then they will need to be replaced. Once a year remove all the bio balls and rinse them in pond water. DO NOT let them dry or the bacteria colonies will die. Clean out the inside of the filter. It is also important to keep the system operating 24 hours a day. If your pump fails or you have an electricity failure for a long period ± 6 hours you must wash the entire contents of the filter and start the system from new. It is recommended to do a regular partial water changes during a period of 1 month after the failure and to also monitor the nitrite and ammonia levels. A filter accelerant can be added to help speed up the filter start up cycle.

The U.V. tube inside the unit with built in U.V. must be replaced every 12 months.

Replacing the tube:

· Disconnect the unit from the water and power supply.
· Remove the clear end caps and gently pull the electrical connectors off the ends of the tube.
· Unscrew the blue locking nuts and remove the O-rings.
· Remove the tube.
· Make sure there is no water inside the unit before installing the new tube.
· Replace the O-rings with new ones.
· To install the new tube, just reverse the above procedure.
· When installing the new tube do not over tighten the blue nuts.

Check for leaks before turning the U.V. power on.

. Info Courtesy of Ultra Zap