Why Water Quality is So Important to Pond Fish Health

Most people with garden ponds will keep fish. Some will be happy with a few goldfish swimming happily between the aquatic plants while others will want to grow koi to optimum size and there will no plants in the pond at all. Whatever the type of fish pond ensuring the health of the fish is good at all times is an important consideration for all pondkeepers.

The fundamental concern when addressing the wellbeing of fish in a pond is to make sure the water quality at all times is excellent. By doing this we will maintain an environment where the fish grow, breed and live a long life much to the pleasure of us, the owner and pondkeeper.

If we make water quality the utmost priority in our ponds koi and goldfish will look after themselves to a large extent. Conversely poor water quality will lead to a myriad of fish health problems and even lead to fish dying unnecessarily..

A Note on Buying Fish

Only buy fish in small quantities at any point in time. Rather take time to build up a collection than risk a mass failure of newly introduced fish as well as established residents. Adding new fish to a pond is a prime source of disease.

Water Quality

For most ponds having it well-planted, will aid the stability and water quality aspects of the pond since plants take up nitrates and add oxygen to pond water. Every pond with the exception of top end koi ponds should be planted with a range of marginal, oxygenating and surface plants. These plants help in establishing the myriad of life forms that hold a pond and its water quality in balance by acting as natural water purifiers. In addition they provide for shade and breeding areas where eggs can be deposited and newly hatched fry can hide.

A well planted pond might be all that is needed to keep a pond with a low stocking level in equilibrium. However for most ponds the plants alone are insufficient to maintain water quality of a high standard. To achieve high levels of water quality human intervention using biofilters is necessary. Biofilters are necessary because fish grow, new fish are introduced, fish breed and other forms of aquatic life have an influence on water quality.

Take a look inside any fish retailer's store and the water holding fish for sale will be greatly overstocked yet the water quality will be excellent. There are two reasons for this exceptional water quality: Bilfitration is of a high order and aeration of the system is continuous. We don't see the filters and other equipment for maintaining good water quality because they are out of site in the backroom.

Why does a pond need a filter?

Most ponds need a biological filter to handle and purify waste products emanating from a fish's natural metabolic process. A fish eats and therefore secretes ammonia into the water. If allowed to build up the ammonia will reach toxic levels. Aerobic bacteria inside a pond filter do this job of purification by continuously removing impurities (ammonia and nitrites which are oxidation products of ammonia) as water is recycled through the filter. A pond filter must run 24 hours a day in order that the bacteria performing the job of maintaining water quality will not die. This means you should never switch off a pump feeding the filter for long periods of time because bacteria in the filter will be deprived of oxygen and will die making the filter ineffective.

A filter properly sized will maintain high levels of water quality and it need not cost an arm and a leg.

The Bigger a Pond is the More Stable is the Water Quality.

Every pondkeeper must be aware of the need to maintain high levels of water quality in the unnatural pond environment where overstocking is almost always the case. Overfeeding adds to the problem of overcrowding in a small pond. Control of water quality is more easily achieved in larger ponds where stability can be maintained more easily. Larger ponds do not see significant spikes in ammonia levels for example after feeding fish because the ammonia is more diluted in the higher volume of pond water.

The Impact of Food and Feeding on Water Quality

Most people overfeed their fish and this can lead to water quality problems because the filter cannot handle the extra load placed upon it and ammonia levels reach levels that can stress the fish. Fish can survive for quite a long time without any artificial food being given.

In feeding fish it is always best to feed a high quality food balanced with high protein levels, and low ash levels. The food should be highly digestible and fed in small quantities.It is better to feed small quantities more often than large quantities in one feeding session.

Many fish foods these days contain colour-enhancing compounds that increase the vivid colours of goldfish and koi. Such high quality pond foods contain items like paprika, krill, marigold meal, spirulina and algae! High quality fish foods also contain all necessary amino acids and a range of vitamins to promote fish health.

Your Fish are Reliable Indicators of High Water Quality

By observing the day to day activities of your fish you will be able to notice differences in behavior quite easily. Fish gasping at the surface for example is indicative of lack of oxygen in the water or an excess of ammonia.

If fish go off their food this is another sign that water quality is not what it should be. By observing your fish and highlighting unusual behaviour early can often be the difference between life and death for your fish.

If you suspect a water quality problem at any time immediately stop feeding, and initially test for ammonia and nitrite which indicate whether the biofilter is working or not.

Poor water quality is normally associated with a biofilter not working properly or an excess of food being fed to fish in the pond. Adding lots of new fish will certainly impact upon filter performance and thus water quality. Remember as fish grow they eat more and it is quite possible that the existing biofilter just reaches its performance limit at which point it may need to be changed or increased levels of biomedia need to be added to the filter to bring the water quality back to where it should be.

It is always a good idea to pump out of the pond small quantities of water occasionally and replenish with fresh water. This helps in keeping nitrate levels down maintaining high water quality. Vacuuming the bottom of a pond will assist in removing organic debris that can rot in position. Water quality can be improved by adding bacterial products such as Viresco which removes nitrate and breaks down organic pollutants in ponds.