Stapeley Water Gardens

Water quality & Maintenance
When we talk about good water quality we are actually looking at how suitable the chemistry of the water is for the fish and plants, rather than its clarity.
There are any number of chemicals that could find their way into your pond by fair means or foul, and reach levels that could stress or directly kill fish or plants, but, if you do experience a problem with the pond's water quality, it will, in all likelihood, be in relation to one or more of the following:

pH
This is a measurement of the water's acidity or alkalinity and runs on a scale from I (very acid i.e. battery acid) to 14 (very alkaline, i.e. caustic soda) with a pH of 7 being neutral. Pond fish and plants generally prefer a pH between 6.5 and 8. If levels rise or fall outside of this range, or the fish are subjected to a sudden pH change, they can become severely stressed.

Most tap waters have a pH of between 7 and 8, but before you add fish or plants to a pond, it would be worth checking your pond water's pH. In a new pond, untreated concrete or mortar is the most common cause of a pH reading above 8, whilst the use of a very peaty soil could cause a lowering of the pH, especially in soft water. Later on the activity of plants and algae can potentially cause the pH to fluctuate, possibly rising during the day to a dangerously high level. If the pH drops longer term, a number of factors may have come into play. The water may be soft (the lack of dissolved salts reducing the water's buffering capacity, making pH swings more likely), there may be a lot of biological activity, or mulm build up in the filter or pond (carbon dioxide dissolved in the water from the respiration of fish, plants and bacteria can cause the pH to drop). There may also be lack of aeration (where oxygen is exchanged for carbon dioxide, in the water).

Partial water changes, increased aeration and the carefully measured addition of baking soda to buffer the water, (only once the pH has been brought above 7.5) will improve things in the short term. The addition of an appropriate amount of limestone chippings can prevent the problem in the future. Although commercial pH adjusters are available, in most cases it is preferable to identify the cause of the problem, address this and then gradually return the pH to normal with daily 40% conditioned water changes. pH test kits are cheap and easy to use, and a test once or twice a month, especially at different times in the day can be useful.

Ammonia, Nitrite and Nitrate
Ammonia is excreted directly by the fish, but it will also occur due to the breakdown of proteins i.e. any organic waste such as uneaten fish food or a dead fish. Ammonia can be very toxic if it builds up to a sufficiently high level. Fortunately in a balanced pond, plants and bacteria in the pond and/or filter, will remove or break down ammonia preventing its build-up. Bacteria actually reduce ammonia (NH3) into nitrite (NO2), which is also toxic. However, other bacteria reduce nitrite into nitrate (NO3), which is much less harmful. Nitrate levels need to increase to very high concentrations before they can affect fish, indeed problems may occur if the nitrates cause a pH reduction, or if new fish are added to very high levels. The main problem with nitrate input is that, along with phosphates (again input via fish waste and waste food), it encourages the growth of algae - especially blanket weed.

Plants and algae remove nitrates; therefore we are only concerned by nitrates in koi pool type systems, where partial water changes will help maintain low nitrate levels. Individual or combined test kits are available for ammonia, nitrite and nitrate, and testing is both cheap and easy. Kits come with a leaflet that explains the test results, and will offer possible reasons for unsuitable readings, with recommended remedies. Ammonia and nitrite testing is useful in most pools during the first few months that fish are added, as overstocking at this time is more likely to result in high ammonia and nitrite readings. Testing is essential in a pool where you rely on a biological filter to maintain good water quality for the fish. Nitrate testing is more relevant in poorly planted or heavily stocked fish pools.

Oxygen
It is obviously essential that dissolved oxygen is maintained at appropriate levels. Even in a still pond, oxygen from the atmosphere will dissolve into the water. However, levels can become critical due to any of the following:
1. overstocking with fish.
2. excess surface coverage, reducing the true surface area.
3. excessive plant growth and algae, which can reduce oxygen levels during darkness.
4. chemical treatments 'burning up' oxygen.
5. excessive bacterial activity.
6. increased water temperature - the water's ability to 'hold' oxygen decreases as the temperature increases, whilst at the same time the fish's demand for oxygen increases.
In clear water with appropriate fish stocks, oxygen shortage is very unlikely Water movement from fountains, waterfalls, and filters all help to increase aeration by circulating water and disturbing the water's surface. The most common reason for oxygen shortage tends to come from pumps failing or being turned off, especially at night, or due to the combined effects of still, warm weather and green water. An emergency measure would be to carry out a partial water change by spraying tap water vigorously over the pond surface, ideally late in the evening.

Signs of Oxygen Shortage:
1. fish gasping lazily at the water's surface, especially near moving water and in the early hours of the morning.

2. fish losses, which seem to occur mainly overnight and are initially limited to larger fish, especially orfe or rudd.

If you feel that oxygen shortage is, or could be a problem, liquid test kits are readily available and are cheap and easy to use. If levels are testing appropriately, in all likelihood, fish are gasping because they cannot utilise the oxygen that is present, possibly because of gill damage (which is most commonly caused by parasites or poor water quality).

Water Improvers
There is now a massive range of treatments on the market which are not direct disease treatments or algicides, but aim to improve water conditions and help reduce problems by tackling their root cause.

PH adjusters
for quick and easy adjustment of pH. However, they must be used with a test kit and may not always adjust the pH on a permanent basis, especially if the cause of the problem is still present. Most useful in adjusting the pH after the cause of the problem has been identified and tackled, in place of large water changes.

Bacteria/Enzyme-based products
all ponds contain beneficial bacteria which carry out many essential duties. Most of these bacteria and enzymes can be freeze-dried in a powder base, or held in a liquid, so that you can add them to your pond in booster levels. When added to water above 10°C, they can reduce dissolved waste product levels, improving the water conditions for the fish, and reducing algae growth in the long term. They can also reduce sludge/mulm build-up and help 'fire up' biological filter systems.

Filter start-up agents
similar to above but these only help to 'fire up' new or previously shut down filter systems. Filters will naturally establish without their use, but these products speed up the process, which can prove to be very useful if you have overstocked or have to re-establish the system in the spring or after a strong fish treatment.

Mineral powders
naturally occurring clays in a powder form that can have various benefits to the fish and pond, depending on their formulation. They will add important trace elements and minerals to the water, which can improve fish health, skin quality and colour; and some treatments can reduce dissolved toxic waste levels and help improve water clarity.