Over the years we have been asked 1000's of interesting questions by our customers. Although many are simple one-line answers, they can sometime be that snippet of information you just can’t find anywhere. Feel free to search our FAQ archive or just have a browse and see what you can find.
If you can find what you're looking for, you can ask us by using our Ask a Questions Page
Sorry we don't have any FAQ's matching that search phrase.
General Pond Questions and Answers
Generally to prevent pond water from turning green you require 60 - 70% surface cover. This can be achieved using Lilies, Water Hyacinths and Water Soldiers to name but a few of the selection available. By producing the shade in this way you not only cut out the amount of light reaching in to the water, but you also introduce plants which will compete with algae for the available nutrients.
The guarantees offered with liners nowadays cover the degradation (cracking/becoming brittle) of the liner by sunlight, they do not cover the more common dangers of puncture to the liner. The threat to liners comes from both above and below ground. Above ground the threat can be from Herons, Dogs, Cats and of course the stray spade. Below ground the threat is generally from stones and plant root systems. The more expensive materials such as Elevate PondGard (Firestone) EDPM Pond Liner, Greenseal EDPM Pond Liner or Butyl Rubber Pond Liners will generally be thicker and as such will be strong and less likely to puncture. You therefore need to weigh up the possible dangers to your liner before deciding what grade to purchase. If you are likely to experience any of the above problems then you should opt for Elevate PondGard (Firestone), Greenseal or Butyl. If not then PVC should suffice.
When introducing fish in to a garden pond it is important that you check the water quality first (Ammonia, Nitrite, Nitrate) with apond water test kits, to make sure the water is safe for introducing new fish, if it is not the problem should be resolved before the fish are introduced. When buying fish from an Aquatic Retailer, always make sure they introduce plenty of oxygen in to the bag, this is both for the fish to breath during their journey and because they will need floating in your pond. When reaching your pond you should float the fish in the pond with the bag still sealed for approximately 30 minutes. After which the bag should be opened and the sides rolled down (to create air pockets) and the bag should be topped up with a proportion of your pond water added to give a 75/25 mix. After 15 min's a further top should be done to give a 50/50 mix. Once this has been floated for 15 minutes then the fish can be released by submerging the bag just under the water and letting the fish swim out.
When making a solid water fall such as the one you describe, the first thing to consider is that you require a solid base, this is to avoid the possibility of settlement, which could wreck all your hard work. Yes the slabs should have a downward angle, 5 degrees should be adequate, this is not only to allow the water to flow down them efficiently, but also to help prevent water from trying to travel back under the slabs. Ideally the slabs should have a ridge on the underside running along the edge that the water will fall off. This will further help prevent the water trying to travel back under the slab. We would recommend that the slabs over lap one another and the pool by 75mm (3"). As you may have gathered from the advice above, their is a significant risk of leaks on a purely Slab and Concrete waterfalls. We would recommend that the construction be built on top of a pond liner, so that even if the waterfall does spring a leak the water is captured. With regard to the water flowing away from the pond, if you choose to use a liner then this should not be a dramatic problem. Other than this either the slabs need to be contoured to channel the water flow or the slabs will require an edge. In terms of flowrate and the sizing of apond pump, one of the hardest problems is visualising the flowrate you require. To help with this we use these guidelines.
To create a 12mm (½") depth of water 30cm (12") wide a flow of 4500 litres per hour (1000 gallons per hour) is required.
To create a 5mm (1/8") deep sheet of water 30cm (12") wide over a waterfall a flow of 3600 litres per hour (790 gallons per hour) is required. This flow will create a solid wall of water 30cm (12") wide, from 30cm above the surface without the falling water breaking up.
A standard open ended garden hose produces approximate 900 - 1100 litres per hour (200 - 250 gallons per hour).
The two most common problems experienced with these plants are rippling water and depth. Lilies do not like rippling water, it causes their leaves to initially darken around the edges, referred to as burning, and then slowly the whole leaf dies and eventually so will the plant. All varieties of lilies have a preferred depth, if the water is too deep then the leaves will struggle to reach the surface and the plant will die. With this in mind the plant should be located at a suitable depth even if this means putting on top of a plinth and well away from any fountains, waterfalls or filter outlets. If the pond is well stocked with plants and you have a limited number of fish then it would be worth adding a fertiliser tablet to the soil around the plant.
I would suggest, being new to fish keeping, the best sort of fish to start with would be Goldfish and Shubunkins. These fish are relatively inexpensive and hardy and will also add some nice colour to your pond. It is also worth introducing a few bottom feeding Tench, which will help clear up any uneaten food on the bottom of the pond. It is common for people to fill the pond up with fish when they first start, but Goldfish and Shubunkins will only grow to the space available. It is therefore, far better to stock reasonably minimally initially and then let the fish grow to a larger size than you would normally achieve. If your pond is large enough and as your knowledge grows then you could look to introduce a few small Koi, which are generally more expensive, but can add a wealth of beautiful colour to your pond.
When using natural rock in a pond environment it is advisable not to use porous rocks such as limestone or sandstone as these leech pollutants into the water and can cloud the pond and alter its chemistry, most commonly raising the pH reading. Non-porous rocks such as granite or slate are ideal for natural looking water features.
This is a frequently discussed topic in many aquatic centres. The problem is that unlike goldfish, Shubunkins and Saras Comets, Koi are bottom feeding Carp. This means that in the wild they would normally be rummaging along the base of a lake disturbing the sediment looking for food. This natural habit when transferred to a pond often means that Koi end up substituting the base of the pond with your planting baskets and a Koi of 30mm (12") can easily turn over a small planting basket. I have also seen Koi appearing to munch on lily leaves but on closer inspection they have been eating the snails eggs laid on the leaves. The fact that they were not eating the leaves didn't help the plant though. However, this is not always the case I have visited many ponds that have a few Koi in them and plenty of planting baskets that are not protected. To try to minimise the affect Koi can have on the plants you need to prevent them from getting at the soil and make the planting baskets heavier. This can be done in one process, placing large fist sized pebbles on top of the soil, or removing a few centimetres of soil and replacing it with a layer of lime free gravel.
Most healthy pond fish should have sufficient body fat on them during the summer months to survive for 2 weeks without being fed. Any longer means that some form of feeding is required. If you have equipment running (pumps, filters etc), then I would strongly suggest that you impose on a neighbour or relative to visit the pond ideally daily and certainly every 2 days. If this is possible then they can obviously feed the fish, but ensure they fully understand the equipment and how much to feed the fish. It is not at all uncommon for good intentioned neighbours to over feed the fish. If this is not possible then there are Automatic Fish Feeders which can be set up to feed the fish in your absence.
The intended inhabitants normally control the depth of a pond. Natural ponds intended for wildlife only, do not have a recommended depth, but because of the requirement for a beach (to allow the amphibians easy access) they generally start at nothing and run down to 450mm - 600mm (18" - 24"). Ponds intended for Goldfish, Shubunkins or Comets should have a reasonable proportion of the pond that is 760mm - 900mm (2\u00bdft - 3ft). Where as Koi should have a good area of the pond which is 1200mm - 1500mm (4ft - 5ft) deep. These depths are required to give the fish space to exercise and to prevent the pond from changing temperature too quickly as this can have a damaging effect on the fish.
Whether you require a treatment when topping up your pond is a frequent asked questions. If the water authorities were only using Chlorine in our tap water now, then there would be little requirement too use a Dechlorinator, however, they now frequently use Chloramine. The difference as far as the pond owner is concerned, is that unlike Chlorine, which will naturally dissipate in 7 days, Chloramine can last for 30 days. This means that if the pond is topped up once a week then the level of Chloramine can start to build up in a pond. If in any doubt use a Dechlorinatorwhich neutralises Chloramine should be used. If you have a filter system it is also a good idea to boost the bacteria colony at the same time.
Both options have their own merits and pitfalls. In general an above ground pond is harder to construct, but easier to look after and enjoy once constructed. During construction a raised pond will require less digging, but will require a double skinned wall (2 walls of bricks tied together). Therefore the project can be expensive and take longer to complete. On the positive side, once constructed a raised pond will be safer, because it is harder to fall in to. It will be easier to maintain, because the pond is it at a higher level, and it can be viewed more easily with built in seating or simply by sitting on the wall. Conversely raised ponds are more exposed to the elements, and can suffer more extremes of temperatures, which may affect the health of the fish. It can also be very difficult to locate and hide filtration equipment if required.
It is not common for fish to not breed, but far more common for the eggs and fry not to survive, particularly in densely populated ponds. This is because the adults will eat them either as eggs or as they grow over the next year. If you would like to ensure that the next generations of fish survive, then you need to catch the eggs success fully and protect them from the adults. The first signs that the fish will be interested in spawning are a few single fish being chased around the pond by several other fish. This is the female being chased by the males, although it can look cruel, it is required to help stimulate the female in to laying her eggs. Once they decide to breed, which will only happens 2 or 3 times a year, the eggs will be laid at dawn, almost immediately the adults will start eating them. You therefore need to use some sort of catching devise,such as a spawning brush, and install this when you see the fish chasing one another and then get up early for the next several days. Once they have spawned the catching devise needs transferring either to an aquarium or tub filled with pond water or a floating cage in the pond. It is important that the eggs are well oxygenated, and therefore if they have been taken out of the pond, an air pump should be used to oxygenate and circulate the water. If the eggs are being kept in a floating cage in the pond, then this should be located near a good source of circulation. When the eggs hatch the fry should be fed on specialised food or crushed flake food. They should be kept separated from the other fish for 12 months until they are large enough to hold there own in the competitive world of your pond.
Unfortunately, the old wife's tale of putting a tennis ball in to your pond to create an air hole is not particularly effective, because the ball can easy become frozen in place. However, there are several options available depending on your requirements and budget. The simplest involve the continuation of circulation, the insertion of a Pool Heater or Air Pump with a diffuser or simply covering a proportion of the pond.
This is a question we are asked frequently, the answer is very dependent on how severe a winter you experience. As a general guideline it is better to keep filtration running during the winter months, however, if you are in any doubt, switch the system off, clean and drain. The advantage of keeping your system running is that it is able to react to the change of temperatures with the fish and begin maturing earlier in the springtime, also as moving water will freeze at lower temperatures, it helps to prevent freezing over. The disadvantage is that circulating the system exposes the pond to the extreme temperature changes that occur in the air. If this results in quick and severe temperature changes in the pond, then the fish will suffer. To minimise the impact of this on the pond, any waterfall or fountain should be switched off or bypassed, the pump should be moved closer to the water that is returning to the pond and should be lifted up in to the top 1/3 of the pond. Should you choose to switch your system off then you should wait for two weeks after the fish have stopped feeding before doing so and should not feed them whilst the system is off. Most makes of filter pumps can be left in the pond, the filter should be cleaned and drained, the Ultra Violet should be drained and removed and stored indoors.
This is a very common problem with many older designs of fountain pumps. There are 3 options to solving the problem, the first is simply to replace the original foam prefilter with a larger prefilter which normally fits over the original cage which houses the foam. This increases the surface are that can be blocked and hence the time in between cleans. The second is to purchase a modern fountain pump which uses a fine cage instead of a foam prefilter, this will significantly reduce the frequency of cleaning. The third option is to install a filter pump, filter box and ultra violet light, which will take the waste out completely, reducing the debris which blocks the fountain allowing the fountain pump to do the job it was designed for.
The reason for the confusing is that there are two different kinds of Ultra Violet lights used in the aquatic industry. The first look like traditional fluorescent tubes, where as the second look more like the new style of low wattage house hold lamps and are described, and labelled, as PLS or PLL lamps. Both lamps emit the same Ultra Violet light but last for different lengths of time. The traditional lamps are designed to loose their efficiency after 6 months, whilst the PLS and PLL lamps loose their effectiveness after 12 months. The design of both styles of lamps means that the emissions of light gradually drop through the life of the bulb. The 6 and 12 month life spans are only guidelines from the manufactures, their will still be some light being emitted by the lamps after this time. If you have oversized your Ultra Violet then the light emissions may be enough to last longer than the manufactures recommend. As such there are two ways of deciding when to change your lamp, either leave it until the water starts to cloud or change the lamp no mater which kind, in the Spring so that the emissions from the lamp are at their highest during the Summer months.
I assume the reason for you interest in Low Voltage pumps is from a safety aspect. Low Voltage pumps are certainly as good as their counterparts in terms of their performance and can be easier to install. They are as a rule normally more expensive to purchase. Sadly though there is a limited range of Low Voltage pumps available on the market. As far as we am aware the only major manufactures of such a range is Oase, and they only offer 2 very large filter style pumps. However, provided a 230 volt pump is installed correctly, with suitable earthing and a good quality circuit breaker it should be as safe as a its Low Voltage equivalent.
If you are looking to buy an off the shelf filter then the answer is yes (sort of !!). All of the manufactured filters are designed to work on a certain amount of physical waste from a pond. If the filter is too large it is possible to starve the filter of waste and as such the filter will take forever (in pond terms) to mechanical "get going". To explain this, if you think of the filter foam as a sieve, the dirtier it becomes the better it works, because the holes are being partially blocked by large waste and so it is able to catch finer material. This is precisely how filter foam works. Most filter foam will easily start to block up with fish waste and once it becomes partially blocked finer material is caught. If you oversize the filter too much, then the waste is spread out over such a large surface area, that the partial blocking process takes possibly a year or even two, by which time you have become totally disillusioned and thrown the filter in the bin. When purchasing your filter I would not recommend buying anything more than 25% more than you really require.
It is not uncommon for ponds to be cloudy for up to a day after cleaning, if it takes longer than this to clear, then it is possible you are over cleaning your filter. A filter works best the dirtier it is, but does need cleaning when the water starts to overflow or bypass. So when cleaning a filter the aim is not to return it to a pristine condition, other wise very small particles may pass through the filter and cloud the pond. You should only clean 25 - 30% of the foam/matting/wool in you filter at any one time, leaving the remainder to continue to strain out the fine particles. When cleaning remember to only use pond water not tap water, as the chlorine in the tap water will damage the "friendly" bacteria in your filter.
The pressurized UV filter, along with most other pond filters, is designed to produce healthy and clear water, in doing so, it removes the green water algae that normally clouds the pond and produces Nitrates which are harmless to fish (in normal quantity's) and a food source for plants. Once the filtration system has cleared the pond, it will receive more sunlight and the green water algae, which has been removed, will not be absorbing the nutrients and sunlight that it had done before. This then enables other algae's, such as the weed (commonly called blanket weed) to grow. Blanket weed can be handled using different methods, such as water treatments or electronic blanket weed controllers.
Unfortunately there is no hard and fast answer to your question as it depends on the type of foam, the type of filter and the amount of cleaning required. Most manufacturers recommend that the foams be changed every 2-3 years. This figure is based on using genuine replacement products as many of the budget foams available are of lower quality than the original and would need changing more often.
Pond Fish Questions and Answers
There is a saying in fish keeping that people do not keep fish they keep water and the principle behind this is very true. If the pond water quality is good then this will help keep the fish in the peak of condition which helps them fight off infections and illness. To keep the water quality good you need to test it. The 5 tests we would recommend are Ammonia, Nitrite, Nitrate, pH, and temperature, to these could be added oxygen during the hot summer months.
Temperature is also important so that you know whether you fish should be active and interested in food or not, and because it has a bearing on the toxicity of Ammonia. It is not only worth testing for these readings, but it is also important to know what the results mean. We would suggest that the first test kit(s) you purchase give you clear information on what the results mean, and what to do about bad readings.
If the spots look like drops of wax on your fish then it is probably Carp Pox. Carp Pox is a virus, which is related to the cold sore virus that we humans experience. Apart from being unsightly it will do no harm unless it appears to close to the mouth gills or eyes and affects sight, breathing, or eating. It will lie dormant in the fish during the warmer summer months, but as the temperatures begin to drop the spots will begin to appear and will remain with the fish until the following year. Currently there is no cure for Carp Pox, however, we have come across many cases where after a few years the fish appears to have fought off the virus and it disappears from the fish. Like all viruses it is contagious and the other fish may become infected, although, it never seems to affect the whole of a pond's fish population at any one time. We believe that some manufactures are working on a cure, which may be available soon.
Pond fishes metabolism relies on temperature to enable them to digest food fully. If the temperature drops and the fish metabolism slows, as does their digestive system and any food left in their system will remain there and could start to literally rot inside them. As such, feeding fish during the winter months can be a very trickle business. If you choose to feed your fish you must be confident that the water temperature will remain suitably warm enough for several days after they have fed and you should feed Wheatgerm Foods, which are a specifically designed food to met the fish requirements at this time of year. If you are in any doubt it is better not to feed.
The activity you have noticed is called flashing, because the fish flashes its paler underside. This action can be an indication of a problem, because it can indicate that the fish have an irritation caused by parasites. The key to deciding whether parasites are causing an itch or not is the frequency with which they flash. If the fish flash once or twice in half an hour and then stops, it simply has an itch they need to scratch, if it's more frequent and continuous then they probably have parasites. If this is the case then the whole pond needs treating quickly to eradicate the problem.
