Everybody wants a healthy, aesthetically pleasing garden pond all year round. Our guide provides key tips to maintaining your pond and what you should be doing throughout the year to keep your fish happy and their pond well cared for.
Garden pond maintenance
Here are our top 10 tips to maintaining a healthy, clean and aesthetically pleasing garden fish pond:
Cleaning Your Pond
Keeping your pond clean is a task which should largely be completed by your filtration system; however, additional tasks must be completed to ensure that your pond is immaculate.
The first task on the list is ensuring your filter is in good working order and therefore working efficiently. Depending on the type of filter you have, this task may vary; but you should undertake a deep filter clean if required, washing sponges and/or biological media in spent pond water. Any ‘consumable’ media, such as filter floss, should be disposed of and replaced if required.
Important Note: You should never clean any media under chlorinated tap water as this will kill good nitrifying bacteria.
Routine Filter Cleaning
If your filtration system isn’t overly soiled, then a routine filter clean is in order. In doing so, you should look to remove 10% of the pond water and replenish with clean, dechlorinated water. Routine filter cleans should be completed weekly during the warmer months and less frequently in the winter months.
If using a UV clarifier, check the unit is working. There should be an indicator light which will glow blue if everything is in order. It is important to replace the lamps in the UV clarifier every 12 months.
These lamps begin to lose efficiency after around 6 months therefore, the ideal time to swap a lamp for a fresh one is in the spring when the weather starts to warm. By doing this, you will ensure the UV is working efficiently throughout the spring and summer months.
Manual cleaning can be done on the pond with a fine mesh net, which is ideal for removing surface debris such as fallen leaves. In addition to this, pond vacs can be a useful tool for removing any debris which has settled on the bottom of the pond.
In order to do this, the pond vac should be set up as per the instructions. You should then take time using the nozzle and head provided to hoover up the sinking debris.
Finally, algae brushes can be used to clean water features and fountains. You should use the head provided to scrub the fountains, ridding them of green stains.
Algae is a pest plant which occurs in ponds in several different forms and species. The first and most prevalent form is a single-cell, free floating algae which often makes pond water resemble pea soup. This is one of the most common issues people have with their ponds. Fortunately, it is relatively straightforward to resolve.
Algae is a plant and when the sun makes an appearance and the temperatures warm, it begins to bloom. This will not harm the fish. In fact, fish actually feel at home in green water (providing the quality water quality is good), but I think I speak on behalf of most pond owners when I say we prefer our pond water gin clear.
As we like to say at Complete Koi & Aquatics, water quality is for the fish, water clarity is for you!
UV Clarifier Algae Treatment
The most effective treatment for green pond water is without doubt, a UV (ultraviolet unit) clarifier. This will give you guaranteed results and is safe for ALL wildlife. The UV clarifier works by killing microscopic algae cells in the water as it passes along the high intensity light.
For ponds which already have these installed and are experiencing green water, we would expect the UV lamps to have failed over winter and will ultimately need replacing. In extreme circumstances, the whole UV unit may have several issues and require fully replacing.
Improved water clarity is normally visible within 2 weeks. Once you are on top of the problem and have added or changed the UV lamp, the pond should continue to run clear until the UV lamps fail again. We would always recommend getting the largest UV you can fit, as this will continually provide you with the best water clarity results.
Chemical Algaecide Algae Treatment
Another effective way of treating green water is to use a chemical algaecide treatment such as Cloverleaf – Green Water Answer Chemical Algaecide. This does however, come with associated risks.
The Green Water treatments are effective and whilst they are safe for general wildlife, they do have adverse side effects on available dissolved oxygen within the water. This is a requirement of your fish, so if you do choose to go down this route, it is imperative that you use an air pump and air stone during the treatment.
It is always best to avoid using chemicals where possible, so use this as a last resort. Ensure you measure your pond volume accurately and apply the correct dosage. This will NOT cure the problem in the long term and instead will simply postpone the next bloom.
As if pea green water wasn’t bad enough, in Spring you may also begin to see a green, hair-like structure zealously growing from the depths. This phenomenon is caused by blanket weed (also known as thread/hair algae) which can cling to ponds, fountains and water features, bellowing up into the water as a green scum.
Spores of blanket weed can blow in on the wind or may arrive on the feet of birds, but it is the increased levels of both sunlight and temperature which cause this plant to bloom.
A little blanket weed is to be expected from time to time, and this can normally be taken out with a plastic rake. For persistent amounts of blanket weed, we would always recommend an enzyme-based treatment such as Cloverleaf – Blanket Answer.
This treatment is safe to use with all aquatic life, including pond fish such as Goldfish and Koi Carp. The treatment is combined with existing pond water and added back into the pond or koi pool in specific quantities. The activated minerals and enzymes will immediately get to work in destroying blanketweed blooms.
Initially, the water will turn cloudy white, though this will generally persist for less than a week. It does not require UV clarifiers to be turned off during this time and within a month of treatment using Cloverleaf, ALL blanketweed should be eradicated. Blanketweed treatments are unfortunately not permanent solutions and may need reapplication several times a year.
Maintaining Pond Plants
Pond plants need similar levels of care to their terrestrial counterparts. You must follow these steps below to keep your aquatic plants in tip top condition:Firstly, pond plants should be sufficiently fertilised. This may be in the form of pond fertiliser sticks which can be used periodically. Alternatively, pond plants which have been sitting in the same substrate for several years should be re-potted to replenish the nutrients which plants require to grow.
If repotting, you should carefully remove the plant and its root system from the old pot. A suitably sized, new pond plant pot should then be lined with a hessian sheet before repositioning and filling with aquatic compost. Once this has been completed, we advise scattering a layer of gravel over the top of the soil to stop large amounts of matter leaching out.
It is good practice to then submerge this in a bucket of water prior to placing it in the pond to dislodge loose substrate which may otherwise cloud your water.
This may sound obvious, but pond plant roots must be kept wet. This doesn’t pose an issue if your plants are in the margins of the pond; however, if your plants exist in boggy ground surrounding ponds, it is vital you keep this ground wet in the warmer, drier months. Failing to do so may well result in fatalities for certain, more delicate species.
The best way of doing this is manually watering any dry areas with a watering can or hosepipe. Also providing some level of shade can stop the ground drying out as quickly
The final step in keeping your pond plants looking good is pruning. We advise pruning pond plants as and when they need it. Remove any dead leaves by pulling off or snipping with secateurs. Likewise, when blooming has finished for any flowering species, we also advise removing the flower heads.
We do not want any dead plant matter in the pond if we can help it, as it will require the filtration to work that bit harder. For aquatic perennial plants, such as marsh marigold, these can be cut back as the weather cools to prevent dead matter entering the pond.
If you follow these simple steps, your plants should look great all year around. Aquatic plants should be researched prior to purchase to ensure they will be compatible for your pond conditions.
Maintaining pumps, filters, and fountains
Pumps, filters, and fountains all require some level of maintenance occasionally. The top and bottom of this is that they need to be kept clean and free of debris which could cause issues.
Maintaining Pond Pumps
For pumps, this usually entails removing the cage-like casing (if wet mounted) and washing to dislodge any trapped large solids.
While undertaking this task, you should check the impeller can move freely, as the likes of blanket weed or moss can sometimes get wrapped around the impeller shaft. This can restrict or even cease flow completely through the pump. If this is the case, you should remove the inner casing and free the impeller of any potential waste.
Important Note: Whenever you are working on a pump, please ensure that the power is disconnected.
Maintaining Pond Filters
With regards to filters, maintenance can vary, but this should all start with routine filter cleans which will depend on the type of filter you have. These routine cleans should be undertaken frequently in the summer and less frequently in the winter.
For deeper filter cleans, it may be worthwhile stripping the filter down and ridding it of any large, unmovable debris and sludge. Any detritus which the filter cannot break down or move on could possibly cause ammonia/nitrite spikes which could negatively impact fish health.
Maintaining Pond Fountains
When it comes to maintaining pond fountains, there is really not much to it. Depending on the type of head you have on the fountain, you may need to dislodge any detritus with a thorough wash under a powerful tap. Of course, it is possible to use enzyme-based products which can naturally aid in reducing debris in the pond.
Examples of this are:
- Cloverleaf Blanket Answer, designed to tackle blanket weed / hair algae.
- Cloverleaf Sludge Answer, designed to tackle pond sludge and smaller detritus.
Controlling pond aeration and water movement
These are essential bits of kit in the warmer summer months when natural gaseous exchange is insufficient. By installing an aeration kit in your pond, you will ensure that the fish have ample amounts of oxygen to breathe.
Water movement can also aid gaseous exchange, and this is best achieved with fountains and or waterfalls. Fountains and waterfalls are achieved by using pumps. Fountains generally come as a kit, where the pump and various attachments are included. Examples of these are:
- The fountain pump range by Bermuda
- The Power Jet fountain kit by Laguna
Water is pumped via these to the top of a waterfall or a water blade, which can be purchased or built. The water turbulence created by a fountain or waterfall will also aid filtration as the additional water movement will help eradicate dead spots in the pond, pushing any waste to a bottom drain or pump/filter
Watching out for leaks
Leaks should be monitored in ponds by keeping an eye on the water level. Leaks can occur in a number of places, including the pond liner/lining, pipe work and waterfalls. When you experience a leak and your water level is dropping, it is important to diagnose the cause of the problem quickly.
Leaks in Pond Liners
In order to do this, pumps should be turned off to identify whether the pond liner is leaking. Please note: fish need oxygen, so it is advisable during this period to aerate the pond with an air pump. If the water continues to drop while the pumps are off, then it is most likely the liner which is split and is causing the leak. The water should be allowed to drop (within reason) to the level of the leak so you can identify the problem zone and make amends. It may be possible to repair the area however, in certain instances, a full relining may be required.
Leaks in Pond Pipework or Waterfalls
If the pond does not drop while the pumps are off, we can assume the leak is coming from pipe work or a waterfall. Spend time checking the pipework over on a dry day. Any areas which feel moist may well have split. This is a typical issue in winter when frost damages the flexi hose. This can drain a pond very quickly if the pond is pump fed, so it is vital you catch these issues early.
To reduce the chances of this happening, flexi pipe work should be lagged with pipe lagging to improve the temperatures in the pipe. If the pipework is all sound, then we can finally assume the leak is coming from a waterfall or water feature. Closely inspect any waterfalls or water features for splits and/or tears in the lining or structure.
Monitoring water levels
Monitoring water level in a pond need not be a difficult task. You should use a marker point in the pond, such as a planting basket, to mark on the pond liner/fibreglass or an overflow pipe to understand where the water level should be. Any deviation from this may be down to extreme weather (hot or wet) and should be corrected accordingly.
If the pond is too full, due to exceptional amounts of rain, water should be removed to stop the pond overflowing. This is best done with a permanent overflow i.e. a pipe which allows water to run off the pond when it gets to a certain level.
If the water level is too low, this could be down to a leak or alternatively due to hot weather causing evaporation. It is important to identify the route cause before refilling. Ponds should be refilled slowly with dechlorinated water. This can be achieved with a chemical water treatment such as Chlor-Go by NT labs or alternatively, an inline dechlorinator such as Evolution Aqua Dechlorinator.
Monitoring water temperature
Water temperature should be monitored using a floating pond thermometer. Understanding the temperature of your pond is very important as it affects fish health and behaviour.
In cooler temperatures, below 8°C, Koi will often stop feeding. Between 8-10°C, Koi must be fed an easily digestible diet of wheat germ. Anything warmer than this and you can begin to increase the protein within the Koi carp’s diet.
Ponds can also get too hot, which can hamper gaseous exchange, starving the fish of oxygen. Above 20°C, ponds should be kitted out with an air pump to pump oxygen into the water. Additionally, there should be plenty of water movement via waterfalls, fountains and returns.
Monitoring water quality
Water quality should be monitored on a weekly basis. This is done with a quality water test kit such as pond labs water test kit by NT labs. This test, and other similar tests, will allow you to check:- pH
- General Hardness (GH)
- Carbonate Hardness (KH)
These are all important parameters when it comes to fish keeping. For Koi, you will ideally be looking for the following:
pH: This should be kept between pH 7 – 8.
Please note: pH has a direct correlation with KH.
Ammonia: This should be 0 in a healthy, established pond.
Nitrite: This should be 0 in a healthy, established pond.
Nitrate: This does not have an impact on Koi health however, a high nitrate can result in pest algae, so this should be as low as possible.
General Hardness (GH): Koi ponds should have hard water; therefore, the GH should be kept above 120 degrees.
Carbonate Hardness (KH): This has a direct bearing on water pH, and by ensuring our KH is above 120 degrees General Hardness, we can guarantee the pH will stay steady between 7 – 8 which is ideal for Koi health. If KH drops to 0, it is possible to experience an acidic pH which can result in a filter crash and can cause Koi health problems and in some instances, fatalities.
We advise all our customers to start testing early as a form of preventative maintenance. If we understand our pond's water parameters, then we can look out for any deviations before they become problematic. It is our duty as Koi keepers to look after the water which the fish inhabit.
Dealing with Pond Parasites
The most important seasonal check you can do on a pond is checking for parasites. Parasites generally come and go with the seasons as they prefer warmer weather.
During the winter months, our fish go into a form of hibernation, whereby their metabolism slows down, and they often stop eating. Coming out of winter, fish are generally weaker and more vulnerable. As a result, they become ideal targets for fish parasites such as Costia, Flukes and Trichodina.
We advise all our customers to undertake fish health checks in spring to eliminate the possibility of parasite outbreaks. This is done by taking a sample of the fish’s mucus on a glass slide and looking at it under a microscope. This does not hurt the fish.
If this is something you do not feel comfortable undertaking, the staff at Complete Koi & Aquatics can perform the relevant fish checks on your behalf. Likewise, we recommend the same checks in early Autumn to ensure our fish go into the cold winter months in fantastic health.
Fish Health and Water Testing
Additional to microscopic level checks, fish should be visually checked frequently. We are looking out for any damage or signs of bacterial infections which could negatively affect fish health.
Water quality should be monitored throughout the seasons as per the previous paragraph. Any deviation from the correct parameter readings should be interrogated to find out the cause. Again, water testing is something the staff at Complete Koi and Aquatics can assist you with.
Pond maintenance with Complete Koi & Aquatics
If you have any further questions on how you can maintain and care for your garden pond all year round, don’t hesitate to get in touch with us. We offer fish health check and water testing services to help aid your pond maintenance.
Give us a call or pop over to see us today.