Portfolio » Large Pond Clean and Filtration Installation, Congresbury, Nr Bristol

A Large Pond Filtration System Installation, Pond Clean, Pond Repair  and Aquatic Planting Improvements at the Double Tree by Hilton Hotel at Cadbury House


This commercial pond project involved the installation of a pond filtration system and pond improvements via an aquatic planting plan, full pond clean and flexible liner repair for this commercial client.


Large Pond Improvement Project Specification:

The existing large pond was very dirty, had green water issues as well as low water and looked uninspiring and uniform.

The clients wanted to achieve clean and clear water within a more natural and visually pleasing pond where they could enjoy viewing a small number of Koi carp.

The Commercial Pond Improvement Action Plan:

The green water and dirty bottom are a result of overstocking with fish, both Koi and Goldfish. The fish create waste  which feeds the algae causing green water and they stir up any waste on the bottom creating dirty water. The pond shape has a large surface area and shallow depth. This allows it to warm up in sunnier months boosting algae growth rates. The lack of plants mean that the algae has no competition for the nutrients it uses as a food source. The lack of shade allows sunlight to penetrate the surface of the water allowing the algae to photosynthesise. This algal growth creates green water.

Firstly the pond must be prepared with a full pond drain, clean and a liner repair. Next, the filtration system is installed, fish stocks are reduced and finally a heavy planting plan is implemented to add shade and further filtration with a few additions to improve the look of the pond.

Commercial Pond Clean:

To address the water quality issues we drain the pond and clean it out. Once the pond is clean it will be far easier to keep clean in the future. Firstly we divert and stop any inlets and then pump the pond water to waste ground where it can drain away. The overstocking of Goldfish and Koi carp are netted and placed in temporary storage for re-locating.

The waste that has accumulated within the pond over time must then be removed. This waste consists of fish and bird faeces, dirt from run off, wind-blown and inlets and leaves and plant matter, which has blown in to or died and rotted within the pond. This is usually made up of a green to brown silty layer with a consistency that varies depending on how wet it remains. This waste can sometimes be pumped to rough ground depending on its consistency. In this instance we had to remove it by hand using buckets.

Once the pond has been cleaned we can carry out our improvements to keep it that way.

Commercial Pond Repair:

Once the pond was cleaned we could expose the faulty seam and repair the flexible liner. We cleaned all along the seam and pulled the extra piece of liner closer to allow an overlap. Seaming tape was run along the length and heated in to place to create a good seal. The joint was finished with a further flexible mastic seal to hold the liner edge down.

Commercial Pond Filtration Installation:

The first improvement is a modern filtration system: The pond has a large surface area to depth ratio and therefore requires a considerable level of filtration. With this in mind the system we chose, consisted of a four part system with each quarter of the pond served by an individual filtration system. Each individual system includes two feed pumps, a large filter box with automated waste separation and a large ultra violet (UV) unit. The system runs on 50mm flexible pipe allowing pumps to be re-positioned and minimising friction losses within the pipework. Each unit is separately wired and can be isolated for maintenance and cleaning. The filter boxes have drains for running waste directly to the near-by vegetation. All the filtration equipment installed in this system is low energy consumption. The pumps can be individually remotely controlled to adjust flow in relation to water temperature. The UV units can be manually set to a percentage performance or set to Economic (Eco.) mode allowing an automated response to water temperature and prolonging bulb life span whilst further reducing energy consumption. The filter boxes themselves only require a small amount of energy to maintain an efficient level of cleaning. At this stage we begin to re-fill the pond with clean tap and rain water. We add water conditioners to ensure that optimum water quality is created for the returning fish.

Commercial Pond Planting Plan:

With the filtration system installed we can move on to the aesthetics of the pond edges and implement our aquatic planting plan.

Plants improve the ponds aesthetic appeal with the variety of colours and shapes provided by the leaves and flowers of many different species. The plants have the added function of providing additional biological filtration helping to clean and purify the water, they offer shade to the water helping moderate sunlight penetration and water temperature and they provide shelter and habitat for wildlife both within and around the pond. We used a combination of planting techniques to help with the look of this pond. Along the back and in several spots around the pond we positioned pre-planted rolls to add marginal plants to shallow areas. In some instances we back filled with pebble to allow further marginal planting. At one end we created an Iris and Reed bed. The bed is separated from the rest of the pond by a rough stone wall which retains the pebble planting media. we added a lot of areas of potted Lilies to create islands of colour and shade in the sunnier seasons. Finally we spot plant marginal aquatic plants around the edges under the turf and add small piles of rock to break up the line of the bank.

Finishing touches:

Along side the on site maintenance team we planted some large laurels and mixed shrubs to help disguise the filter units. The on site team also applied camouflage netting covers to further aid in this. We hand sort the fish and return a low stock level of quality Koi and the excess are re-located on site.

Commercial Pond Filtration System Installation Complete:

The project is completed and the Koi carp are visible through the clear water enjoying their new full, clean and improved pond. The water is undergoing filtration and the plants are providing shade and additional filtration. The reduced fish stock means the load on the pond is reduced. All in all a successful project which was a pleasure for us to undertake and can be enjoyed by the Double Tree by Hilton Hotel Bristol South – Cadbury House clients, guests and staff for years to come.

If you have a large or commercial pond project and need a professional design & build service please contact us here at Aquaflora Landscapes to discuss your options. We are based in Bristol & Bath and cover the surrounding areas as-well-as one-off projects far and wide. We supply and install new pond liners and repair existing damaged liners, design, supply and implement aquatic planting plans and improvement projects and design, supply and install commercial and large-scale pond filtration systems.