Pond Health

Ask a gardener about his or her pond health and they will uncannily resemble a proud parent with a plethora of setup and in-situ photos on their mobile devices. I wanted to say slideshow carousel but then I would be showing my age.

We labour over our ponds, like parents, because we know our work will pay off when our gardens are graced by their irrefutable beauty. However, unlike raising children, there are easy guidelines that help, from conception to maintenance, look after and manage our ponds without too much aggro, angst, or door slamming.

Primarily, keep your pond healthy. A pond’s ecosystem can be detrimental to your health and the surrounding environment if poorly maintained. We recommend you follow a seasonal-based pond health plan:


Winter has been and gone; aquatic life wakes up from their long hibernation and daffodils raise their heads to remind you it is time to de-winterise your pond and give it a good old-fashioned ‘Spring-Clean.’

Add to your checklist:

Check your equipment

Take it all out, give it a deep clean, check it is working as it should, and fix or replace any parts that need attention. An effective and cost-efficient aeration system will help maintain and keep your pond clean throughout the year. It also increases oxygen supply by keeping the cooler water on the bottom of your pond which helps keep your fish and aquatic life happy all year long.

Feed your fish!

They are going to need feeding but do not overfeed. The best time to begin feeding pond fish after winter depends on how warm the water is. When your pond water rises above 10°C, you should give them food once a day. And, as soon as the water temperature reaches 21°C, begin feeding them their regular amount – make sure you have researched the right amount for the number and size of your finely finned friends.

Clean until it gleams

There is a reason we need to spring clean our homes as well as our ponds. Over winter we let things accumulate, like leaves, twigs, grass clippings, fish waste, etc. and so too will your pond! Even though your filtration system will have been working over the winter some of that waste will turn into sludge and muck, verily, a party palace for algae. Do not worry, by using EM Mud Balls, an anaerobic system, the sludge can be broken down simply and easily to support your pond health.

This is a deep clean so you will need to drain the pond and wash the pond base and rocks. If you have waterfalls – they do too. Remember to transfer your fish and aquatic plants BEFORE you begin cleaning to a large vessel with proper aeration. You know someone, somewhere, has forgotten to do that!

Those with installations that include a bottom drain or bare bottom system will not need to drain clean the pond.

Next – once clean and free of debris and scum simply refill your pond and introduce back your fish and plants.

Keep your aquatic plants well-fed

You have fed your fish, do not forget to feed/fertilise your plants too when putting them back in the water. Feed them according to their recommended dosage and needs i.e., full fertiliser for new plants and maintenance for your existing ones.

We recommend Aegir seashell grit, which is rich in calcium. Plants LOVE calcium. Aegir seashell grit also helps with your pond’s pH levels. The seashell grit can raise the pH slower letting the pond settle easier into the changes.

Adding beneficial bacteria

To keep your pond properly maintained, add beneficial bacteria for good bacterial colony stimulation after you have cleaned your filters to remove accumulated sediment. Actiferm will help with this, however, be careful if you have fish, start with 1 litre per metre3 and see how the water pH reacts. A sweet spot is 5.5


Your pond LOVES Summer. Your pond will positively THRIVE in Summer. The summer season begins when your pond water temperature hits a steady 20°C and higher. Feed your fish generously during these balmy days, however, there are a few things you should be aware of:

Algae love Summer too so try and keep your pond free of grass clippings, fish waste, and other debris. If this happens you may need to adjust your nitrogen and phosphorus levels. Use a test kit to check your levels. You can buy these online or from your local aquarium retailer.

If there is too much algae in your pond, the effect of Effective Micro-organisms can be enhanced by adding EM Pond Clear Super Booster.

EM Pond Clear Super Booster contains a high concentration of phototrophic bacteria that competes with the algae. This is also beneficial to fish as a food source. Phototropic bacteria can use the extra nitrogen to break the proteins down to help with the C:N ratio in the pond.

If you want more information on managing your algae levels visit: https://buddendo.home.xs4all.nl/aquarium/redfield_eng.htm

Top tip:

Add Aegir Seashell Lime Calcium Carbonate if your pH is low. The carbonate component raises the alkalinity in your pond; high pH is alkaline and low pH is acidic; a pH level of 7 is considered neutral.

Start with 250g per m3. The carbonate component within Aegir Seashell raises the total alkalinity and the buffering daily fluctuations in pH, increasing microbial activity in the pond soil, and the availability of phosphorous to phytoplankton. Pond water with a total alkalinity of less than 20 ppm can benefit from liming.

Visit: FA38/FA028: The Use of Lime in Fish Ponds (ufl.edu) to delve deeper into liming.

To reduce your nitrate, add Barley Straw to your pond. Once the straw bales are wet, a natural process starts that combats algae growth. This process is enhanced by the inclusion of lavender which gives significantly better results. Simply add 1 straw bale to ponds up to 1200 gallons (5455 Litres).


Keep on testing

Keep testing your water, especially at this time of year. Like Summer, your pond will need debris removal, especially as the autumn leaves start to fall. You can prevent falling leaves from entering your pond by installing a pond cover or using a floating pond skimmer.

During Autumn, your marginal plants may start to die off. Prune or remove dying plants as soon as you see signs this has begun. For living plants, cover them with polythene or an insulating horticultural fleece to protect them over the winter months ahead.

Your fish will need less food

Your fish, during this time of year, will need less protein-based food. They will have eaten and stored plenty over the summer months ready to survive the winter months with these reserves.

Medicate your pond!

Parasites and pathogens lay dormant during the winter and attack fish during the spring when their immune systems are weaker. Actiferm will help with this, however, be careful if you have fish, start with 1 litre per metre3 and see how the water reacts.


When the temperature drops so will the heat in your water. We recommend switching off your Ultraviolet Clarifier because icy water is not a healthy habitat for Algae, and they will simply die off, which is what you want! However, keep your pump running, and here is a tip; elevate your pump from the base of your pond to allow more space for your fish to rest where the water is fractionally warmer!

By keeping your pond health ‘healthy’ thoughout the year you can enjoy 365 days of pondaliciousness [made up word], get out your camera and add to your growing album(s) on social media – it would be rude not too.