13/05/2025
Here is a question from one of our customers which you might relate to.
"I don’t have a very big pond, or that many fish, but every year I struggle to keep it clear. I’ve used a lot of pond clear products, but it always goes back to being murky, green and sometimes milky. What can I do?"
When you start seeing stagnant, murky water you’ve got serious issues, even more so if you are reporting to have seen it “milky” before. That milky colour is a classic indicator of Ammonia building up in your pond and it is the one thing we definitely do not want to have!
Starting from the beginning, do you have a pond pump AND filter adequate for your ponds total water volume? This is an indisputable must for anyone planning to keep and feed cold-water pond fish. While there are some ponds out there that can sustain good water quality without a filter and still have fish present, lacking a pump is a serious no-no. In this situation, and indeed any situation where you intend to feed your pond fish, you must have a pond filter. Think about all the food you throw into the pond for those fish? Without a filter what is supposed to remove that great additional load? As mentioned before, there are some ponds that can work in these conditions, but they are not recommended and certainly would not help in your current situation.
If you do not have a proper filter system on your pond, speak to a member of staff at your local Maidenhead Aquatics store. They will be able to advise you on the adequate system needed to balance your pond and start to remove those toxic waste products. If you do have a pump and filter installed but are seeing these sorts of problems, then there could be something drastically wrong with one or both parts of your system.
Check your pump and ensure it is fully functional, perform any maintenance needed like replacing impellers or clearing out protective foams. It is a common misconception that the foam found in pond pumps is a filter. While it is true that it will allow for the establishment of beneficial filtering bacteria, the foam’s true purpose is to act as a guard for the impeller. Small debris in the water could easily be sucked in and without the foam, damage the impeller or impeller well. Feel free to keep this protective foam clear with regular blasts from a hosepipe. Once you are satisfied that the pump is functioning properly and is powerful enough to properly circulate your pond, check your filter.
There are many different types of filters available these days, but maintenance on them is roughly the same. Firstly, and this is often overlooked by many pond owners, ensure that water is being properly fed into the filter. Breaks or blockages in the pipework, connecting pump to filter will hamper any attempt at a well-balanced pond. After ensuring that the filter is being well supplied by the pump, it wants to be fully cleaned and inspected. Please note, unlike the protective foam around the pump, the foams and filter medias in the filter can only be safely washed with pond water or dechlorinated tap water. Often pond owners can have problems with water quality by cleaning filters too regularly with the hosepipe, this actually causes the problem to persist and even worsen. The best idea is to simply take a few buckets of pond water and hand rinse the filter foams in that. At this point you can assess whether the foams need replacing or not and also check within the filter for any kind of internal blockage. Once again it must be noted that a filter that is too small for the ponds total volume will not run efficiently, even with a large pond pump. Do ensure that pumps and filters are properly matched to the ponds they are destined to support.
If you see to the above issues, you should hopefully start to see a quick improvement in the pond, but do remember that a pond might take 2 or 3 weeks to properly balance out. Think about adding a bacterial booster product such as “Pond Bomb” by Evolution Aqua. This will kick start your filter and help clear your water. If problems decrease, but continue to linger, check your UV filter, if you have one, make sure to replace UV bulbs once a year. Perhaps you may be feeding too much? Or have too many fish? Try reducing the food entering the pond, or feeding only once a week. If you still have problems past this point, you will have to look to remove and rehome stock to match the biological boundaries as dictated by your pond and it’s associated filter system.
If you have any questions or concerns about any aspect of your garden pond or pond fish, please pop into your local Maidenhead Aquatics store and speak to one of our friendly team who will be glad to help!
