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Frequently Asked Questions
- How can I control excess waste that feeds the algae?
- I am having a party and I would like to clear my pond in a hurry. How can I settle out the green water?
- How often do I need to replace my filter media?
- How often should I clean my filter?
- What should I do about the string algae in my waterfall and pond?
- Why is my water green? How Can I Solve the Problem?
There is only one bit of advice for this problem: stop feeding your fish so much! Over feeding of fish is probably the most common way water turns green. Also, remove dead or dying foliage from plants in and around the pond before they settle to the bottom. Decomposing plant matter feeds algae, causing green water.
Clearing the water in a hurry, whether for a party or to enhance mechanical filtration, can be done using a flocculent. It is a liquid that is added to the pond, doing its' work in a few hours. The material, sold under the name of Accu-Clear, causes suspended particles in the water to stick together. This makes the larger particle heavy, causing it to settle to the bottom of the pond. When using a mechanical filter, these heavier particles can be removed from the water easily. This product should not be used as a substitute for healthy, balanced water. It does not kill the algae, it only makes it drop to the bottom of the pond. In a few days the water will again be green unless the algae is killed or filtered out.
Filter media that is in the form of a filter pad should be replaced when the original shape is flattened or is limp. The loft of the material should be similar to how it was originally. If the material is clogging sooner than it used to, it should be replaced. Most biological filter media pads last two seasons because it is not washed often enough to harm the material. Pre-filter media that is used for mechanical filtration wears out faster because it is being washed often. Filter media in the form of plastic tape or bio-balls will last for many years and only needs to be cleaned periodically to keep it fresh.
|Biological filters should be cleaned only when the flow of water coming from the pump is hindered by the clogged filter. The filter is harboring beneficial bacteria which is keeping the water clean by taking nutrients out of the water (algae food). Once a reduced water flow is noticed you should clean the filter media in the following manner. The biggest mistake most people make when cleaning their filter is to clean it too much! You should take your filter pads out and slam them on the ground, on your grass preferably (the nasty smelling stuff coming off the filter pads is great fertilizer!) Slam each pad down enough times to loosen the muck so that it comes off the pad. Once the pad gets lightweight then it is ready to go back into the filter. DO NOT pressure wash the pads. They will get too clean. DO NOT use tap water from city or county water on the pads. The chlorine in the water will kill the bacteria on the pads and you may actually have greener water after cleaning because the pads have to build up bacteria again before they can naturally clean the water. The hardest thing to do will be for you to put a pad back into the filter that still LOOKS dirty. But do it anyway! You will have better success if you will not wash off all of the bacteria.
If you are lucky enough to have filter media that looks like strapping tape, just take it out of the filter and shake loose the muck. Again, you should not wash the media, just shake it good and put it back into the filter.
If you have a biological filter box without a drain in the bottom of it, you will need to shop-vac it out once a year or so when the bottom of it gets too full of sludge.
Filamentous algae (the fuzzy or stringy kind) is a beneficial type of algae that harbors good bacteria necessary for clearing the water. The trouble with this type of algae is it is unsightly when it grows long in the streambeds, waterfalls, and along the sides of the pond. A short layer is good for the pond, but when it grows to two or more inches, it is often considered to be too much. Fish will usually take care of the string algae in the pond itself. On the waterfalls and streams, hand weeding removes the longest parts sufficiently if done every couple of weeks. Several products including algaecides, barley straw, or barley extract promote string algae control if used on a regular basis. Also, pH should be checked when there is an excess of string algae. If pH is too high (over 7.5 or so), the bacteria that generally would out-compete the algae for the nutrients in the water will not grow properly.
Water is usually green because of floating algae. Algae need three things to live: sunlight, air, and nutrients. Algae live off of organic waste in the water, which comes from fish waste, decaying plant material, decayed bugs, and other stuff that naturally falls into the pond. If you have an overload of organic waste that is not efficiently being removed by aquatic plants and beneficial bacteria you will have algae. Too much fish food, decomposing leaves, pollen and dust can contribute to the abundance of nutrients. Anything organic turns into fertilizer for algae as it decomposes.
Adding plants to your pond will not only add beauty but they will help to combat algae. Their nutritional requirements are the same as algae and roots from the plants will take a lot of the organics out of the pond. Floating plants such as hyacinth will help greatly as they have large root systems that hang right in the water eating up the algae food! We also recommend adding water lilies to ponds which do not have an abundance of big koi in them (big koi eat lilies). Lily leaves should cover approximately 60% of the surface are of the pond. The leaves provide shade, which will help to keep the algae in check. There are other benefits to adding lilies such as beautiful flowers and cooler water but these are for another FAQ!
Another requirement for clear water is beneficial bacteria. Well-colonized bacteria will out-compete the algae for the nutrients in the pond. Many factors contribute to the inability of the bacteria to take care of excess nutrients. A new pond may not have enough bacteria established to efficiently remove nutrients. Given time, the problem will take care of itself. Or you can add bacteria to jump-start your colonization. Once the bacteria deplete the nutritional value of the organic matter, the water clears up quickly, often overnight. Beneficial bacteria need something to cling to and to grow on. Biological filters, stream beds filled with rocks, and AquaMats can provide the space for bacteria to colonize.
We recommend regular applications of live bacteria. Bacteria can be added in a powder or liquid form. Beneficial bacteria will naturally inhabit your pond but you will get a better rate of growth of the bacteria if you will add it to the pond.
A high pH prohibits the natural bacteria from growing properly. The pH should be in the range of 6.5 to 7.5 for normal growth of bacteria. High pH often contributes to green water and excessive string algae growth.
Lastly, there are algaecides for the pond. These products are chemicals and should be applied following label instructions closely. An overdose of algaecide can cause fish and plants to die. However, some people swear by algaecides for their ponds, especially for string algae.