If you are searching “why is my pond green?” you are most likely looking for information about why it happened and how to fix it. This post covers
The only reason that a pond would turn green is because of algae that is growing in it. Firstly, algae in a pond isn’t always a bad thing. A thin, healthy algae layer on the surface is a vital part of having a good pond. It can prevent high levels of nitrates by consuming nitrates as food and putting off oxygen.
When Algae Is A Problem
- Whenever the healthy algae blooms, it will turn the water cloudy to green to where the water is so green that you can’t see into the water.
- Whenever you have the bad type of algae, called filamentous algae, it doesn’t always affect the color of the water, but it can grow in stringy masses or clumps to where it can overtake the pond.
In the situation where healthy algae has bloomed and turned your clear water green, here is what happened. The healthy algae that collects on the sides of the pond and never grows more than a fourth of an inch has decided to reproduce. Similar to a flower giving pollen, this algae will release millions of single cell algae. These cells are too small for a filter to pick up.
Controlling Algae Reproduction
So, how can you control the reproduction of algae? The best and efficient way is to install an UV light on the filtration system. The way that a UV light works is easy. As the water goes through the UV light it will be exposed to the light inside of the unit. The light waves are harsh enough that is destroys algae DNA, and kills it. Once the algae have died and starts to decompose it will begin to stick to each other. After the algae collects together, the mass becomes large enough for the filter to collect them or they go to the pond bottom. Once you have installed a UV light, the process takes about a week before the water is clear.
Stringy Algae
In the other situation, the pond water is clear but there are stringy algae all over and is rapidly growing throughout the pond. Algae becomes a problem when it breaks loose and floats around. Additionally, these algae will fill the basket and it will need to be cleaned constantly or it will stop the filter. This is due to filamentous algae. These algae introduced to a pond whenever you add plants. If a single spore is on a plant, it will create a problem.
The stringy algae can come in many forms. Some will grow slowly but some are fast growing and invasive. Some may not be obvious at first, but it will grow about 3 inches long on the pond walls. This type of algae will line your basket quickly to where it will affect the water flow but the basket has little debris in it. It is impossible for good algae to plug a basket as it is so small.
How can you control filamentous algae?
UV lights will have little effect on it because the algae grows on pond walls and never reaches the light. In mild cases, you can get the algae off the walls by hand when it gets ugly looking. In severe cases, it is best to use an algae control liquid. Algae Control is a great product that works well. It is a herbicide or weed killer. When dosed right, it is effective but you have to know how many gallons your pond is to use it properly. If you overdose the pond by 20% can kill your fish. It is suggested that you under dose the first couple of times that you use it, if you are unsure of how many gallons your pond is. 1-2 doses will normally kill the algae. It is recommended to use the half the dose every 2 weeks, instead of once a week as a maintenance. Keep your filter running to provide oxygen to your pond while treating because as the algae begins to decompose, it will take a lot of the oxygen out of the water. You have to pay attention when you use this product, but it is the most effective and easiest way to remove filamentous algae.
Tips about UV Lights
- Ensure that you have plenty of circulation in your pond. Is it circulating together? If you have dead areas in the pond where the water doesn’t move, then those areas will grow algae and as the water moves in the pond, it will cloud the water.
- Ensure that the UV light is sized for your pond. A light that is too small will not clear your water.
- Ensure that your filter system is going 24/7. If you are only using it part of the time, you could see that keeping the water clear is hard.
- The right sizes UV light with a good filter will clear your water all year without any real effort besides changing the lamp yearly. They work so well that it is recommended to never have a pond unless you have a UV light.
- Ensure that you don’t exceed the recommended water flow through the unit. If you send fast moving pond water through it, it shortens exposure time, which reduces the ability to kill algae. You may need to install a bypass for the lamp. This allows you to control how much water goes through the unit. Proper water flow is
- Ensure that you are changing the UV lamp yearly. After a year, many lamps are only work about 60% of capacity. The lamp could be on, but it may not have the ability to kill algae.
Pond Maintenance & Supply in Phoenix
If you have a green pond and need to get it under control we can do it for you, or help you choose the right products and tools to get the job done. We are a full service pond and koi pond company serving the entire Phoenix valley. We will help you maintain your pond, get rid of unhealthy levels of algae, and promote the overall health and beauty of your pond.
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