A sea of green Controlling algae in troubled waters
If your water turns a murky green, the first thing to remember is, don't panic! The second thing I want you to know is that no garden pool is ever completely clear and algae-free. Indeed, algae is part of the ecological balance. A small amount, visible as a slightly green (or bronze) cast to the water, or as a coating that forms on the sides, is both normal and healthy. That said, algae gets out of hand at times.
In the early days of a new water garden's life, there's inevitably a flush of algal growth, called a bloom. This bloom occurs because plenty of light is available, not to mention dissolved nutrients to nourish it. Small or shallow water gardens are the most vulnerable because they heat up faster, and algae love very warm water. Wait it out. As your waterlilies spread their pads and other plants grow and contribute to the desirable two-thirds coverage I mention throughout this chapter, the algae should subside.
If a smelly pea-soup prevails, you do have a problem, but you also have options. Diagnose the cause, and then take steps to treat it:
- High water temperature: Algae prospers with warmth. Add more plants, particularly floating plants, which can out-compete the algae for minerals dissolved in the water. Provide extra, cooling shade, such as a large beach umbrella overhead in the hottest part of the day.
- Excessive fish food: The food the fish don't get around to eating breaks down in the water, adding to the organic broth. Fish waste and its byproduct ammonia also encourage algal growth. Try feeding fish less ("only as much as they can consume in 5 minutes" is the rule) and/or take out some fish. Install a filter to help remove fish waste. Treat the water with a liquid ammonia remover (such as Ammo-Lock); follow label directions with great care.
- Excessive nutrients: The source may be runoff from your adjacent garden or lawn, or perhaps you're overfertilizing your water garden plants. Cut back on the fertilizer and/or create diversion and drainage channels to keep runoff away. Keep yellowing and fading plant parts trimmed off (don't let them break down in the water). Also, make sure leaves and other lawn debris doesn't end up in the water.
- Improper water pH level: Buy a simple kit and test (first thing in the morning is the best time to check). It should be between 6.5 and 8.5, ideally around 7.0. Adjust with water garden chemicals as necessary (get the products and advice from wherever you got the test kit).
You can use your bare hands to remove algae, but understand that hauling out algae is a temporary solution. It can make your display look better for a while, but if you don't address the cause, more will soon replace it.
Was this article helpful?
The Secret of A Great Lawn Without Needing a Professional You Can Do It And I Can Show You How. A Great Looking Lawn Doesn't Have To Cost Hundreds Of Dollars Or Require The Use Of A Professional Lawn Care Service. All You Need Is This Incredible Book.
Get My Free Ebook