Water Feature Q & A
Q: I have a 1,000 gallon pond and already the string algae is starting. I am sick of constantly cleaning it. Any ideas? – Steve of New York
A: Like Steve many of you find yourselves in this same situation, where it seems like you are battling algae year after year with no end in sight. The thing I want you to know is that in order to fully understand how to control algae, you really have to understand how it develops in the first place.
The Key Ingredient:
One of the key ingredients for algae to grow is a food source (aka Nitrates). And I’ll have to say in almost every water feature that has a bad algae problem, it is the abundant fish load that is causing the issue. So why does an abundant fish load cause algae? When fish eat they over time, like every living creature, will have to excrete the waste (aka ammonia). This ammonia, when filtered properly, will breakdown into nitrates (aka food source). Make sense so far? This food source is then eaten by algae. From there some of the algae will be eaten by the fish and thus the cycle, the nitrogen cycle of life, begins again.
So the bottom line here is: If we have control of the food source (aka Nitrates), we have control of the algae. I have mentioned this before in the past, but it bears repeating.
Keep Fish Loads to a Minimum:
I know you love your fish and this is a touchy subject. But if you plan to have sixty 12″ koi in a 1,000 gallon pond, your going to have an algae problem and it won’t be inexpensive to get a hold of. When calculating your fish load think of it in pounds of fish or total inches. For example, one 6” fish can weigh as much as four 4” fish. The number of fish will affect the overall fish load, although 10 small fish may only produce the waste of one large fish. With this said, remember that your fish are growing and in many cases multiplying. Always plan for the future and be careful not to overstock your water feature.
The size and type of your filtration system will depend on your total fish load. If your filter is not properly sized for max potential, your fish will outgrow the filter. When this happens, ammonia levels can reach to lethal levels. In most cases filters on the market are rated for ponds containing no fish or a minimal fish load. It is always best to get a filter that is rated for at least 2x the water volume of your pond.
Aquatic plants and algae will compete for the same food source in order to grow. I don’t know about you, but I would much rather see a few beautiful water liles then green slime. A simple rule of thumb is to have 60% plant coverage. This should consist of submerged, floating and marginal plants. Floating plants, such as Water Hyacinths & Water Lettuce, are fantastic at pulling nitrates from the water. I recommend putting a few into your waterfall filter box if you have one. Rooted plants, such as water lilies and marginal plants, create a great place for your fish to hide from predators. Please note when aquatic plants are not present, algae will take their place. See our selection of aquatic plants here.
Beneficial Natural Bacteria :
I’m sure you hear this a lot nowadays as to why you should be adding beneficial natural bacteria to your water feature. The reason is because it is another reducer of nitrates. One product to check out for this is called the DefensePAC. It is a combination of five products that provide beneficial bacteria, trace minerals, and a fish and plant safe pond cleaner. The DefensePAC works to breakdown fish waste, leaves or other organics that accumulate in the pond. These are essential to maintain a clean, clear and healthy ecosystem. The best of all, one DefensePAC lasts up to 6 months for a 2,000 gallon water feature.