FishProfiles.com Message Forums

Hey everyone.

I have approximately a 2000 gallon pond. I am wondering how strong of a pump I need as I want to create my own filter box with an overflow back to the pond. Also, how strong of a UV light do I need and how should this all be set up? I am pretty new to this. Thanks in advance for your help. My pond is pea green soup now. I would like to fix this as soon as possible.

First determine how often you want you want your pond to turn over, or how often it will take your pump to circulate the pond's total volume. You're looking to be somewhere between once ever 3 hours to twice every hour. Theoretically, a 2000 gallon per hour (gph) pump will turn over your 2000g pond once an hour. Now you have to factor in filter and plumbing back pressure and water head height. A filter can reduce your flow rate from 10 to 25 percent. For every 90 degree elbow in your plumbing you will loose 1-2 gph. Head height is the vertical distance from the pump to the highest point it is pushing water in the plumbing. Different types of pumps have different flow rates in relation to the head height. Waterfall pumps have a high flow rate at high pump head height, but use a lot of electricity. Circulation pumps tend to have a low ratio of flow to head height, but they use less power. The packaging the pump comes in should have a flow rate chart detailing its flow ratios. So, a 2000 gph pump would realistically turn over your pond once every hour and a half to once ever 2 hours
Youll need a UV sterilizer of at least 25 watts. They come packaged with charts showing how many watts you need at what flow rate for how many gallons you are sterilizing. Keep in mind that green water is usually a symptom of to much waste in the water and to much sun. Limiting the direct sun exposure to the pond and upping the filtration can greatly reduce if not eliminate green water saving you the expense of a sterilizer. Adding water plants can also help by creating competition for the nutrients in the water.
I would run the pump output through a jandy valve to split the flow between the filter and sterilizer. This will allow you to have high flow to your filter while having the proper lower flow to the sterilizer. Hopefully I haven't been to confusing.:%)

adding better filtration is a quick fix but the cheapest way to cure and prevent green water is pond cover. you need to have atleat 30% of the pond covered and most of the time they need more. then if the green water wont go away i would try a uv sterilizer. as there pretty expensive