Instructions
Check out the GPH (gallons per hour) number. This is perhaps the single most important thing to know about an up-flow pump. If the filter makes the water flow too quickly, your system can fail. If you choose something that flows too slowly, you end up with a mucky pond of sludge. Make sure to find the right size for your pond. In general, you want to filter your pond at least once every 2 hours.
Get a good warranty. It's important to check your up-flow filter often to make sure that it's operating properly; if not, send it in to be repaired. By choosing an up-flow filter with a good warranty, you can protect yourself down the road from having to pay for costly repairs.
Choose the right biological media. Different types of filters have different stuff inside to clean out your pond. Some have foam filters seeded with bacteria; others have beads or plastic media. Some may also include features like UV lights to help keep your pond at optimum health.
Find out if you can bury it. Some up-flow filters are designed to go underground for aesthetic purposes. If this is important to you, check whether it applies to the model you want.
Check the price tag. A good filter costs $200 or more, depending on its features, so shop around for the best deal.
How to Buy Up-Flow Filters for a Koi Pond
When buying a filtration system for your koi pond, there are several different directions you can go. When it comes to out-of-pond filtration, you have either an up-flow filter or a down-flow filter. If you're looking to buy an up-flow filter for your koi pond and let gravity do all the work, there are certain things that you need to look for.