Q&A for How to Build a Pond Filter System

You can always attribute algae in a pond to the sun. If you want to get rid of the algae but you don't want to kill any fish or anything, get an algaecide that's safe for fish and it'll work just fine. In the spring and summertime, you almost always get an algae bloom, which is totally normal. Don't freak out about those blooms, just use a dose of the algaecide and you'll be fine.

I put my submersible pump inside an upside-down plastic mesh waste basket (from the Dollar Store), then wrapped the outside of the basket with nylon window screen. Over the course of the summer I typically have to remove the screen twice and rinse it off with a garden hose. This keeps the pump intake from clogging and reduces the number of times the filter media has to be changed as well.

You can add Bio-Balls, Bio-Rings, carbon packs, rock and sponge pads, which you use in your aquarium filters. You must layer them on top of each other.

Yes, they can. But consider more plants than fish, as they will eat some of the plants.

Use 5-inch schedule 40 PVC white pipe, dig a trench on the side of the pond to the height you want the water, use 5 sections of 10 feet long pipe and drain it off into a lower area.

It depends on how fast you want to pump that 300 gallons and how high. Read different pump specifications to see their rated GPH (gallons per hour) and pumping heights.

Yes, that is the intention, this filer system is not recommended to be placed inside the pond itself. But the pump that pumps water into the filter must be kept in the pond at all times unless being cleaned (must be turned off for this), to avoid the pump burning out.

Just use a piece of screen door screen over the hose end, secure it to the hose with zip ties or picture framing wire after covering the screening with pantyhose from a dollar store.

You just need to rinse the filtration media with pond water.

They can't be made. They are usually bought and used to break down fish waste.

Build a bigger filter or get a smaller pump or water line. A smaller pump will save you money, but a bigger one shouldn't overflow.

You need to have a pump to circulate the water. Otherwise you will have a pond with stagnant water.

Yes, this method won't cause any problems for ducks or other kinds of wildlife.

It will most likely overflow, and your pond will probably become dirty.

It is not advised, especially if it gets hot where you live. It will just not be good for the fish and will draw mosquitoes.

You would put some of the pond water into a bucket and wash the filter material in the bucket of pond water. This way you clean off the bad bacteria but keep the good bacteria that is in the pond water already.

No, unless you are willing to clean it out daily. It's meant for typical fish excrements and plant debris, not mud. A hose mister might be more of what your looking for.

Plastic soda bottle caps, Bio bale, and scrubbies work about the best as far as household products. Cut up PVC or CPVC also works.

That completely depends on the size of pond. The boxes will tell you what you need. You can buy these pumps from any hardware store.

As long as you are able to keep the filter bucket above the water line, then yes. This pump method requires gravity, as well as the pump, to keep things flowing. Make a pretty display by decorating the filter bucket and its accompanying riser to match the surroundings, such as putting a shallow bird bath bowl atop the bucket as an additional feature.

If the water does not freeze, then yes. If your temperature goes below freezing, you may want to introduce a pond heater to keep the water flowing.

Yes you can use gravel in this fashion, but the bacteria (aka bioslime) which develop around the gravel will fill the voids and plug the water flow. A plugged flow will prevent the filter from working and this will create anaerobic conditions in the filter (which you don't want) and water will back up. Alternatively, plugged gravel may lead to the flow channeling through the gravel so that the bulk of the water is untreated by contact with the bacteria. The finer grain the gravel, the faster these conditions will develop. Washing the gravel will reduce the density of the bacteria and open the voids so that water can flow through. Bacteria density will once again increase.

Generally, yes. You'll need a filter for your fish pond to control algae growth, oxygenate the water, and remove waste. Especially for ponds with goldfish or koi, a filter system is super necessary to get rid of all of the biological waste and contaminants.

A good rule of thumb for pond filters is to have one that can handle about 1 1/2 times the number of gallons of water in your pond. For example, if your pond has 100 gallons (378.5 L), then you'd want to have a filter rated for 150 gallons (567.8 L) per hour in order to be sure the filter can handle the volume of water.

There are 2 types of pond filter systems that are commonly used: mechanical and biological. Mechanical filters work by using screens to filter the water and capture small particles so the water is clear. Biological filters use a material that attracts bacteria and allows them to live inside of it instead of the pond.

Maybe your bucket’s lid was too tight. Try with a different container with a looser lid.