Koi Ponds

There are 2 types of filters, biological filter and a mechanical filter with some filters actually being 2-in-1.  Mechanical filters filter out debris and algae from your pond.  Biological filters help break down pollutants and toxic ammonia from fish wastes and turns it into useful nitrates.  If you want a clear pond that isn’t murky and full of debris, you should use a mechanical filter.  If you have fish, frogs, etc. you will additionally want to have a biological filter.  If you don’t have a biological filter your precious fish that you expected to live and enjoy will most likely die from toxic ammonia.  These are some reasons why you should have a filter and what benefits each of them bring to your pond.

A biological filter is a filter or a living environment where beneficial bacteria live.  This can be a filter, lava rocks or other fish safe media.  The purpose for a biological filter is to provide an oxygenated environment where beneficial bacteria can live and thrive. These bacteria are responsible for breaking down and converting toxic ammonia from fish wastes into nitrites and then into harmless nitrates.  The beneficial bacteria are essential to any pond.  You can add live beneficial bacteria like Microbe Lift  in a liquid form to your pond to “jump start” the biological filtration system so your pond is equipped to handle fish.  An important note to consider regarding biological filters is that chlorine kills the beneficial bacteria living there.   So, if you have to add tap water to your pond, it is best to de-chlorinate the water first before adding it to the pond.  You do this by simply letting the water sit for about 3 days. (Other ideas are to spray the water up in the air from the garden hose and let it spray down into the pond.  This helps to evaporate the chlorine in the water before the water hits the pond.  Another idea is to run the tap water through some Activated Filter Carbon  which will help to dechlorinate the water before it enters the pond.  You can cut out a hole in a bucket and put the Super Activated Filter Carbon in a media filter bag and tie the end so the Super Activated Filter Carbon doesn’t float out into your pond.  Next, put the garden hose into the bucket and the water will pass through the bucket and exit out the bottom and into your pond.  Make sure that the flow of water going into the bucket doesn’t exceed the flow exiting.  If so, adjust the flow of water from the garden hose or make the hole in the bucket larger.)  One other idea that I personally find as a “must” to have around the house is having Ammo Lock 2 .  This product when added to your pond will instantly neutralize the chlorine and chloramine in the tap water (as well as lock the ammonia if your ammonia levels are high) so it is not absorbed by the fish.  Once the water is filtered through your biological filter, the beneficial bacteria living there will break down the ammonia into useful nitrates and break down the ammonia in the water.  Ammo Lock 2 is good to have around as it can really bail you out of a situation in case you’ve been too busy or have forgot to check your ammonia levels and all of a sudden one day your ammonia is high and your fish are dieing or acting kind of funny.  Ammo Lock 2 will instantly neutralize the ammonia and you most likely will be able to save your fish.  Another thing that improves the function of a biological filter as I mentioned earlier is  barley straw bales.  They improve the function of your biological filter and help reduce algae, especially the long, unsightly string algae in the heat of the summer.  It lasts for months and is totally organic and chemical free.  I have some in my pond.  Try it.

This is a pretty broad question since I don’t know the type of fish you have nor the size of pond.  A rule of thumb is to feed a koi fish that is about 6″ long about  6-10 pellets of Fish Food in the morning and night.  If you have a large pond that offers other things for your fish to “nibble” on, you may never have to feed your fish.   A very important note about feeding fish is not to overfeed them.  When you do feed them, your fish should come to the surface of the water and gobble up the food within a minute or so.   If it’s left there for several minutes or longer, your fish are not hungry.   It is better to have slightly hungry fish than to have fish that are full all the time.  It’s kind of like being a “couch potato” ( I have to add a little humor to these faqs! :o)) and munching all day long versus a person who is active, gets some exercise and eats moderately.  Who do you think is the healthiest?  Besides the health of the fish, by overfeeding them you naturally increase the amount of wastes they excrete and it puts more demand on your biological filter to break down the toxic ammonia from these wastes into harmless nitrates. Your water can stay cloudy too, and you’ll wonder why.  If you’re feeding them too much, your filter may not be able to compensate and essentially your ammonia levels will go up and your fish may die.  You may just have continuously green water too, as the nutrients from the fish wastes are providing nutrition to the algae.  So either way, don’t overfeed your fish and test your pond water approx. once a week to check it’s ammonia and other chemicals.

This answer really is a matter of personal preference.  If you have a small pond and don’t have any fish in it, then yes, you can empty it or leave the water in it as you had.  If there is no reason to have pumps running, etc. I would remove the pumps, statues, etc. and just leave the water in it.  You will probably want to clean it and add fresh water to it in the Spring so it doesn’t matter what you do with it now.  If, however you have fish in it, your pond should be at least 30″ deep and have a Pond Aerators and Pond Deicers for the fish to stay outside during the winter.  (We have complete information about Winter Fish Pond Tips.)

An important note to consider about keeping fish outside during the winter is the size of the fish and if they are native to cold temperatures.  If you have small koi – approx. 4″ long and not much fat on them, they just may not make it outside for the winter and you take a chance of losing them.  Fish need a certain amount of fat on them to insulate them from the cold temperature and a koi fish that small may not have enough fat.  Mosquitofish on the otherhand, while only about 2″ long at maturity can withstand the cold temperature because they are native to cold temperatures and they can have plenty of fat on them at even 2″ long!  (Plecos on the other hand, may not survive the winter in your pond because they are native to warmer temperatures.)    We have been asked many times about the possibility of keeping fish outside in ponds that are shallower than the recommended 30″.  An idea that you can try is to have a submergible pond de-icer as well as a floating pond de-icer but it will depend on your pond size as to how many you need.  This is done purely at your own risk of losing the fish.  The pond de-icers are thermostatically controlled and set so the water doesn’t actually freeze but will not heat your water above freezing (above 40° F).   Technically, your fish should be where it’s a bit warmer but if this isn’t feasible then having a submergible de-icer and floating de-icer may be your only option unless you have a nice neighbor with a large enough pond to “babysit” your fish for the winter.  You can always bring them inside for the winter.   Just make sure they have some type of aeration system whether it’s an aerator or a pump and biological media for the beneficial bacteria to grow on.