reprinted from Koi Club of San Diego Newsletter
#1. The gunk at the bottom of the filter stinks. It's mucky, it's slimy and it smells like a stagnant pond. But plants love it because it's already pre digested for them and you are likely to have the greenest, healthiest garden in the block when you dump the muck on your garden.
#2. Pea Soup Green water is not very esthetic when you want to show off your fish. All you can see are shadowy shapes moving through the water and you might as well own all white ogons as that expensive red and white kohaku or nifty brown chagoi if you can't see anything but pea soup murk. But the green water is actually quite healthy for the fish. It offends our sense of esthetics, means we cannot see the disease on the fish early, and creates a great deal of competition with the fish for the dissolved oxygen in the water. However, newly hatched fry thrive in it, it shades the water and keeps it somewhat cooler and it is definitely a deterrent to blue herons. What they can't see they won't get. The hardest bit about pea soup green water is waiting long enough for the pond chemistry to balance, the filter to take charge and start breaking down the raw fertilizer the fish and their decomposing food create.
#3 The water in your pond is pond water. You do recall those fascinating biology slides in High School with all the unicelled organisms swimming around and eating each other? Guess what is in your pond water swimming around eating each other. But this is exactly what carp live in. The majority of those organisms eat each other, not the fish, some even provide food for the newly hatched fry or other things that provide food for the fish.
# 4. Nobody has a perfect pond and all the answers. Everyone will give you different answers for the problem you are asking about. If your fish are ill you can buy medicated food, make your own, inject them with drugs or dip them ahead of time for immunization. Which should you do? It depends who you talk to. The koi community is probably one of the friendliest groups you will encounter, because although everyone has their own favored filter type, they are willing to share and demonstrate to you why that one is right for their situation, but might be wrong for yours. The answers are out there, as well as a lot of experience, some of which is bound to match yours and have a hard won answer to your problem.
#5. Koi are carp and carp, like puppies, eat what ever they can get in their mouths. You need to be protective of what gets available to them making sure guests and children don't dump their sodas in the pond or throw in copper pennies. But along with eating everything, it also means we can treat them with a varied diet -- the left over watermelon from the picnic, the half a grapefruit from breakfast, a quartered head of cabbage because it is so darn cheap at St. Patrick's day.
#6. The Spawning procedure is a very violent brutal experience. The males almost literally batter the eggs out of the female, leaving bruises on everyone who participates -- which is usually the whole pond. It is literally a dirty happening with the pond full of scum from the milt and the thrashing. Crystal clear water becomes murky with stirred silt. But the experience of finding a fingerling or two in the pond that you know you did not purchase and that turns out pretty nice makes up for the temporary dirty house.
#7. Fish are slimy. Snakes are smooth and dry and slick, but fish are slimy. When you catch them for the show or to medicate them, they are slick slimy wiggly creatures. But that slime coat is part of their protection and design. One of the indications of fish health is the consistency of the slime coat. Adding salt increases the slime coat on our fish and increases the fish's resistance to external parasites.
#8. Serious fish breeding means culling. Culling is sorting through the 250,000 eggs that hatch out of the 500,000 that were laid and fertilized and discarding the baby fish. But as cruel and inhumane as it sounds, culling ensures the strength of the baby fish you do keep. You are initially discarding the deformed fish, then the ones with non desired color patterns. You are also ensuring that as those baby fish grow they have adequate space in which to grow and a better chance at the food. A pond that is adequate for twenty large koi quickly becomes inadequate for 100,000 baby koi.
#9. The pond is likely to contain all sorts of strange animal life right along with your fish. Leeches, anchor worms, fish lice, mosquito larvae, you name it. They're the big brothers to those unicelled creatures you looked at under the microscope. But most of those critters provide food for the fish or, if they are not eaten, are easily controlled with a dose of Dimilin before they get out of hand. Snails seem to come out of thin air whether or not you have introduced plants. Dimilin knocks them down as well, although the fish like escargot as well as they like caviar during spawning season.
#10. There are no guarantees in Koi keeping. That beautiful baby fish you bought that was a glorious platinum white and metallic yellow is as likely to fade to a dull white as he is to remain bright and exciting. A fish that was bought as a dynamite red and white kohaku, faded in poor water and was brought back again. But that rather strange little fish is just as likely to change into something really wonderful as it is to change into something ugly. "Tategoi" simply means "a fish with potential." Not "Instant champion, just add food and time."
#11 A properly set up pond will need constant upkeep and attention. But consider just why you put it in the first place. Attention becomes part of the pleasure of koi keeping. There are obligations such as sitting by the pond feeding the fish and observing them for a while each day, watching for disease and bruises and potential problems. A properly designed pond is like a good car, upkeep can be minimal most of the time with occasional major tune ups and filter changes once or twice a year, depending on the fish load.
#12 Fish die. Usually the one you are the most attached to, paid the most for, or was a special gift from a special friend. But please try and keep some perspective on the fact this is just a fish. An expensive fish, a beloved fish, but not a child. Your fish will not be covered by your HMO and most likely your vet will give you a polite turn down when you call him. Fish are remarkably hardy healing creatures, healing fins and sores frequently without showing a scar. And sometimes they die for no apparent reason or from quite apparent raccoons or blue herons. There will never be one quite as special as that one, but please recall that koi, unlike Macaws, usually do not insult us by outliving their owners.
#13. Fish grow. Another unsettling fact for those who have stocked their pond to capacity with 8 inch to 15 inch fish in June and can't figure out why their pond is full of green water the following June after the winter. The more you feed Koi, the better the chances they will grow large. But unlike a house with too many children koi do not grow up and move out. You will have them with you forever. You can't abandon them along the side of a country road, you can't release them to fly away, they're your responsibility. Now they've grown and you've been both lucky and skilled enough that none died over the winter. Over crowded ponds are unhealthy for the fish and stunting to growth. Find a friend with a pond. Donate one or two to the meeting raffle.
#14. Koi swim in their toilet. Yucch. But with an adequate filter system that toilet can be flushed and purified hourly or better. How fast does your pump recirculate the water? That toilet water is the same stuff that is nourishing the algae on the sides of the pond that provides food.
#15. Algae is invasive. Pea soup algae, hair algae, velvet algae on the side, brown algae, scummy algae, all sorts of algae. A brand new pond will have no algae. Everybody else's has algae. But that algae, as with the pea soup clouding, is good for the fish. Hair algae is the fine stringy stuff floating out like hair in he water, attached to the sides, the filter inlet, the waterfall, everywhere. Koi generally don't get caught in it and it is easy enough to pull off with hands or pool scrubbing brush. The second year my pond was in operation I had a strong growth of the hair algae. I put up shade cloth, allowed the fish to grow (lots) and the next spring the hair algae growth was minimal. The koi ate the little that sprouted. They also snack on the velvety coating that is all over the side of my pond. Another reason I don't worry about them missing a meal as they have plenty of veggies.
#16. It is probably not possible to feed your fish without getting splashed. But a good deal of the pleasure of watching the koi is seeing their enthusiasm over food.
#17. Koi and plants mix with caution. But it can be done and done well. Koi, like pigs, like to root. They are not rooting to munch on your prize water lily roots, but they will break off the new growth and cloud the water with the disturbed soil. If you want to have lilies with your koi fill the top of the lily pot with large rounded river rocks that are too large for your koi to move. And keep your koi population down. Think about a marginal planting area where the fish are isolated from the plants by a barrier or dike of some sort, allowing the water to flow from the pond to the plants, but too shallow for the fish to navigate.
#18. Koi are expensive. Undoubtedly at some point the one fish that catches your eye will be more expensive than your house payment. But with careful shopping and a knowledge of what constitutes a good fish you can find smaller "tategoi" at a great price and have the pleasure of raising them to that larger size.
#19. No matter how large your pond is constructed, it's never large enough. It is a Koi enthusiast axiom that the minute the pond is finished and filled you want a bigger one, while you're planning the next excavation, you still have this one to enjoy.
#20. Truly disgusting is probably being able to tell your co-workers that you're going to HAVE to go home and talk to the fish, or spend your vacation watching the water lilies bloom. In these lazy summer days could a pond be any more irritating (to others) than that? Talk of relaxing and peaceful