Aug 2002 20th Anniversary Year Selected Articles

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From the President to the N. F.K C. Members: 

Well our next event is the summer party. This year we are going to have a Japanese theme. We will have a Picture show of Joe and Sherri White on their Japan trip to purchase Koi. We are also going to be voting on the Pond of the year from our Pond tour. Don’t forget, the dinner meat will be provided, by the club and the drinks also. If anybody knows of a Japanese type dish please bring it in keeping with the Theme. Till we meet again, Tim Gasson

 Secretary's   Report By Todo  Tim called the meeting to order at 2:00 PM with 43 members and guests in attendance. After the Treasures and Secretaries report were delivered and approved, Tim explained that the board was deadlocked on whether to have a second Pond Tour in Sept. or not. The discussion touched on how much money the pond tour has brought in in the past, what it will take to mount another show, how much it will cost in money, time and effort. In the end Tim called for a vote and the pond tour idea for Sept. did not pass.

The caravan trip to Black Water Creek Fish Farm on Aug 17th was discussed. Members were advised to wear hats that give a lot of shade as there are few trees on the farm and the August sun will be hot.

The club took delivery of four 8 foot tanks to add to our other thanks for the koi show. AFKAPS will be at the same site as last year though the show tank setups will be moved out of the center of the hotel. The dates are March 20-23, 2003.

Todo talked about the Koi Health Advisor program the AKCA is running. He said the club had received a letter telling us we could have three members train as KHA. Todo and his wife Sandee had been approved for the program last year when it was first announced, but the club needed to fond another member to fill the third slot. The only stipulation was that the KHA could not be in a koi related business. Jim Roberts, Dave Brown and Anne Miller all volunteered for the post. In the end Dave Brown got the nod.

Our next meeting will at the Doctor’s Lake Estates Civic Center on SATURDAY Aug. 10th.

Managing Your Disease “Odds” By Hugh Mitchell, D.V.M. Licensed Veterinary Medicine for Your Koi Reprinted from Washington Koi and Water Garden Society Newsletter, via Mid-Columbia Koi & Pond Club.

At a recent talk, I tried to put forth the concept of disease as being more than the result of an encounter of the fish with a pathogen (bacteria, virus, or parasite). A more accurate way of viewing disease is to see it as a complex combination of factors about the fish, the pathogen, and the pond environment which come together like “the ingredients in a recipe.” These factors work in concert to produce the specific “flavor” of a malady - each disease with its own complete set of fish, pathogen, and pond environmental factors, without which disease cannot happen!

This means that disease IS NOT A RANDOM EVENT! It happens for a reason, and the secret to keeping your fish disease-free is to recognize the set of circumstances that produces a particular disease and do what you can in your pond, and with your fish, to minimize them.

This is easier said than done. In fact, another fish veterinarian from the U.K. puts it quite nicely when defining what fish medicine is all about: “Diagnosis and treatment are often quite straightforward but the underlying (pond) management problems need to be corrected as well.” We call these “pond management problems” risk factors. They come from the same three things.

Old Pond Syndrome By Todo

I remember the time I asked my mother what “The straw that broke the camel’s back” meant. Just a simple explanation would have sufficed, but Mom tended to the theatrical. Narration as she went, this ample Polish woman hoisted bundle after bundle of imaginary straw onto a fantastic gargantuan camel. Soon the poor beast would take no more and collaped in a heap, crushed spine and all. This image visits me every time the subject of Old Pond Syndrome (OPS) comes up.

OPS is the term for an established pond that suddenly falls apart for no apparent reason. Ponds easily accommodate normal environmental changes that fall within their range of health equilibrium. And, as long as the pond keeper is vigilant, this equilibrium can be maintain indefinitely. However, if not watched closely OPS can sneak up and destroy the pond.

As ponds mature subtle changes occur that have a profound effect on the pond’s well being. Fish grow. Filtration, adequate when fish were small, starts reaching its neutralization capacity when handling more solid waste and more ammonia. Aeration becomes inadequate as bigger fish require more oxygen. Parasites and bacteria, held off by the fish’s own immune system, become problematic as water quality deteriorates. A pond can teeter on the edge of disaster for sometime, waiting for that one event that will break its back

Pond crash triggers come in many forms. Even innocuous events may be enough to tip the balance: power outages, disease vectors like introducing an un-quarantined fish or diseased plant, ammonia concentration creeps up until it damages or even kills the filter, a cold snap or warm spell, going on vacation. The list is endless, but once OPS takes hold many fish are likely to die before that pond returns to balance.

A few Saturday’s ago a fellow called with a fish emergency. His koi had stopped eating three days before and developed some skin condition. My first question was, had he introduced any new fish in the past few weeks? He had, a small koi bought three weeks before.

Visiting his pond the next day exposed his real problem. He had 30 fish, some as long as 28 inches in a pond not quite 1000 gal. and only 28 inches deep. In short he had too many fish and too many big fish for his system. He was also under-filtered, under-aerated and had been feeding catfish food instead of a proper koi ration. His pond was balanced on the knife edge of an OPS crash and the introduction of an un-quarantined fish pushed it over.

No matter what we did to stem the tide of death, the vast majority of his fish died within a week. There is an old koi keeper’s adage: ten percent of your fish will survive any disease, but this is small comfort when the dying fish are yours.

The best way to deal with OPS is to avoiding it in the first place. This is not difficult provided that you do periodic water testing, maintain a proper fish load for the pond’s volume and filter, keep the pond and filter clean, encouraging algae growth on pond walls, introduce plants to the pond environment, feed properly and frequently observe your fish so if something changes you will see it.

What is a Hospital Tank?  Why would I need a Hospital Tank?  How does it work?

A hospital tank is a place that we heal our sick fish without infecting other fish or subjecting the other fish to medication.  A hospital tank is needed to help fish that may otherwise die if left in a regular tank or pond.

A hospital tank serves several functions:

1.Heal Fish

a.Higher than normal temperature.

b.Higher than normal salt percentage.

c.Special medication (**!!!warning do not medicate fish without first talking to a fish treatment specialist or your veterinarian. Fish illness can be tricky business. Misdiagnosis can make the situation worse and hurt or kill your fish!!!**)

2.Quarantine fish

a.Quarantine fish that you think may be sick. This will protect your healthy fish.

b.Fish that are new to your area (pond/tank) should be quarantined for at least 24 hours this will help you to ensure you are not bringing unhealthy or potentially sick fish into your fish population.

How to help your hospital tank work more efficiently.

Higher temperature helps speed up the metabolism of the fish. Because they have more energy to move, they have more energy to heal.

(Not too hot, about 75 degrees is ideal.)

Have one or two strong air stones to help add oxygen to the water. This will give your fish the air they need to live and fend off anaerobic (bad) bacteria.

Higher salt percentage in the water helps kill unwanted bacteria, be sure not to over salt the water (Koi are fresh water fish).

Koi In Summer

I would like to start with a short presentation to give us all some background on aspects of handling koi in hot weather and then we’ll open this us for general discussion and a Q&A session.

If you wander around on the koi chat sites online you find that the concern about how to deal with koi in the winter starts up in September. However, here in Florida winter is our easy season. Aside from Spring, the touchiest time in the koi pond is, Summer.

Summer means heat, for us and for pond water. Though water has a substantial thermal inertia by late May or mid-June the water temperature is pretty warm. My own pond, before it was shaded, water temperature hover between 85F and 90F all summer. The shallower your water the higher its temperature can climb which implies that proper pond design can have an effect of the problems of summer. Other things that we have to watch are: ammonia levels, they are more toxic as water warms; water carries less O2 in summer; fish metabolism is increased in summer meaning higher O2 demand; bacterial respiration doubles with each ten degree rise in temperature which also puts higher demands on oxygen; pH levels are effected by all summer stress factors. In view of these potential problems almost any minor disaster can trigger a major pond emergency.

One of the best ways to reduce the effects of summer on your fish is to cover your pond. In preparation for this report I took the temperature of my main pond and the temperature of a small quarantine pond near by. My pond is covered by a pergola of thick vining plants and the tank is open to the sun. In the hottest part of the day the main pond was 8F cooler than the quarantine tank. 8F is a change of about .8 mg/L in Dissolved Oxygen, (DO) which we will see is a great amount.

In addition to keeping the sun off your pond and in-ground pond may be cooler due simply to the heat sinking effect of the ground. Greater depth also plays a part in keeping our fish comfortable as does more volume. These are things to think about if you are building a pond, but what do you do with what you already have?

First and foremost is aeration, aeration, aeration is the key. You have heard me say before that there are two things you cannot do; one is filter too much and the other is aerate too much. This goes triple in the dog days. It is now time for us to shift over to a discussion of Dissolved Oxygen, because in the end DO is the 800 lbs. gorilla of summer pond problems.

Please do not feel insulted, but I feel it important to point out that fish do not "breath" water. They process water over their gills where free oxygen dissolved is removed and enters their blood stream. So the amount of DO in the water directly effects the immediate welfare of the fish.

Oxygen gets into the water in several ways. If you run plants in your pond or have any type of algae including green water and string algae than a by product of the plant’s daytime respiration is gaseous O2. However, the reverse happens at night and the plants take O2 out of the water at night. This the reason the lowest DO levels occur just before dawn.

Even without any vegetation O2 infuses at the air-water boundary. In short at the surface of your pond. This happens all the time, even in still water. But, even a light wind can cause ripples that may effectively increase the pond’s surface area by 2 or 3 times and the more surface area you have the more O2 you transfer. When we aerate it is the air-water boundary that we manipulate.

I’m going to get a little technical here, so bare with me. One Liter of pure water at 0C is said to be saturated (normal DO level) when it contains 14.6 mg of O2. This is about as good as it gets in the DO world as there is an inverse relationship between water temperature and DO levels. The hotter the water the less DO it can contain. At 25C (77F) the DO saturation drops to 8.2 mg/L, and at 92F it is half of what it held at its best or 7.3 mg/l. This is the reason that we never worry about DO levels in the Fall, Winter and Spring. The water is cool and holds plenty of O2. Interestingly, altitude and atmospheric pressure have little effect on the oxygenation process so, we gain no advantage living so near sea-level.

Please note that these numbers are for pure water. If the water contains other chemicals, suspended particles, algae, and other things as our water does, its DO capacity is lowered. This means salt water holds less O2, so you may not want to run high salt levels in Summer.

Given that our fish need good DO levels, what happens when the DO level drops lower and lower. According to the water quality criteria for the Commonwealth of Kentucky, DO levels of 5.0 mg/L and lower cause extreme stress to all aerobic life. This includes not only the fish, but other organisms in the pond such as aerobic bacteria. As it is these bacteria that make your bio-filter work, lower DO levels can damage your filter. At 1-2 mg/L larger fish will die in a few hours.

Many of us have horror stories about losing fish from anoxia. Mine goes like this. When Sandee and were fish vendors we had 30 koi of 8 to 12 inches that had survived three or four cullings and were ready for the fall show. We had them in an 800 gal. pond with an adequate pump and filter. However the surface of the pond was covered with hyacinths. One night the hose slipped of the pump. Between the lack of moving water and the plants sucking all the O2 out over night, we lost 20 of the 30 fish by the next morning. Only the smallest fish survived.

Now you know what damage low DO can cause, it is important to be able to recognize it in your own pond. The tell tale signs are:

1) Fish will be swimming near the surface, gulping air.

2) Large fish will be in greater distress than smaller ones.

3) These behaviors are more pronounced in the morning.

4) The water may turn dark in color; gray to black or brown as algae die.

5) As the pond dies, it may give off a foul smell.

6) Remember this can happen in a matter of hours.

So how do you react to this emergency?

1) The first thing to do is get the water moving however you can. Air pump driven air stones, set up a water pump so it will"fountain" or spray water about the pond,

2) If your water volume is small you may want to change some of it, provided you can replace it with good oxygenated make-up water. This will also help lower the water temperature and increase its O2 saturation level. Please remember that water from a hose or from a well has very low DO and if not handled property will exacerbate your problem.

3) Introduce hydrogen peroxide 3% USP (standard drugstore type) @ 1C per 100 gal. as a maximum dose. Start with 1C per 500 gal. at first.

4) Remove as much debris, old food and mulm as you can, this includes dead fish.

5) Clean your filter to make sure it is free from organic matter and allowing maximum water flow. Make sure the water return is as agitated as it can be.

Telling you what to do when you are in an emergency is fine, but it is better to tell you how to stay out of a low DO condition altogether.

1) Make sure you agitate your water as much as you can.

a) Have a water fall.

B) Run an axillary air pump and air stones: Air stones work by causing a surface disruption at the air-water boundary. They do not aerate the water by themselves.

2) Keep plants, but keep them to a minimum. Floating plants such as hyacinths should not cover more than one third of the surface at any time. Run anacharis and other plants considered oxygenators, but keep them under control. Remember they take out O2 at night.

3) Keep your filter clean and free running.

4) Make sure your pump pickup is at the far end of your pond from where the water returns. This assures good water flow throughout the pond. Your pickup should be a bottom drain or from a sump at the lowest part of your pond.

5) Cover your pond to keep the water cooler in summer.

6) Always spray makeup water into the pond.

7) Get a UV filter to keep the greenwater down

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