Category Archives: Koi & Pond Fish

Trip to Blue Ridge Fish Hatchery @ Zokomo

I went to Blue Ridge Fish Hatchery this spring to give a seminar for the folks at Garden State Koi –  it was a LOT of fun. I put the notes on here somewhere. 

There was a guy there named Andrew Hedman and he shot a bunch of video and pieced it together into a tour of Blue Ridge Fish Hatchery and it’s a good video. Pretty much captures the meat-and-potatoes of that visit.  Continue reading Trip to Blue Ridge Fish Hatchery @ Zokomo

Bigger Batch Issues w/ Medicated Food

Making a big batch is a little bit more difficult because mixing the confectioners glaze/medicine mix have to be done evenly so it really kind of takes two people. One person to drizzle and one person to stir.

*Note: this document is intended to convey “how I do it“ and has nothing to do with recommendations, prescriptions, or instructions to you. If you think so, you are mistaken.

This batch called for roughly 700 mg of medicine per pound of food based on a 3% feeding rate and I put in 1500 total. It’s 2 pounds of food. If I had it to do over again, I would have made this with 2000 mg to account for some of the loss of medication during the crushing process. Continue reading Bigger Batch Issues w/ Medicated Food

Koi and Goldfish and KHV Cross Contamination

Dr Johnson,

I got your address from my friend Jason who you recently helped with a pecan nut problem.

I may or may not have a KHV problem. If I can give you the story I hope you can tell me if there is anything I should do.

I dug a pond last fall and have 2, 5 inch koi doing fine in it. I have 5, 4 inch koi inside doing very well.

I have a lotus in a whiskey barrel that I’ve had for sometime and put cheap goldfish in for mosquitoes. They usually die quickly and I never thought much about it until I started reading about KHV and saw pics of Koi with KHV. I remember one of the gold fish having a dark patch on its gill cover that looked like a post mortem shot of a koi with KHV.

I have wintered umbrella palms in the lotus barrel.

So my questions.

1. Should I be concerned

2. Is there a nucleic acid test that can test water

3. Is there a non-invasive nucleic acid test for fish

4. At what point should I bring the outdoor fish to you before I move the indoor fish out.

5. Should I throw out the plants or is it safe to put them in the pond

If there are any products I need to purchase from you, please let me know.

Thank you

My Answer:

Koi Herpes Virus is not a legitimate liability to goldfish owners.
Testing is a mixed bag – – because if you test and it’s positive, you have to (by law) go on record with the Federal Government. It’s a “legally reportable” disease so the testing agency has to ‘tell on you’ and that COULD POTENTIALLY mean that you have to surrender your fish to the Fed and the pond gets drained and closed.

Any Koi that carries KHV in cold water will “break” with it when it’s warmed to 70-78 DF
Any Koi that is infected with KHV will ‘get over it’ when it’s warmed to 84 DF.
They’re not considered ”cured”. By anyone but me, and also everyone in Israel.

The plants (left without fish for a week or two) will bring no diseases with them to a receiving facility. I can say that with even more certainty if the plants are in the seventies DF when you quarantine them.

So if you think the Koi outdoors are harboring KHV all you have to do is bring one up to 75 degrees and give it a week to break.

And if it doesn’t, you’re golden, on the KHV issue.

Besides a few recommendations on about heaters and air pumps, I don’t officially “sell” anything so you’re good there 🙂


Inherited a Koi Pond III

Inherited a Koi Pond III

We are not going to talk about viruses at this point, you just inherited a pond you have plenty to worry about. But you should know that there is a virus that can kill all of your fish in under a week if you don’t prevent it with quarantine.

It’s called Koi Herpesvirus and there is a lot of information about it.

Just to plant a bug in your ear with regards to Koi herpes virus, you can break its cycle and save your fish with simple heat. Carefully done, take the fish to 83 to 85°F, and the disease process will stop. Fish that are not “too far gone“ will live. They are considered contagious after surviving Koi Herpes Virus however there are many elements of this that are not supported in work done in Israel on carp.

I can summarize the Koi KHV x Heat equation by telling you:

Koi heating 101
A couple paint bucket warmers carefully suspended above the water line and operated on a thermostat….

One of the first times that that deadly virus, Koi Herpesvirus, was seen in the United States was when infected fish were sold to buyers all over the country at a Koi Show. The fish were distributed to individuals ponds from New York to California and as far south as Arizona, New Mexico and Texas. Shortly after those fish were sold and taken home from the event where they were sold, outbreaks of Koi Herpesvirus erupted everywhere the water was under 83°.
Yes, you heard me right.

Owners that bought the fish from that infected show, took their fish home to Arizona New Mexico, Texas, even parts of Florida, and experienced no illlness nor mortalities and I presume their fish are still out there today doing fantastically. Nobody thought to go through and test those fish, I guess they felt lucky, or the virus had somehow ‘overlooked’ the fish that went into the desert.
The collections in more temperate waters died.

What If My Koi Get Sick Without Getting New Fish?

If your fish gets sick, and it doesn’t seem to have anything to do with a new fish, you have to look at water quality. You have to understand what the nitrogen cycle is, how your filter is working, and how it is maintained, you need to notice if you have too many fish, that means: “more than 1 inch of fish per 10 gallons of water“

I put together a short course of 20 items to knock down if your fish get sick. Nobody ever gets to the end of it because typically they have figured out what’s wrong by the fifth video.

As a brand new pond inheritor or owner, if you have any questions please reach out!

So You Inherited a Koi Pond!?

So you inherited a Koi pond?

Maybe somebody died, (sorry), or maybe you bought a house that has a fishpond. Maybe you’ve always wanted one and the presence of the fish pond has been a pleasure. But there are fish in there, and you’re wondering what to do about them?
What I think I will do, is go through the most important things for you to know right up front.

First and foremost, fish can only live in water, or ponds (like you have inherited) as long as there is some water circulation. This is more true if there are more fish, and this is even more true if the water is warm. You see, water carries more oxygen when it’s colder. So if you’ve inherited your pond full of fish in the winter time then circulation isn’t really that important (besides, perhaps, keeping ice from forming over the entire surface of the pond). To learn more about the care of Koi during the frigid months of winter and about ice in the pond, please search the site for “winterizing“. (There are three articles)

So, if you have fish living in the yard somewhere, you must always be vigilant to make sure that there is sufficient circulation to provide them with enough oxygen to live. It is not uncommon for a person with a sizable collection of Koi or pond fish to lose them all in the middle of the summer when the water is warm, due to a power outage and a lack of water circulation.

Okay, before we go much further I should let you know that there are things called Koi clubs and “Pond Clubs” that are groups of people who are crazy about Fish and Ponds and if you don’t want the fish that you’ve just inherited, and you can reach out to these clubs, very commonly, they will find homes for the fish.
And, why would you necessarily want to fill the pond in and get rid of it when you could just get rid of the fish that seem to represent work and concern?

The answer commonly seems to be “I don’t want mosquitoes in my yard”

Mosquitofish control mosquitoes in a koi pond
Gambusia affinis, what they lack in “pretty” they make up in “tough” and “skeeter-eaters”

Well, on the one hand, you are absolutely right. A fish pond or standing body of water with no fish in it to eat the mosquito babies will become a breeding ground for mosquitoes. However, you don’t have to have Pond Fish to keep the mosquitoes at bay. In fact, there are fish called mosquito fish, or Gambusia, or even wild guppies that you can put in there which require no filtration or any particular care, and they become very abundant.

You can also put a handful of “feeder Goldfish” from the pet store into this pond, they are small fish about $.16 each. They are never particularly healthy but that’s not the point. You would put a dozen of them into the pond and they will either die back to the carrying capacity of the pond, or they will reproduce to the carrying capacity over the pond. If it’s a good pond, you may have unlimited little goldfish in two years.

No koi in a pondless waterfall.
Atlantis Watergardens made this miracle. They have a Youtube channel worth a look.

You’re not even obligated necessarily to keep the Pond! There’s a technique where the pond is filled in with gravel and rocks and sand and driftwood and then the waterfall looks like it is just draining into a swale. They are called Pondless waterfalls and many pond set ups can be modified into that, so that you’re not even dealing with standing water. Nobody drowns in a pondless waterfall. The reservoir is under the gravel and dirt out of sight. Keyword search pond list waterfalls and you will be loaded down with information on this relatively new phenomenon.
Having read this far, you know you can get rid of the fish anytime you want, you can keep the pond and keep mosquitoes at bay, and you can even fill the pond in mostly and have a pond less waterfall, but if you are still reading then it is probable that you would like to keep the fish and enjoy them.

You already know that the water needs to be moving around (preferably a lot) in warm weather, to keep the fish alive.

What then?

Well the fish have to eat. Pond fish are not demanding. You can get a decent staple food for less than two dollars a pound.

How to Feed Koi:

You should stand next to the pond and scatter food on the surface and wait till it’s all gone before you put any more in, then put a little more on the surface, and do that for a total of five minutes. Take note of how much food they ate over the course of five minutes without leaving any on the surface. That is how much you should throw into the pond tomorrow. While it is fine to feed fish several times a day, I would recommend that, at first, you feed them a little less than you’d like and you only feed them once a day.

Without a doubt, water pollution is the number one killer of pond fish especially among beginners.

Ultimately, it is important to understand what “pollution“ actually is because there is a certain amount of chemistry involved in that, which you have total control over, and if your fish are worth any money or sentiment at all, you should master it. I would say it is easier than mastering a thermometer. If you look up “Water quality“ you will be loaded down with information about things like ammonia, nitrate, pH, and oxygen as well as carbon dioxide and live plants.

All of those things fit together to create your “water quality“ but for now, let’s just under feed our fish, and rarely.

Clean, Clear Water

If the water is nice and clean, then it suggests that the pond is “established” and has beneficial germs and a certain “equilibrium” to it. It may also be getting lots of new water through an overflow water input system. Advanced hobbyists do this. Or, it might just be understocked, not many fish taxing the environment.
But in many cases you have inherited a pond that looks pretty good because it has a filter on it.


Constant Salt In The Pond: Please Don’t.

I was browsing for a salt document and I found a web site with someone who should know better, recommending that people salt their ponds all the time, to maintain a moderate 0.1% solution of salt all the time.

Not a good idea.

Fish and plants don’t ‘thrive’ that way. Your fish could be doing “okay” with salt all-the-time, but they’d be doing better and more vigorously without it. Besides, parasites get used to it.

Vitamins For Freshwater Fish Are a Waste of Money

Vitamins in teleost freshwater fishes are another way to spend money. But before you buy vitamins for freshwater fish, please put the money in an envelop and mail it to the Department of Labor. It will do you about as much good there as it will in your fish tank.

Freshwater fish are inundated by water through their skin and gill. Indeed, if they never took a single sip of water, they would always be over-hydrated. And so they are. Their kidney is engineered to excrete colossal amounts of water all the time, while recovering precious electrolytes and solutes. The freshwater fish never does take a sip.

So how do the vitamins get into the fish?

“Indeed, they are absorbed!” reply the marketing weasels.

“But nay” say I, “The fat soluble vitamins cannot passively cross the gill membrane nor the skin.”

“So perhaps the water soluble ones can!” Exclaim the marketing weasels.

“But they don’t!” I say, “Because as soon as an organic water soluble vitamin encounters another organic molecule of almost any type it becomes bound out of solution, not to mention that most of these vitamins are already so unstable they must be kept in brown glass bottles. How long do they actually last in the water, so that they might be absorbed by the fish?” I query.

“Less than five minutes.” Comes the sheepish reply.

“Perhaps we could recommend that the vitamin-fortified liquid we have put so much ‘R&D’ into could be applied to dry food and fed.” Suggested the other weasel, nodding hopefully.

And so they did.

Phosphate Removers Are A Waste of Money

You should be aware that in the normal scheme of things, phosphates cause algae to flourish. As such, phosphates became ‘the enemy’ to marketing weasels who would have you believe that algae are the bane of our existence. Phosphates are not considered overtly harmful to fish in naturally occurring amounts. Phosphate removers will attempt to remove phosphates from the water, but you should know that the products are just an exhaustible resin.  Once they have accomplished their goal, and your water is blissfully free of phosphates, you will probably have poor-doing plants because plants tend to require Phosphates, Nitrate and iron to flourish. You will probably have higher than ideal Nitrate levels because they are not being used efficiently by plants. Worse; the fish will soon be fed, and then have a bowel movement, which completely replaces your preciously reduced phosphates. It’s a losing battle. When the phosphate removing resin is completely exhausted, you can replace it and start over again.

A Topical For Bacterial Sores or Ulcer Disease in Koi

A Topical For Bacterial Sores or Ulcer Disease in Koi

With bacterial sores, one of the key elements is killing ALL the germs in the area. removing as much dead tissue and grossness as possible in ONE PASS and leaving something disinfectant in the vicinity as long as the water will let it stay. That seems to require a “stain” like Mercurochrome or similar.

Except Mercurochrome is pretty much straight-up mercury and good luck getting that (You can, lol – just click here).

An old standby for me is Iodine. But you need an aggressive staining iodine and you need to be able to get it ON a wound while getting dead-stuff OFF the wound.

Enter, Tincture of Iodine, 7% – 10% very strong.

And WOVEN gauze sponges. (See below) Most of what you find these days are “non woven” because they are considerably softer and MORE ABSORBENT. Finding “woven” gauze is kind of hard these days.

Ulcer disease in Koi debridement wounds iodine
^ Where to buy: WOVEN gauze sponges.

But when you’re debriding a Koi or other fish wound, you don’t care about absorbent, you need a “gentle roughness” for scrubbing. Not scrubbing, more like, rubbing. Kind of rubbing, but mainly “removing” dead stuff and “stopping while you’re ahead”.

You get the idea from the above that it’s a “finesse” sort of “experience” thing.

A Topical For Bacterial Sores or Ulcer Disease in Koi

Tincture of Iodine is available in several strengths. I used to buy the two-percent solution off the shelf at the drug store, but I felt like I needed something stronger. So I inquired of my local pharmacist and he supplied me with a seven-percent solution, which is fabulous for wound cleaning. Care must be taken to avoid using it near the gill. It may run under the gill cover and damage gill tissue. Fish hate that. ‘Really.

Tincture of Iodine will stain you severely, but does not ‘hurt’ the skin. It could do serious eye damage and so I must recommend that you wear protective eyewear. If this compound gets on the cornea of the fish, it will be of no consequence, as the cornea of the fish seems able to withstand this compound easily.

Use of this and almost any other topical should be limited to a single use. Once the wound has stopped bleeding, seems less red, and the edges seem to be ‘organizing’ into a thick white rim, do NOT re-apply any topical. You will disrupt the necessary migration of epithelial cells across the wound. This is the only way that large sores will heal. If you’re doing daily scrubs on the wounds, they cannot heal. A vicious cycle is propagated.

Salt Dosing Journal for Ich or White Spot – A Case

Salt is the greatest bath treatment of all time. This would have to be one of the single, uncontested assertions made in this website. Salt is both tonic to fish and toxic to parasite. It’s got a wide spectrum encompassing most of the ciliated protozoans and it can offset the negative effects of some water quality derangements such as Nitrite accumulation.

Salt can occur in numerous forms. The first salt I ever used was from the pet shop and cost quite a bit. It worked very well. It must have been very special. Perhaps distilled from the tears of Hawaiian orphans.

Many folks have used Kosher Salt, Water Softener salts, “Solar” salt, rock salt, Sea Salt, Ice Cream Salt, Synthetic Reef Salt (Instant Ocean®) Non-mineralized Salt blocks for cows, and table salt. Results with all of these have been excellent with the following notes: Sea Salt is rich in carbonates and will raise Total Alkalinity and pH which may be undesirable if there is a significant Ammonia accumulation or your fish are adapted to an acidic pH. Cow Salt Blocks occur in a mineralized format, rich in Magnesium and other minerals. You’ll kill your fish unless the salt lick is 99.9% pure salt without trace minerals. Make sure the label indicates the salt is not trace mineralized and that the salt is 99.97% NaCl.

No salt should contain Yellow Prussiate of Soda, or YPS. Another anti-caking agent contains cyanuric acid. Avoid this as well. The salt should contain no Iodine because while this will have no negative effect on the fish, it may damage beneficial bacteria.

Why is Iodine bad? Well, a hundred years ago when I first started using salt, I’d add it “all at once” and that caused osmotic ‘shock’ to the nitrifying bacteria and we’d see a pulse in nitrogen. I assumed it was the Iodine. That’s what I published. That misinformation’s hanging around to this day. My bad. Sorry.

Why is Yellow Prussiate of Soda “Bad?” Well, I didn’t know where that got started. I just read that. And a LOT of the time, the YPS didn’t matter so I started to think, “Ehhh who cares?”   but then something happened up in Tennessee that made me consult a chemist. A mess of fish got sicker and sicker with YPS salt being used. Why?

It turns out that YPS (Yellow Prussiate of Soda) turns into “Prussic Acid” in water. And normally that gets neutralized by carbonates in the water. But if there aren’t enough carbonates, the pH becomes acidic and can hurt the fish. So what I learned was: In hard water, YPS Salt is fine. In soft, low carbonate rich water, YPS can burn the fish. Or crash the pH.

On the other hand, the desiccant Sodium Alumino-silicate is just fine.

Salt for use against ick or ich white spot
Salt for use against ick or ich white spot

Salt Dosing Journal for Ich or White Spot

Indications for the use of salt include the elimination of parasitisms caused by vulnerable ciliated protozoan parasites, curbing the absorption of Nitrite, and reducing the osmotic pressure exerted by fresh water on any hole in the skin or gill.

Salt also makes popcorn taste great, and it melts the snow on your driveway in winter.

Dosing salt is usually simple.

The dose for 0.3% solutions is 1 tablespoon per gallon. This is the amount used for most protozoan parasitisms

The dose for 0.6% solutions is 2 tablespoons per gallon. This is the dose for salt resistant Trichodina and Costia. Dosing variations exist based on live plants, volume of the water, what parasite is targeted and what species of fish are involved.

The dose for 0.9% solutions (common in German texts) is 3 tablespoons per gallon.

First, you must remove any live plants of value from the aquarium.

  1. Perform a significant percentage water change before starting, because you will want to avoid water changes if possible after salting in order to maintain a stable concentration.
  2. At the zero hour” add one third of the total dose after pre-dissolving it in a small bucket of water.
  3. Wait twelve hours while the fish acclimate.
  4. Then apply the second ‘third’ of the salt dose, after pre-dissolving it.
  5. Twelve hours after that, you’ll apply the last ‘third’ of the total dose. The whole amount has been added over twenty four hours, and there will be nominal effect on the fish or filter.

Let’s work as example to keep folks out of trouble:

This fellow, whose name is Vino DePascagliatelli (he’s fictitious but the name is fun to say fast) has a fifty-five gallon fish tank full of fine Chinese Ranchu. (He never went for those big ugly-headed Orandas). Anyway, his fish break with Ich because he bought a new fish from an otherwise reputable dealer and did not quarantine it. The Ich is obvious because the fish have white spots all over their fins and bodies. So he checks out this book and quickly figures up his total dose of salt.

0.3% represents one tablespoon per gallon.

He has a fifty-five gallon tank and the fish are stable, so he figures the dose into “thirds” for gradual addition. That would be 18.3 tablespoons every twelve hours.

It’s ten o’clock by the time he gets home with the salt. He bought So-Lo® brand rock salt with Yellow Prussiate of Soda. He’s just about to burn his fish when his wife notices it: “Vino, Vino!! Oh my Gawd, Vino lookit he-ah! Lookie! Doc Johnsin’s book says not ta’ use no salt wit Yella’ Prussiate uh Soda in it!”

Vino grabs his receipt and runs down to the local mart, and exchanges the salt for Dandy® brand, which has Sodium Alumino-silicate as its anti-caking agent. This is fine.

He gets home just in time to meet his wife at the door. She’s going to get lunch with her friend Maria, and she still has curlers still in her hair.

He checks his watch. It’s noon. Vino adds 18 tablespoons of salt. When it dissolves it leaves a little sand on the glass bottom of his tank. No big deal.

“Docta Johnson din’t say nuttin’ ’bout no sand bein’ left behind in da tank”. He’s a little miffed but he ignores it, as he should.

Twelve hours later, at midnight, his wife wakes him up.

“Dincha’ hafta add some mowa salt ta ‘dat fish tank ovah daya?”

“Jeez Stella, ‘tanks fer wakin’ me up, I almast fa-got!” Vino rubs his eyes and applies another 18 tablespoons of salt to the tank. He goes back to bed. Stella still has the curlers in her hair.

It’s noon the next day when Vino walks over to the tank. (Well, Vino kind of struts like a large chicken, and he has a gigantic pompadour, but that’s another story). He leans down and notices the fish are perkier. The spots are still there, but he’s a trusting fellow. So he adds his last eighteen tablespoons and sits down to read the paper.

That night, Stella is counting all the white spots.

“One thousand eight hunnid and ninety seven! Vino! They’re goin’ away! Yestaday dare wuz two ‘tousand five hunnid and toidy!”

Vino puts his head in his hands. She starts counting the white spots all over again.

Forty eight hours later, she is counting the white spots again. She still has curlers in her hair.

“Jeez, Stella, are we gonna go to some kinda big Poddy at da end ah da munt? Whatcha wearin’ ‘dem ‘coilas fa?”

“Oh shut up, Vino!” she retorts. “I shou’nt tell ya dis, ’cause yer bein’ such a goombah, but, doze Ick bugs is all gone away!”

Vino jumps up and looks. Within about 72 hours after the last salt dose, at seventy-four degrees oF all of the Ich cysts have vanished from the skin. He leaves the salt in for ten more days just to be on the safe side. Later that week he wins the New York Lotto and sends Dr. Johnson a new Lincoln Town Car for all his careful advice in this great book.

If the fish are dying off quickly, it is advisable to add the salt dose all at once. This may have a negative impact on filter bacteria but may be life saving in the case of Chilodonella, Costia or even Ich in smaller fishes.

Is it possible to apply too much salt?

Well, it would be hard to do since Koi, goldfish and pond fish can handle high salinity. They will survive salt levels up to 0.9% and higher. However, this should be recognized as a stressful salt level and only used when absolutely necessary. Small, weak fish would do their best at 0.3% with observation. “Not Worse” is a good result. If the fish are ‘hanging in there’ after a day or two, then you can climb to 0.6% without losses.

This is a Koi, goldfish and pond fish health book but many people keep tropical fish with their Koi, goldfish and pond fish. Several species of catfish are negatively affected by salt. Er, well, that means they may stop breathing, severe stiffness results and they are not as entertaining to watch anymore. Examples of these fish would be wild caught Brokis britskii catfish, some wild caught Corydoras species, Rafael cats, Ramirez cichlids, and Rasboras. There are other sensitive tropical barbs, so any fish you are not sure of should be removed before treatment.

Salt Dosing Journal for Ich or White Spot