How To Treat Fish Diseases Without Testing or Learning Anything At All

How to save your fish almost every time, by adding stuff to the water.

The most common approach to fish diseases, is just to put medicine in the water with the fish.

I have spent over 20 years trying to get people to be better at the hobby and learn what they are doing, and to prevent future disease outbreaks, what they are doing wrong.

That educational objective has been an absolute fail. To this day, most people just want to put the medicine in the water.

“Come on. What do I treat the fish with?”

And so in this protocol, all you do is “add stuff”:

  1. New water,
  2. heat,
  3. pH buffer,
  4. salt, and
  5. APIs General Cure.

That is literally “it”.

And while I will spare you as much learning reading and testing as possible, I do need to provide you with more details on specifically how to add the above “stuff”.

Here is how to save most fish, without getting better at the hobby at all. At the conclusion of this tutorial, you will have salvaged live, healthy fish. (Until they leave the hospital tank and go back into the main facility where the original problems remain unrecognized.)

The following protocol does not apply to Marine Fish. It does not apply to very large fish that would be inappropriately housed in a 10 gallon facility. Although, the protocol can be scaled upward to any size facility you need.

Step one, obtain a 10 gallon or larger container that can be heated, and covered.

For best results, ensure that the hospital facility is at least 1 gallon of water per 1 inch of fish.

Without understanding why, if it turns out your hospital facility is larger than your main facility, then you have just accidentally learned that your fish are overcrowded and that may be all that’s wrong with them.

Fill the container within 2 inches of the top with tapwater.

Apply de-chlorinator. (Buy)

Install a sponge filter powered by an air pump, and a small heater (100W per 10 gallons) to achieve a temperature of 78° in your hospital facility. The sponge filter (specifically) is much more important, and much more of a boon to this protocol than you should bother to learn. Just do it.

Okay okay okay….here’s a fact but I said I’d just show you how to put stuff in the water….  A sponge filter with <25ppi makes life hard for swarming parasites. Really hard. It can hold them long enough for them to die without a host. It’s not a ‘treatment’ but it IS an impediment of consequence to ciliate and other ‘swimming’ microscopic parasites.

Buy a spray of silk plants to put into the hospital facility to provide the fish with much-needed cover (a “hide”) to minimize the impact of stress and crowding.

Bio seed your hospital facility from your existing facility. Bioseeding is the transfer of bio-active-organics and beneficial bacteria from your existing, donor filtration system to the new, sponge filtration system. Sponge filters lend themselves especially well to this technology. Not hang-ons or canisters.

In the hospital facility, you will need to regulate pH to a species-appropriate level, so without learning about pH, this is how you do that:

Goldfish, and just about all the ‘bread and butter’ species in franchise pet stores are acclimated to Neutral.
South American tetras, cichlids, barbs, South American discus, catfish, Oscars, and most other South American fish will need a ph of 6.8 to neutral pH so you could use neutral regulator 7.0

African cichlids, mollies, guppies, brackish water fish, gobies, monos, scats, most live bearers, and many other African species appreciate a slightly higher pH and you would use “African Cichlid buffer”. Follow label directions.

For the most part, you will have addressed a pH problem without understanding it. Sadly, this will not prepare you to manage pH in the main system when the fish go back in. That would be a departure from ‘just adding medicine to the water’ which is the stated goal here..

Having done all of the above, you have created a suitable hospital facility of at least 1 gallon of water per 1 inch of fish, with an appropriate pH for the species, with some foliage-cover for the fish, well-aerated by, and filtering it with, a sponge filter, that has been cycled from the existing system, the water is dechlorinated, and heated to 78°. You have a hospital facility that is suitable for 97% of all weak or sick fish.

Feed freeze dried krill in sparing amounts, 2x daily which has been crunched down to a size that is appropriate for the fish you have in the facility.

Now you know how to make a suitable hospital facility without a shred of understanding as to why it all functions together to save fish so well.

Time to move fish:

Check the water temperature in the existing system, and check the water temperature in your hospital facility to make sure that they are within 5° of each other. That is, 5° FAHRENHEIT not Celsius.

It may be that the main system is far too cold, which was the problem in the first place but we didn’t want to test anything, we just wanted to add things to the water. So you may have just accidentally learned that the water in your main system is too cold.

Move affected fish from the mother system to the hospital facility.

The best way to accomplish that would be to net the fish into a bowl or cup, and move them over and slowly dip hospital water into the cup mixing gradually with the mother water and then after a minute or three, letting the fish go into the hospital system.

Watch the first fish you transfer for 15 minutes to make sure that there is no shock. If all goes well with the first fish, you may move the remainder into the hospital tank.

There is a 80% chance that the fish will immediately improve in the hospital tank because the pH is not crashed down to 6.0 …like it is in the main system, meaning that a crashed pH was the problem the whole time in the main system. Recall that the goal was not to test anything, but to just add things.

While the fish are in the proper pH in the spacious hospital system, there is a good chance they will just get stronger and stronger until you move it back to the main system with the crashed pH. Gosh if only we were willing to actually test the pH.

I would prefer that you leave no fish in the main system as they may harbor parasites-in-waiting, for the fish when they come back from the hospital system. If you leave fish in the main system, you will not have corrected their pH issues either, old-water quality issues, trematodes, or potentiated their recovery from bacterial infections.
In other words, while you will have blindly improved literally *everything* for the fish that go into the hospital tank, you will have corrected nothing for the remaining fish in the main system.

And, not understanding the impact and value of a proper pH, new water, high aeration and sponge filtration, bioseeding, and the effect of temperature on the immune system, the fish in the main system will not be receiving *any* benefit.

In a spacious hospital facility, under high aeration with sponge filtration recently bio seeded, dechlorinated water with the proper pH, plant material for cover, no stress, at 78°, the fish are ready for treatment.

That is simply salt at 0.3% and APIs General Cure which is Praziquantel and metronidazole.

What these two compounds treat is unimportant. We just want to add things. This combination of therapies addresses a multitude of pathogens from ciliates, to trematodes, to cestodes to hexamita, and will exert a complete control of 90+ percent of pathogenic issues without endangering the fish.

Please follow instructions in the salt article on my website at The nuts and bolts of that regimen involve the addition of a total dose of 3 teaspoons of non-iodized salt per one-gallon of water, spread over the course of 36 hours to systems containing no live plants nor any wild caught South American catfish.

Follow label instructions on the API General Cure. For the purposes of this ‘just add stuff’ treatment and sparing you the science behind the interval, that would be an application every other day for only three treatments.

Fish diseases Cured without learning

You can save most fish without learning anything by warming them to 78° and applying new water, salt and general care.

Without the slightest notion as to why the fish are recovering, they will strengthen.

Feed them per their species requirements, or feed freeze dried krill which is eagerly excepted and highly nutritious, keep them in the hospital facility at 78° with a properly buffered pH and a highly functioning air-driven sponge filtration system, under the elixir of salt and General Cure, until they are strong and then move them back into the main facility.

If parasites were suspected in the main system, they have to die.

You have two options. You can treat the main system with the salt and General Cure, or you can leave the main system fish free for two weeks at 78df – meaning you have deprived of parasites of their host and thereby extincted them.

But either way you should keep the fish in the hospital system with the salt for two weeks to make sure all their parasites have expired.

On return to their main facility, which is conceivably smaller than the hospital facility (please keep tropical aquarium fish at less than 1 inch of fish per 1 gallon of water), they may be too cold (please keep aquarium fish at 78 DF), the pH may be too low (please buffer pH to neutral), parasites may still exist, they may have too-little foliage cover, high levels of background pollution may exist without adequate filtration (Please use sponge filters), water changes (please replace water frequently) or aeration, making illness an inevitable recurrence.
But the hospital facility will always be there, bubbling along at neutral pH, with superior filtration and oxygenation, and at 78df as an appropriate environment to recover the fish if they fail again.

Materials list:

10 gallon or larger aquarium or fish-safe container.
Thermometer x 2.
Air pump.
Sponge filter.
Plastic or silk plants.
Species specific PH buffer or Neutral 7.0.
API General Cure.
Non iodized table salt.
Fish net.
Freeze dried Krill.
Plastic cup.
Aquarium heater 100W per 10 gallons.

I cannot help but mention here that anyone keeping fish as pets should, whenever possible, employ a trickle water replacement system. Your “luck” with pet fish will be immeasurably improved. The fish will seem “bullet proof.“

Treating Fish Diseases Without Testing Or Training

How to Treat a Sick Betta

How to Treat a Sick Betta

This simple protocol intercepts most of the common problems affecting bettas. I go through the common causes of Betta sickness and we fix them, one by one. By the end of the video you will understand the basics of their environment where most people drop-the-ball, and a gentle treatment for most of their ‘bugs‘.

Treating A Sick Betta: Symptoms of Disease

Treating A Sick Betta: Symptoms of Disease

Treating A Sick Betta: Symptoms of Disease

Treating Finrot and Mouthrot In Bettas

Treating Finrot and Mouthrot In Bettas

Finrot and mouthrot are bacterial or fungal infections that occur to Bettas or Siamese Fighting Fish when they’re worn down by chilling, poor water quality and, or parasites.

By themselves without parasites, in good warm water, Bettas don’t get finrot or mouthrot. (Although you can BUY stressed fish that soon break with it.)

Treating Finrot and Mouthrot In Bettas

Treating Finrot and Mouthrot In Bettas

So, what to know when Treating Finrot and Mouthrot In Bettas?

This video protocol steps you through Treating Finrot and Mouthrot In Bettas with specifics and it’s successful.

HSUS Humane Society of the United States – Not “THE” Humane Society. Wow!

HSUS Human Society of the United States


I didn’t know that the HSUS wasn’t associated with “The Humane Society” down the street from your house. And only gives 1% of it’s revenues to shelters! And there’s compelling evidence, including the words that come DIRECTLY out of the mouths of the leadership that prove that HSUS is not as much animal WELFARE as it is animal RIGHTS and folks who like hunting, fishing and meat should be highly alarmed. This is a well funded organization without the actual expense of taking care of legit animals-in-need.

“It takes tens of millions of dollars to run campaigns against so many domestic targets, and HSUS consistently misleads Americans with its fundraising efforts by hinting that it’s a “humane society” in the more conventional sense of the term. Buried deep within HSUS’s website is a disclaimer noting that the group “is not affiliated with, nor is it a parent organization for, local humane societies, animal shelters, or animal care and control agencies. These are independent organizations … HSUS does not operate or have direct control over any animal shelter.”

HSUS Human Society of the United States

HSUS Human Society of the United States

From :

“HSUS is big, rich, and powerful. While most local animal shelters are under-funded and unsung, HSUS has accumulated $195 million in assets and built a recognizable brand by capitalizing on the confusion its very name provokes. This misdirection results in an irony of which most animal lovers are unaware: HSUS raises enough money to finance animal shelters in every single state, with money to spare, yet it doesn’t operate a single one anywhere.”

HSUS Human Society of the United States

Following this link to I will upload all the documents that support this discovery.

Humane Society of the United States


HSUS Dogged By Calls for Short IRS Leash – HumaneWatch

HSUS Plays Chicken with Whole Foods – HumaneWatch

HSUS_Charitywatch_Report Card_ D – HumaneWatch

Unpacking the HSUS Gravy Train (2011 Edition) – HumaneWatch

ASPCA American Society for the Prevention of Cruelty to Animals = Doesn’t Even Shelter Dogs


Note: I only care because I didn’t know the following stuff. I’m not on some ‘crusade’ because ASPCA keeps getting the funds that your LOCAL SPCA should be getting. It just made me mad that I’m looking at these pictures of boney dogs, and the request for a monthly $25 and it’s NOT feeding dogs! It’s low cost spay and neuter and taking harmed dogs from bad owners!

I had no idea that the ASPCA had nothing to do with my local SPCA! From what I can read in their annual report, they’re mostly spay and neuter in two locations (benefiting less than a few counties nationwide) and then countereducation on animal advocacy. Yay! I saw no information about them actually feeding a scrawny dog. I might not have looked closely enough but you can see for your self.

Aspca AdAmerican Society for the Prevention of Cruelty to Animals ASPCA

ASPCA Audited Financials 2018 < This makes them look their best. It’s written by them. I don’t have a stake in this. I was just amazed by what Charitywatch and

Let me give you the downloads before I send you off to for the rest.

  1. ASPCA Audited Financials 2018
  2. ASPCA Audited Financials 2017
  3. And if the page dies, it’s downloadable here:
  4. ASPCA Assessment by

Which Charities are the Best? Check with These Three:


My video on this subject. (Click)

American Society for the Prevention of Cruelty to Animals ASPCA

American Society for the Prevention of Cruelty to Animals ASPCA

American Society for the Prevention of Cruelty to Animals ASPCA

Link to website:

American Society for the Prevention of Cruelty to Animals (ASPCA)

Figuring out your Koi and Fish Health Illness Problem In Twenty Easy Steps

Figuring out your Koi and Fish Health Illness Problem In Twenty Easy Steps

What Is In Each Video? Table of Contents: Twenty Koi Health Video Tutorial

  1. Handling Stress -Have the fish been handled recently? Why that matters.
  2. Winter Stress -Temperature. Is it winter? Summer? Why that matters
  3. Feeding or Underfeeding – Feeding and Underfeeding. Why that matters.
  4. Ammonia Toxicity -Ammonia and it’s super common, why it matters and what it looks like.
  5. Nitrite Poisoning -Nitrites and what THAT looks like, why it matters and what to do about it.
  6. Nitrate Poisoning  –NitrAtes –  especially common fish killer / weakener in established pond.
  7. pH Explained -pH is the most common deadly water quality parameter to check. Crash discussed.
  8. Oxygen Levels – Oxygen levels. Why it might sag, impact of heat and plants, what to do about it.
  9. CrowdingCrowding. How many is too many. What does that do to fish?
  10. Still and StaleWater movement and turnover. Common. Stale, still water. Fish weakener.
  11. MetabolismTemperature; it’s influence, it’s pitfalls, the ideals for fish recovery
  12. InjuriesCuts and bruises. Is that an ulcer, or a gash? How can you tell. When and if you treat.
  13. Cleanliness Cleanliness – Is the pond clean? Properly maintained? Can fish recover in unclean ponds?
  14. Germs & MicrobesBacterial infections – a usually unnecessary video because 90% of people have figured out the source of a disease is in their water quality and husbandry. Injections, treatments, etc all discussed.
  15. FungusFungal infections, you’d be surprised the cause, and the treatment (or lack thereof)
  16. Bugs & CrittersThe Parasites, this is pretty common. What you need to know about them, and their treatment.
  17. Viruses like KHVViral diseases, like Koi Herpes virus and some of the skin-viruses that cause warts.
  18. Video 18 –> No video 18 lol
  19. QuarantineQuarantine. If you did it, then the list gets shorter. If you didn’t do it, (and how to do it) the field remains very wide.
  20. Further ResourcesResources for more help, diagnostics, fish vets who still do it.

If You Don’t Want to Know Anything But Just Add Things To Save Fish Look At This

What Is In Each Video? Table of Contents: Twenty Koi Health Video Tutorial

What Is In Each Video? Table of Contents: Twenty Video Tutorial

Doc Johnson’s December 2019 Newsletter


Hi Folks, Just a Few Quick Highlights.

I’m angry, that in order to have anything to say, vendors and organizations have to treat everything like an epidemic. I got a newsletter with the topic “Keeping Up With Pet Food Recalls” as if this was a “Big Thing” and we were in a hail storm of recalls and pet food disasters. So much hysteria.

In this “Issue” I am going to introduce you to a couple issues and if you’re interested you can jump over to the web site to learn more, but HERE ARE THE HIGHLIGHTS I THINK ARE REALLY IMPORTANT:

The Dilative Cardiomyopathy (DCM) from the food “thing” is real, but not really huge.

They’ve figured out that “grain free” diets based on Peas and Lentils are scouring Taurine from the digestive system of dogs. If you’re feeding a Peas and Lentils diet WITH grains, you’re okay. If you’re feeding grain free WITHOUT Peas and Lentils you’re good. But if you feed Peas and Lentils you need to have GRAIN (rice) or added Taurine to balance that out.  (Click To See What Has On This Issue)

Nevermind all that, Doc. I don’t have time for all that.

What do you feed Ajax? (Click here)

My Dog Is Itchy What Should I Do?

We’re having ridiculously good luck with Cytopoint injection. It’s safe and works great. If you’re using steroids or Apoquel, you really need to discover Cytopoint and ask your vet. It’s a vaccine against one of the enzymes that help create inflammation in the skin. Without that enzyme, redness and itching can’t occur. Case reviews presented.

I Found a Pump To Push My Whole Fish Room (And All The Tanks At Home, Too)

I did an illustrated review of a BIG quiet airpump I love more than my former, Gast regenerative Blower. So much quieter and so much more air output. The Aquascape Pro 60 blower.

Do You Want To Be More Findable, You Pond Installers? Koi Clubs?

In 2020 my web site will be blowing up with people needing help with sick fish and I can put you in front of those people for nothing. No charge. Nada. You can sign up and I’ll list you. No strings attached. Well, maybe a backlink. Here’s the FORM (Club Listing) (Installer Listing) (Link Exchange to Boost Your Website)

I Can’t Get Clout – What Replaces That Now?

Yeahhhhh they pulled Clout off the market.
So what now? Well, two protocols are good. 

For big parasites like Fish Lice and Anchor Worm I like the CyroPro and the one from Microbe lift.
Then to replace CLOUT –  I like:
A combination of API’s “General Cure” plus 0.3% Salt. (How That Combination Works)
Microbe Lift’s BSDT (Formalin Malachite) and there are several other effective brands. (How to Use BSDT Instead of Clout)

Everyone Needs to Know About Bio Seeding

So if you’re having a disease outbreak and you have to move fish to quarantine or you’re buying fish and need a fast quarantine, or your system is new and not “broken in” you can “borrow” beneficial germs from a donor system. Hopefully, a healthy on at equilibrium. There are some drawbacks discussed. I’ve even borrowed germs from my local pet shop. I am of the opinion that SOMETIMES, pet shop germs are better than no germs at all!  (Bioseeding Video)

If You’re Not Replacing Water Instead of Changing It – LISTEN UP

Trickle Systems are where it’s at. It’s running a dribble of water ALL THE TIME – and it makes fish bulletproof. I documented the whole thing from what it is, how to do it, the gear you need and even did the math on the Chlorine “thing” people worry about unnecessarily. There’s one article, that has a “See also” so be sure to look at the second one, too.
(Trickle Systems)

I don’t reach out much. But when I do I try and make it matter.

Look at this sponge filter. Click this link. You should find one of Amazon’s BEST typos. It’s a sponge filter for 250 gallon tanks. This sponge filter is the filter I’m using in ALL my tanks, even down to 30 gallons. They’re amazing. And they sell from $25 to $45 depending on how proud the vendor is. Then, THIS guy selling them for $9.99
Something’s wrong with that. So I ORDERED AND RECEIVED 15 of them. And, I continue to order 3 a week. It’s legit.

Thank you for your kind attention!

Doc Johnson 

If You Have Koi, You Need to Know These Ten Things

The Top Ten Things You Need To Know and Master For Success With a Koi Pond

The Super Basics of Koi

Figures out all the following:
Inventories quality, informational resources for a deeper understanding

But the most successful garden-variety hobbyist:
Feeds decent food, redundantly supplies their pond electrical, supports lively water movement and intercepts temperature impacts, knows their water’s quality via periodic basic water testing with strips, feeds sparingly and never gets new fish. Removes excess fish each year and avoids any drastic changes in population or water. If new fish are in the plan, quarantines new fish before deploying.

1. Crowding

You should have one inch of fish per ten gallons of pond water. You can have a bunch more koi than that IF the filtration and water quality will support them. To calculate pond volume figure out approximate length, width and depth in inches. Multiply them thusly:   Length inches x Width inches x Depth inches = Product    then divide the product by 231 and there you have US Gallons. If you have a mess of small fish, like goldfish and under 6″ you can have a lot more than an inch of fish per ten gallons. But the larger koi have more “mass” and oxygen requirements and put out more wastes and so they push the number down to one inch per ten gallons.


2. New Fish
The main source of parasites / germs is new koi. For the most part, “closed collections” don’t get parasites as a “new thing”. To avoid parasites and even some germ infections, quarantine is imperative which stymies the pathological “impulse buyer” but you know, live with your decisions.


3. Their water:

Water Movement is probably the most important thing in a pond. Most of the time when fish have poor body language, clamping and lethargic, it’s a lack of aeration and water movement in warm weather. How much water movement is needed?
Aeration is the single most important parameter with a close second being pH because of ‘crash’
Another area NOT to be ignorant of is water chemistry. Seriously. Flying blind is just ignorant unless your collection of koi is entirely expendable. MOST people have their koi and pond problems from chemistry, especially pH.

Chemicals like pH, and nitrogen.

Nitrogen is represented by Ammonia, Nitrite, and Nitrate. You should understand the basics of all of these. You’re not going to do “okay” for very long without understanding how Nitrate comes back to bite you in the butt. It’s the SINGLE MOST COMMON cause of chronic illness in the ponds of “know it all” pond and Koi keepers. They do a LOT correctly except they make VAST assumptions about their water quality because they think they can eyeball water quality.

Ammonia Discussed: When it happens, looks like, what to do.  (Video)

Nitrite Discussed: When it happens, looks like, what to do. 

Nitrate Discussed: When it happens, looks like, what to do. 

pH and pH crash are perhaps the most common water “quality” problem. Newbies won’t succeed long without a handle on this. Link to Video.

New Water

Water needs to be turned over and replaced with new water from time to time. At LEAST 10% per week. I run a constant slow water drip all the time. That’s because I’m lazy and don’t like to change water. Topping off the pond is not a water change unless the pond leaks. Evaporation CONCENTRATES chemistry. Doesn’t dilute it. When you replace water “fill and drain style” you need to apply a chemical “dechlorinator” to neutralize caustic chlorine that’s added to city water to disinfect it. If you’re using well water it’s not a “thing” but you might check the pH of the well water to know if it’s low.

Well water video

Dechlor video

Pond location and impact of temperature

If your pond is in the shade then it might get lots of leaves in it. And if it does, those leaves will decay and reduce the pH. If the water gets stained a “tea color” with leaf tannins (from leaves on and off the tree interestingly) the tea colored water will usually have a low pH, will slow healing of wounds in the Spring, and never grow algae. Tannins are anti-algae.

A pond in full sun  is prone to algae blooms, won’t have leaves in it, will not have much in the way of leaf-pH dynamic. But the water will be warmer and WARM WATER carries less oxygen so water movement and aeration are critical. If water movement fails in the hot pond in mid summer because, say, power outage, the Koi are gonna die.

4. Koi and Pond fish filtration:

So when you start out or you inherit a pond, the “filter” might sound simple but usually it’s not. They need maintenance of some kind. And they may or may not be “big enough” and an assessment is needed. I use ecosystem ponds with plants and gravel and a waterfall, happily. It takes MAJOR maintenance once yearly. I also run some systems on Bead Filters which pass the water through beads to clean it. VERY easy to clean, but frequently, and they can jam up suddenly, they die in the sun if the power goes out, and are a little expensive.

koi and pond fish do extremely well in eco system ponds.

In “ecosystem” ponds like Aquascape’s, the filter is actually PART of the pond and is invisible.

In any event, you should learn about filtration in earnest. For the beginner, an ecosystem installation or a bead filter would be your two best, scalable options. Cleanliness and maintenance of said filtration and water are paramount. Get educated by a knowledgeable installer or retailer of filters.

Ecosystem ponds

Excellent bead filtration I

Excellent bead filtration II

When filtration is needed or not 

Well if the pond is large and the fish load is quite small, you probably won’t need a filter. If there’s a lot of water movement and the water is clear and there’s not a bunch of cloudiness or particulate clouding, you might not need a filter. If the water tests okay with dip tests, you might not need a filter.

5. Their feeding

Overfeeding is super common. Just don’t. Koi do best when you have a ten year old feeding them and they forget to feed every fourth day or so. Underfeeding is better than overfeeding. If your koi are fat, something’s wrong and your water quality is probably paying a price. Fat koi are just fine. Feed twice a day, tops. Feed what they wanna eat in under ten minutes. Five minutes would be even better. Don’t feed near the skimmer or it’ll take the food and give it to the filter unnecessarily.

What to feed.  Feeding the right food is pretty important but really, in the scheme of things, it’s uncommon for a poor food choice to kill or sicken fish. Even catfish chow (while really inadequate) will just result in fatty livers and increased vulnerability to disease, not kill them.  Here’s where to learn all about Koi foods, and even some recommendations.

When Not to Feed and Why. So if your pond is large, natural and has ecosystem forage (plants, tadpoles, swimmy bugs, stuff like that, and the fish load is light, you might not need to feed. If the pond is a tech-pond without plants nor gravel you need to feed. There’s no natural forage.

6. Fish Body Language

Koi and pond fish body language is just an Early warning system for disease or poor water quality.

Here are some pointers:

  • If the fish are moving around, curious about food they’re probably okay
  • If the fish are NOT using their pectoral fins (the ones behind the head) they’re sick.
  • If the koi are wagging their bodies to swim, and not using fins at all, they’re about to die.
  • If the fish have clamped fins but then swim normally when you show up, something’s going on. Like a too high temperature or a sagging pH.

Survival is suggested by at least some willingness to eat, moving around.
Body wag is probably a goner.

7. Parasites

Where they come from? Parasites CAN “just happen” and they can be “carried” for a long time without causing disease until Winter reduces the fish’s immune system. Or, more commonly, parasites are not a “thing” until you buy some WITH PARASITES already on them. Quarantine fixes and prevents that. It’s easier to treat in quarantine and keeps your existing koi safe. VIDEO ON QUARANTINE

How’d you know they had them? Poor body language is an indicator something’s not right. Usually that’s a sagging pH and or a low dissolved oxygen. But if those two aren’t going on, maybe parasites are a “thing”. Fish will scratch on tank / pond surfaces and rocks, like “flashing” and they’ll also show up with red skin, red veins in their fins, stop eating and develop a slimy skin. (All those symptoms happen in pH crash, too)

Parasites may be controlled by several medications, such as Salt, and API’s General Cure.

-Water quality is 3 to 1 over parasites for the source of illness. Yes and that’s annoying. People OFTEN contact me and ask what medicine to use for this or that symptom they’re seeing. Or the medicine isn’t working. The koi gets worse. So I ask them what the pH is. What the Ammonia is. What the Nitrate is. And they get back to me with a number WAY out of range, they fix that, and no medicine was even needed.

What you can do: A video introduction to the major categories of parasites and some treatments worth knowing.

8. Bacterial Infections – Rot

What sores mean:  Sores just mean the fish have “gone through something” that broke their immune system. Cold water, over crowding, high nitrogen levels, a low pH, wintertime, low dissolved oxygen, cold water, excess handling and parasites chewing on the skin are all very common causes. Just exposure to bacteria (even the baddest of the bad) don’t CAUSE bacterial infections.
What you can do: You have to diagnose what happened, what “they went through” and then fix that. Provide an optimal environment. And then perhaps apply antimicrobial treatments to the water, in the food, by injection. Literally everything you would NEED to know in order to deal with bacterial infections is at my DrJohnson Youtube page. But also:

Ulcer Disease I, II, III

What you can probably not do: You can’t save fish that are:
-Too far gone
-You may not be able to obtain or give injections of antibiotics but they work great. Perhaps you could find a vet that can help. Injections for really valuable ones
Water treatments for other cases like Potassium permanganate or Chloramine T.

9. Viral Infections

What viruses are there, in general: If you don’t get more fish, viruses aren’t a “thing” for you to worry about. But there are viruses out there which will kill almost all your fish. The main one is Koi Herpes Virus. It depends on water temperatures to kill fish. Under 70 degrees Fahrenheit, it’s inactive. Above 80 degrees Fahrenheit, it dies off. Fish are saved. If you quarantine fish according to the video mentioned above, and the fish achieve a temperature in the low eighties, Koi Herpes Virus is a non-issue.
Other viruses include viruses that cause warts, little waxy droplets on the skin, and are not lethal. Spring Viremia of Carp is a common disease that appears to be endemic (in everything) to north America and causes depression of the immune system potentiating bacterial infections. You wouldn’t know if your fish had this, because if you test for it, you’re likely to get a positive, and then you will have your pond closed, killed off, and quarantined.

10. Shutting down for winter

When not to feed:  Koi and pond fish do better in very cold water WITHOUT food in their tracts. It’s a good idea to suspend feeding when the water temperatures sail down below 55 DF — IF you can anticipate the temperatures are going to decline FURTHER like a typical temperate climate. (North American near freezing) – However in Portland and other geography, the ponds might hit 55 and NOT go down, so those aren’t “heading to icy” and so if the temperatures are going to hover above 40 DF you should feed Cheerios.

When to shut down the filters?   You can keep your filters running unless it’s going to freeze and you have to “winterize” the filters, so you ought to talk to your installer or filtration manufacturer about how to deal with temperatures prevailing in your area. If your filter has a return under water or which won’t super cool the pond, you can leave it on. The biological activity of the filter will be sadly lacking so feed less, or feed Cheerios.

How to turn water over
-When you don’t really have to:   When water is in the low forties and lower, it carries all the oxygen it can. So water movement isn’t a “thing” at that point. I mean, SOME water movement is important but that’s mainly for gas release (CO2 etc) rather than Oxygenation.
-Striking the ice –  It is a myth that if you strike the ice over pond fish, they will die or go deaf. In fact, sometimes fish die under the ice and that had NOTHING to do with someone breaking the ice. Usually it’s the fact that they even HAD to break ice. Ice need to have a hole or gas exchange gap in the surface. If you have to use a floating cattle trouble heater, do it.
-What Springtime means: Springtime is tough on Koi and pond fish because typically:

  • The fish have gone hungry all winter
  • The fish have been cold and their immune system is warmth-fired.
  • Parasites don’t care if it’s cold and can strike in cold water with extra vengeance.
  • Water bacteria (purification bacteria) are largely dormant so water quality is at it’s lowest.
  • A winter’s worth of fish excreta and plant material / last year’s mulm are all suspended in time, and break down as soon as water temps rise. It’s a surge in algae / bacterial nutrition.

Twenty Steps to Fish Health Free Ebook Read online!

I’m also going to make this readable e-book available in print format but you can also read it online. It’s just 14 pages and there aren’t images. It’s succinct and updated per 2019

What you’ll see is a book(let) that steps you through the “process” I’d actually engage on a house-call to your pond if you called me. Twenty assessments

Click the picture of the book below, and you’ll be whisked to the online, readable version. Bookmark it for later this year, in the Spring if your fish get sick.