Mystery Illness

[PaleBluePoet]

Hi there. First time back in a while and first time in this particular forum. I've been a hobbyist for the past 5 years. Wouldn't call myself an expert, but perhaps not quite a dummy, either! ; )

Quick preface: 72 gallon bow front. Planted. 50% water change per week (I live in Seattle). Water quality is definitely not an issue. Barely measurable phosphate, nitrate, nitrite, etc., etc. I keep an immaculate tank (yup, I'm compulsive!). UV light. Magnum filter. Change carbon every week. UV and filter far surpass needed capacity.... why use an M80 when you can drop a nuke! lol


Something has been killing my fish. There isn't any obvious cause. I've had fish die from all kinds of afflictions over the years, but this one has me puzzled. It only affects my barbs (I have clown and sidthimunki loaches, too, and one Krib-like cichlid--but not a krib). The fish will show some level of distress first. This is usually exhibited by some "hiding" behavior and some fairly subtle struggling. Then the fish gets better. They interact fine, feed fine, etc.... even during the symptomatic stage. Then they go through another period. Sometime they then become fine again, but usually they just die at that point... nearly overnight. They die at the rate of about one every 2-3 months.

I read an article recently in TFH that discussed the possibility of something, for lack of a better term, they were calling Fish HIV. That's what this seems like. I'm hoping not, because the article also said there is absolutely no cure... they'll just slowly, but surely die. I've tried wide-spectrum antibiotics and fungal/bacterial treatments, just as a precaution, but the fish just keep dying. Very, very slowly.

One last thing. I add a very small amount of crushed coral to my filter media. It solved a long standing problem of mine around unstable pH. I no longer have a pH problem. However, is it possible that this stuff is affecting the fish somehow when it's leaching into the water through the filter? Just a wild thought.

This is maddening. Any ideas? Many thanks.

 

[Lateral Line]

Crushed Coral will be raising your pH and hardness. Barbs are soft water lower pH fish, but unless your pH has gone sky high, which I doubt, it seems unlikely. I don't know what the water is like in Seattle, nor what your pH problems were, or why, but generally, unless you have VERY soft water, like less then 3 degrees for example, it should not be necessary to buffer a freshwater tank. What is/was going on there?

How old are the fish that are dying? How old were they when you got them? Have they been in the tank a long time? I think you can guess where I'm going with that one...!

Barbs are sensitive to Nitrogen pollution, indeed, some people with delicate fish stick some barbs in as "indicators" as they tend to go into a subdued nose down attitude if there are problems faster then most other species. Are your test kits old? Are they reliable? Ammonia and Nitrite should be zero, not just low.

Nitrate becomes a problem at high concentrations, (say over 40ppm), and some places have a lot of nitrates in their tapwater. Nitrate is the end point in normal tanks of the biological filtration cycle ammonia->nitrite->nitrate. If you are not seeing nitrate, where is it going or is it not coming?

When changing your filter media, (carbon is pretty useless unless you have a specific occasional need like clearing out meds), are you being to thorough, i.e. wiping out much of your bacteria?

There are articles in most fish magazines about weird and dreadful diseases pretty much every month. There are people on the board here that jump to the "disease" issue whenever a fish looks off colour. In practice 99% of fish medicated for "disease" are actually suffering from an environmental issue.

Questions to ponder.

 

[gowing238]

I was just wondering, you mentioned you change your carbon every week. Does this mean you are adding medications to the water with the carbon in the filter? You probably know this but the carbon would remove the medication making it otherwise useless!

 

[PaleBluePoet]

First of all, thanks for the comprehensive reply.

Seattle has incredibly soft water. As in absolutely no measurable carbonate hardness. That means that once you put water in your tank, the pH begins to drop. The water comes in at 7.5/6 and drops in a day to 7.0 (mostly because the water left in the tank is around 6.8). So I've added about a tablespoon of crushed coral to buffer the water. I had originally used a pH stabilizer, but I just don't like to add chemicals to my tank if I can help it. This is a problem for nearly anyone in this area. With the coral I maintain a level of 6.8 in my tank. Very stable.

I should have been more clear: nitrate levels are barely measurable in my tank. There is rarely any measurable phosphates, but when there are (like .00000001) I use a phosphate remover. It's not great for my plants, but any measurable phosphates results in an algae bloom. I've never had any measurable nitrite at all, except a few years ago when I first cycled the tank.

I have a different view on carbon. Yes, it IS useless when changed once a month. But carbon media changed once a week very much has an effect on the tank. It smells better! Plants have a tendency to bring a little bit of a "verdant/earthy" smell to the tank.

The fish are about a year old.

My tank is well-aerated, so I'd be surprised if I'm dealing with nitrogen, especially considering the plants, changed water each week, and the amount of saturated nitrogen. My test kits were old... but I've been using new ones the past few months with the same results.

The bacteria in the tank shold be fine. I don't do a whole lot of scraping. I have a lot of plants, rocks, and a little drift wood in the tank (sanitized African wood). I always keep about a 1/3 of my filter media when I change water. Finally, no tell-tale cloudiness which would indicate a rebalancing of the bacteria.

Hey, these were all great things to mention, so many thanks for your input. Like I said, I keep a very, very clean and very regulated tank. It's really tough for me to believe that it might be environmental, because all of the tests give it a very clean bill of health. I had problems, like most hobbyists, when I first started five years ago with environmental issues. It took a few years to figure it all out. But when fish are affected by water quality, the response is usually pretty predictable. They start to get ich and other fungal infections (because of compromised immune systems) and generally exhibit symptoms long before they die. This death is very quick. I did forget to mention one key thing: the fish nearly always have a very slight bloating to them. Nothing like the pine cone effect, but a very, very slight, barely noticeable distension of the stomach area. You really have to know the fish to even see it, but it's there.

Thanks again, for some great comments!

 

[PaleBluePoet]

I was just wondering, you mentioned you change your carbon every week. Does this mean you are adding medications to the water with the carbon in the filter? You probably know this but the carbon would remove the medication making it otherwise useless!

I always turn off the filter when adding medications, unless otherwise specified. Good catch, though! Thanks.

 

[mikev]

Hi,

A similar story here (New York). 8 barbs slowly went down to none, over about a year.

Making it brief, the situation got steadily worse, spreading to multiple tanks and affecting other species.
Eventually it has been traced to tap: it contains a toxin (still undetermined) that does this. The amount of toxin has been slowly rising as to produce faster kills and clearly correlate with W/C's; I further got a confirmation of a tap problem from a couple of other people who know what they are doing.
I ended up installing an RO/DI system (a 7-pass monster) which seems to solve the problem...too recent to be conclusive, but it looks like the issue is over and I got six new barbs to make sure this is the case.

I'm not suggesting you have the same problem, but mine (that eventually killed >50 animals of various species) started with Barbs too. If all else fails, tap is something to look at.

A bit more info:
This thing seems to be very species-specific, even very closely related species are affected differently.
(It would be interesting to know which Barbs you have).
Clown loaches seem to be not sensitive to the toxin here *at the current levels*.
I don't have sids, but most of other loach species that I keep are sensitive.
Many "normal" species are not sensitive, there were no losses in say Plecos, Rainbows, most Danio sp kept...
Carbon or inline GAC does not remove the toxin (or enough of it).
NY Water is similar to yours: very soft (so I use corals), main diff is that the phosphate level is high.

Good luck.

 

[Lateral Line]

When I say Nitrogen pollution, I refer to ammonia/nitrite/nitrate, N2 is not really a problem, at least in regular tanks. I'm still curious as to where your nitrate is going. In a really heavily planted tank it will go of course, but we tend to be talking about high light, CO2 injection, EI type systems.

Presumably not chloramine Mike, that is increasingly common in urban areas to keep the pipe networks clear of helminths etc., but is pretty toxic to all species.

Is there any commonality with the species? Are we talking African, Indian, Sri-Lankan, SE-Asia, Malayan species? I recall a paper a while back, was one of those Indian sites Mike, that discussed the toxicity tolerance of numerous species to various metals. Unsuprisingly, species from drainages where there were known ore deposits tended to be more tolerant than those that came from barren drainages, (thank you captain obvious!).

Very soft water is a better solvent then hard. Hard water tends to coat the insides of pipes with scale, so issues like copper, and metals from soldered joints are less important. I've never lived in a soft water area, most places I've been, you didn't pour water out of a jug, you cut slices of the stuff, (chalk boreholes, over 500ppm Ca++ pH->9).

Total aside, I like the earthy smell from my very heavily planted tanks, has a naturalness about it.

 

[scooterchick]

Is a 50% water change a week a bit excessive or necessary? You could do 25% twice a week, giving the same result but lessening the stress on the fish. 50% is a BIG change i the one go.

 

[mikev]

50% W/C btw may be indeed too stressful for Barbs. Unless the tank is severely overstocked, it is also unneeded.

Presumably not chloramine

Not them. Firstly, they do not seem to be present at all, secondly I use conditioners that take care of them.

Before yesterday, I was certain that it is As (lots of details matched it and nothing else I could think of matched all the details)... but yesterday I got a test kit for it and it shows zilch. So right now, no ideas.

I don't have enough of the variety here to really derive patterns: most fish is Asian (loaches+dither), the only other is a few Plecos.
What is certain is that Balitorids are the most sensitive, but the current level of toxin kills even Botia's.
But the toxin is very selective: most of my Danio's don't seem to care, but Glowlights (D.Chorpae) are quickly killed by W/C's. Among Balitorids Gastros appear to be totally safe, everything else is not, but to various degree.

The most sensitive fish are lizard-type loaches and gobies.

With Barbs, my problem was with Odessa's. It appears that Rosies are not sensitive, but I have no idea about other species.

One general rule that seems to hold is that high metabolic rate animals (faster/more moving, and/or high-O2-requirements animals) are the most affected. No losses occurred with the lazy types like plecos or kuhlis. Smaller fish is more vulnerable than large in most cases.

Guppies appear to be quite vulnerable too (I don't keep them, but someone else who knows what she is doing was having massive losses with them lately).

This is the overall picture. Unfortunately, took me very long time to even realize the tap connection,...lots of time was spent on treating diseases that were not.

 

[Lateral Line]

Unless the tank is severely overstocked, it is also unneeded.

It depends on the tank regime. There are a lot of heavily planted tank owners that follow the EI principles which, to a purist, requires a 50% water change per week. The OP does say plants, but if he was an EI man, I'd have thought he'd have mentioned that, although I am still curious as to where his nitrates are going. With EI, you actively add NPK, (nitrates, phosphates and Potassium), and use the large water changes to remove excessive salts.

You noticed anything like this bloat Mike? I'm wondering excessive water in the tissues to try to osmoregulate a metal ion.

The high metabolic rate link may suggest an antagonistic relationship with the O2 carrier. Larger fish would have a naturally higher tolerance simply because they have a larger reserve of carrier, low metabolic rate fish, a higher tolerance because maybe their excretory mechanism can keep up with the problem?

I certainly glad you've ruled out As, at least at your site.

Be interesting to see what stock the OP has lost.

 

[mikev]

In re 50% W/C's: I distinctly remember recommendations to avoid large W/C with barbs. With Odessa's, I've discovered that even with 25% W/C, their coloring is better if I add new water slowly...letting them acclimate. It may be a good idea for the OP to post the parameters before and after a typical W/C to see how much they change...if noticeably, this well may be the cause.

You noticed anything like this bloat Mike? I'm wondering excessive water in the tissues to try to osmoregulate a metal ion.

Nope. Very few symptoms, in most cases, a fish is perfectly fine one day and dead the next. There were few cases of aberrant behavior for 2-3 days prior to death: inactivity/heavy breathing, all on larger fish. On necropsy's we saw liver damage (this is one reason I was thinking As).

The high metabolic rate link may suggest an antagonistic relationship with the O2 carrier. Larger fish would have a naturally higher tolerance simply because they have a larger reserve of carrier, low metabolic rate fish, a higher tolerance because maybe their excretory mechanism can keep up with the problem?

I think so too. But it does not help in determining what the toxin is, and there are a few weird abnormalities between similar species: why D.Choprae are sensitive while only a bit larger D.Kyahtit are not?

The other interesting detail: the levels of toxin are rising and this seems to have produced a change in how it works. Before, it was killing slowly, without any visible correlation with W/C's. Lately, the correlation is obvious: if I were to make a 20% W/C with tap now, I will see a disturbed fish within a day...and with only one exception it will be dead soon. (I managed to pull one back with a few large W/C of RO water).

I certainly glad you've ruled out As, at least at your site.

Nay, I'm really dissappointed, I have no good theories of what this thing is anymore....and I'd really like to know.

Be interesting to see what stock the OP has lost.

Yeap, quite so.

 

[Lateral Line]

Does your water utility have any comments? I presume people are drinking this stuff.

 

[mikev]

It is NY. The water utility is buried under layers of bureaucracy and does not publicize its phone #.... After daily calls and filing about twenty requests and complains I broke through and they are supposed to come in to do a water test on Sep 6, with the results in October. Almost certainly, the results will show nothing.

As for people drinking it: possibly millions, it is the same water system. The moment I realized that there is something cute in the tap, we got a DI filter for ourselves. Even the dog drinks DI water now.

 

[mikev]

LL,

too bad that the OP did not reply....

On my end, Copper has emerged as the most likely cause. In fact, water report shows Copper at about 10% of the lethal level (for one species), and there are good reasons to think it is both higher and more lethal than documented.

I'm still trying to understand the picture better (it is complicated), but it seems that it would be wise to check Cu concentration in all cases of unexplained deaths of loaches and small cyprinids of any kind. I have no idea if it is toxic to other types of fish...seems to be very toxic to gobies and non-toxic to plecos, but I don't have any other types of fish to check.