Emergency: Healthy Tank, Fish Died

[lkunz]

We have two aquariums, a five gallon and one ten gallon, both of which have seemingly non-toxic water. Here are the stats for both -

5 Gallon:
Ammonia 0, Nitrite 0, Nitrate 60 ppm

10 Gallon:
Ammonia 0, Nitrite 0, Nitrate 60 ppm

Both have finish cycling within the last month and have not been overstocked. Yesterday, we added a new heater into each aquarium. The type of heater is a Marineland Dual Temp 5-20 100 Watt Precision Submersible Heater.

Today, as we went to feed the fish, we discovered that all the Tiger Barbs in the five gallon tank are dead. In the ten gallon, two of the Red-Eye Tetras are dead. The rest of the fish in the ten gallon are lethargic, but did eat when fed.

We installed the heaters as a precautionary measure for the upcoming winter. It does not appear that they even turned on overnight. Could there have been toxic chemicals on the heaters that caused the fish to die? If so, and any toxins are in the water, what do we do now? If you do not think this is what happened, please shed some light.

Thank you in advance for any advice you can give.

[tomm10]

60ppm for nitrates is a bit high I think. I'm not sure if that would kill fish like that but I've been under the impression that you should shoot for under 20ppm for nitrates and get that by doing regular water changes.

Do you have thermometers on the tanks? You should have one on the opposite end of the tank from the heater. The fish should be able to take a bit of a range in temps but if the heater was set too high or was defective that could have had something to do with the deaths.

Have you added anything recently? Decorations? Meds?

Definitely do a good water change. Probably 20% to get those nitrates down.

[OrionGirl]

I always wash everything before it goes in my tank. It is possible there was something on the heaters, but it seems unlikely. You may want to check the heaters for cracks, which could be releasing electricity into the water. Unplug the heaters before reaching into the tank--many people can confirm that reaching your hand in is a nasty way to discover a cracked heater.

How long had the fish been in the tank? Could be they were suffering from an ailment when purchased. When was the last water change? The nitrate levels are pretty high for both tanks. While nitrates themselves are seldom toxic, they are an indication of other waste products that we can't easily detect. Regular water changes to keep the nitrates in uplanted tanks below 20 ppm are a good idea. If the fish were a recent addition, the high levels of these other toxins could be responsible for their deaths as well.

While not the cause, 5 tiger barbs in a 5 gallon tank is a high fish load, and too small a territory for these fiesty little guys. They need more space to avoid being stressed.

[lkunz]

Thank you both for the input. Three of the tiger barbs were purchased on Friday, so we returned them to the pet store. The manager also said to check the temerature, and it is steady in both tanks at 78 F. The ten gallon tank is moderately planted, and the five gallon is mildly planted. This creates low alkalinity which we sometimes increase by using kH up. We have not done this to either tank in over a week. Otherwise, we have not recently added any decorations or chemicals to either tank.

The five gallon originally had Red-Eye tetras, used for cycling, that have been moved to our ten gallon. The five gallon has been cycled for two weeks and the Tiger Barbs have been there for three. Our last water change for both tanks was on Friday. In the five gallon, we did change the filter cartridge for our bio-wheel filter (not the bio-wheel itself). Could that have contributed to their deaths?

The five gallon was intended as a temporary living situation for the tiger barbs. We are getting a bigger tank within the month in which to transfer them. Our biggest concern is what to do now. Obviously, the water is unsafe for fish to live in. Do we need to do a complete water change, rinse the decorations, and start over? Or do we need to wait it out and then add more fish? If any undetectable chemicals have gotten into the tank, how can we get rid of them?

We do regular water changes to keep the nitrate levels down. Is there any thing else we can do to bring them down? Thank you for any additional advice.

[OrionGirl]

More frequent water changes will help reduce nitrates, but if these are planted tank, I think it's odd that the levels are so high anyway. My planted tanks show 0 nitrates, even with fertilization. You may want to have your water tested by a different kit, just to confirm accuracy.

Since there was a recent addition, it could be that the fish introduced a pathogen. If this is the case, leave the tank without fish for a week (you'll need to feed the bacteria with ammonia) and run carbon. Carbon will remove most chemicals within 2-3 days.

Did you rinse the filter media prior to putting it in? If it's one that has carbon, the dust should be removed before use. This dust can accumulate on gills and impair the fishes ability to get oxygen from the water.

By replacing the filter media, you did remove some of the beneficial bacteria. It should not have been significant enough to kill the fish, especially since the ammonia still tests at 0.

The red-eyes could have succumbed to the ammonia/nitrite burns they suffered during cycling. The damage caused by exposure to high levels of ammonia or nitrite is not always immediately fatal, but kills them down the line.

[anonapersona]

What was the tank temp before adding the heaters?

A rapid change in temp could have done it. I've read that tank temp changes should be 2 degrees per day, but don't know what increase might be fatal, certainly it would have to be far more than that.

[29gallonsteve]

You are using pH up...

I recommend against using any of the Up/Down products unless you have some very unique circumstances...generally, all it causes are pH swings that can affect the fish (especially if your tap water is drematically different from the water in the tank).

Thanks,
Steve

[lkunz]

The temp. in both tanks was 80 yesterday (before the heaters) and is at 80 today. We rinsed the heaters before we added them to the aquarium. The heaters only turn on if the temperature gets too low. We added them because the weather has been cooler at night. The last 24 hours have been warm, though, so the heaters should not have kicked in at all.
Our filter cartridge contains a sponge and activated carbon. We rinsed the cartridge thorougly in cold water and then saturated it in dechlorinated water before adding it to the tank's filter. Are there any other precautionary mesaures to take when switching filters?

All the barbs in the five gallon died. There are two plants in this aquarium and several in the ten gallon. It is my understanding that plants will eat alkalinity (kH), but that low alkalinity can agitate/stress the fish. We were advised by our local pet store that there is no natural way to increase the alkalinity, which is why we have been occasionally adding kH up. We do not use pH up or down and try to avoid chemicals as much as possible. In the ten gallon, one of the fish that died was the smallest Red-Eye but not cycled in the other tank. All the other fish in the ten gallon (Red Eyes & one Black Skirt) are not swimming much but usually do not this time of day. None are breathing erraticaly or show any other strange behavior.

As far as the nitrate levels, the pet store tested our water sample when we took three of the barbs back. We will continue to do water changes and may get another test kit to determine if ours are testing correctly. Also, how can I feed ammonia tothe bacteria in the next week or so (while the tank is empty)?

Thanks again.

[OrionGirl]

Regular water changes should be all it takes to maintain the hardness of your water. Plants can deplete the water of certain elements, but this takes time and no water changes-longer than your tank has even been set up. There are other ways to stabilize kH, but for most tanks regular water changes will be enough. I recommend you monitor the kH on the tank for one month, then determine if any treatment is needed. What is it reading currently? What does it read from the tap?

Rinse filter media in the old tank water, or dechlorinated room temp water.

Add enough straight ammonia (yes, the bottle stuff sold as a cleaner) to read about 1-2 ppm on your test kit each day. Can't do this with fish in there, but it will keep the bacteria alive. This is 'fishless cycling'--meaning no fish are ever exposed to toxic levels of ammonia.

Sorry we can't really specify exactly what killed the fish. There are many possibilities and little to go on.

[29gallonsteve]

In the interest of covering all the bases, what product did you use to de-chlor the water/filter?

Thanks,
Steve

[lkunz]

We use Chlor Out, made by Wardley Watercare, to dechlorinate all our tank and decontamination water.

Here are the readings for our water straight from the tap:
pH - 7.0
Alkalinity - 60 ppm
Hardness - 200 ppm
Nitrite - 0 ppm
Nitrate - 10 ppm

We actually have been monitoring all our levels from the time we started each tank. We test every three days and keep a log. T he current readings are as follows:

From our 10 Gallon:
ph - 6.8, Alkalinity - 20, Hardness 200, Nitrite 0, Nitrate 60 ppm
The alkalinity in the ten gallon has fluctuated between 60 and 20 in the past month.

Readings from the 5 gallon:
ph - 7.0, Alkalinity 40, Hardness 200, Nitrite 0, Nitrate 60
The alkalinity in the five gallon has fluctuated between thirty and sixty.

The ammonia in both tanks reads zero.

[sumoschro]

hmm.....did you add any medicine/other treatments to the water or fish that you might have overdosed?

[lkunz]

Here's an update on our ten gallon. This morning two of the Red Eyes were dead but the rest appeared fine. We did a water change, as was suggested, about an hour ago. Now, one more is dead and the other Red-Eyes seem to be folllowing suit. Our two Mystery Snails and Black Skirt appear to be doing fine at the moment. There is no definite sign of any sickness. Their gills are colored normally, they are just at the top gasping for air. This morning they all happily ate tubiflex worms. We attempted to feed them tropical flakes tonight but none ate except the Black Skirt. We truly have no idea what is happening but it is sad to watch.

[yashinfan]

The fish are at the top gasping for air?!! This is not a good sign at all!! Were your fish doing this in the other tank before they died?? Okay, do you have enough surface agitation? ie: air pump, powerhead, etc... ?? Something is causing these fish to gasp and that's probably what is causing them to die!

[anonapersona]

Has the area had any strange weather recently? Floods? Has the water company done any major work -- call them. They might use different chems after major line repars.

[Ghetto2k4]

what kind fish u got in the tank? and how many?

when was the last time u did a water change?

have u test the tank tonight? for ph,ammonia, nitrite, nitrate

how long as this tank been setup? is it new?

[lkunz]

We went out to get some bloodworms for our frog (and we were tired of watching our fish died slowly). Upon our return, there are only three still breathing. Two Red-Eyed Tetras and our Black Skirt Tetra. Our two mystery snails seem to be okay for now. Our plants don't seem at all bothered either.

The only strange weather was the hurricane about 6 weeks ago. The repairs from that have been competed for weeks. (We lost two fish to the hurricane during the power outage, but that wasn't as puzzling as this.)

The most upsetting thing is we cannot seem to figure out what we have done differently than before. At the pet store, we asked about any other people had complained of dying fish. They replied "no." We haven't changed any cleaning supplies, hand creams, aerosoles, etc. that we've used before.

At this point, I'm ready to take everything out (that's not living) and boil it. I'd rather start from scratch than deal with this mystery.

Thank you to everyone that has given advice and support. I'll keep you posted on any changes. ;)

[OrionGirl]

The fact that they died so quickly after a water changes makes me think the water source may be contaminated, or more heavily chlorinated than previously. If you know there are not chloramines in the water, try aging the water for 2 days in a large open mouthed container, prferably with some agitation from an air stone. Frequently, the water company will increase the amount of chlorine treatment following repairs, and they do not announce this. If others in your area use the aging process to remove chlorine, they wouldn't have had any problems.

[lkunz]

We called the water company and they said no changes have been made in the last few days. However, since the hurricane the entire makeup of our water has changed (lower kH, harder, and higher nitrate levels). I did request a report from the lab and will get a makeup of the chemicals used, so that should be helpful.

Anyway, two of our fish in the ten gallon have survived, one red-eye and one black skirt. They are in need of companionship but do not seem to be any worse for the wear. We will add about three more red eyes this weekend.

We are keeping the ammonia levels up in the five gallon and will wait a week or two before adding more fish. We are also doing as suggested and “aging” our water before adding it to the tank.

It was very sad and shocking to watch twelve fish die in twelve hours, but thank you to everyone for advice and help. We will continue to update and post on the status of the tanks. Thanks again.

[anonapersona]

Originally posted by lkunz
Thank you both for the input. Three of the tiger barbs were purchased on Friday, so we returned them to the pet store.

So, the fish deaths are following the addition of new fish to the tank?

Perhaps we are all looking at the wrong thing, it may be just a coincidence that the water change was on Friday also.

You took new fish from the pet store and added them to a tank that had 60 ppm nitrates, that might be rather shocking to a fish. A badly stressed fish could be subject to all sort of normally benign parasites, especially if recently netted and perhaps having minor abrasions on the slime coat. So, parasites or bacteria attack, polluting the tank and this is transfered to the other tank, by nets or other shared items like siphoning hoses.

I suggest that you start using the 5 gallon tank as a quarantine tank, with separate nets and hoses and so on.

Pick out the new fish, but do not add them to the large tank, hold them in the small tank for 4 weeks, then transfer them to the bigger tank. Repeat until the bigger tank is fully stocked. You will be limited in how many fish you can buy for the 5 gallon tank.

As you have found out, the fish store guarantee will cover the loss of the newly purchased fish, but it will not cover the loss of the other established fish you lost after introducing new fish to the tank. If you use the Q tank, you will not lose any established fish.