Water-change killed my fish??

[quinnARIUM]

When changing water in smaller tanks, using a bucket can be easier (provided you can carry them; I could never have done this during the six-plus months of my recovery from cancer surgery last November), and it is simple to add the number of drops per gallon the conditioner requires. A 3-gallon bucket for example, which is the basic size I use, requires three drops of the API Tap Water Conditioner. When using a Python and filling direct from the tap, I add the conditioner as the refill begins, directly into the tank.

I agree, I am sure that conditioning water in a separate container is safer and I will look into that more, but for now I would really like to get my "python" water change system working (the reason I am quoting python is because it is actually just hose and a filter inlet siliconed together).

Could the chlorine actually kill that many fish, even in small doses? My tap water'a chlorine levels rarely raise above 0.8 mg/L although I understand that it can fluctuate.

Follow up question: I really would like to get a school of discus fish for this aquarium. It feels unsafe to put them on after having such a large incident in the aquarium, but in all other respects the tank is doing really well. Is there anything else I should check before adding discus? How sensitive are discus to small amounts of chlorine or water parameters? I know they are one of the more difficult fish to keep, but it also seems like bigger fish do better with slight fluctuations.

 

[Bruce Leyland-Jones]

Follow up question: I really would like to get a school of discus fish for this aquarium. It feels unsafe to put them on after having such a large incident in the aquarium, but in all other respects the tank is doing really well. Is there anything else I should check before adding discus? How sensitive are discus to small amounts of chlorine or water parameters? I know they are one of the more difficult fish to keep, but it also seems like bigger fish do better with slight fluctuations.

You really do need to do some serious research on Discus.

 

[Byron]

The instructions on the seachem prime bottle says to add the dosage required for your full tank volume if adding tap water directly into the tank.

Yes they say that, but they are selling the product and if they convince you to use twice as much as you need...???

I asked Neale Monks about this, and he said there is no real benefit in using more than necessary for the volume of fresh water being added, but most people probably use more than they need out of over-caution, thinking it is better than using too little. If the conditioner is able to diffuse across the cell membranes with the water entering the fish by osmosis, it is preferable to use no more than needed. Seachem also says you can use up to five times the amount and it is "safe" for fish, but I don't define "safe" the way they seem to--if the fish do not die within minutes, it is safe. Not my thinking.

 

[Byron]

Could the chlorine actually kill that many fish, even in small doses? My tap water'a chlorine levels rarely raise above 0.8 mg/L although I understand that it can fluctuate.

This past week there have been a couple threads involving this question of chlorine and chloramine, and how to deal with it. Many areas are now using chloramine instead of chlorine, and chloramine is a bit stronger and not as easily dealt with as chlorine in general, but let's deal with chlorine since you asked about it.

Yes, chlorine burns the gills of fish, and quite rapidly. It can depends upon the level of chlorine inn the water, and the size of the tank. In a 4-foot 90g tank for example, changing say 5 gallons might not affect the fish, but in a 20g tank changing 5 gallons without dechlorinator could kill them quite rapidly.

A level of 0.8 is significant, this is roughly the level in most water systems according to the members who posted in the other thread(s). I know that I have twice in 30 years began to fill the tank (70g) and forgot the conditioner, and within seconds the fish were hovering near the surface at the opposite end of the tank...I instinctively knew what had happened, and I squirted in the conditioner and within a minute or two the fish were clearly relieved. I was lucky to have seen it before it was too late, but I do have a habit of observing the fish when I refill using the Python from the tap directly.

 

[quinnARIUM]

This past week there have been a couple threads involving this question of chlorine and chloramine, and how to deal with it. Many areas are now using chloramine instead of chlorine, and chloramine is a bit stronger and not as easily dealt with as chlorine in general, but let's deal with chlorine since you asked about it.

Yes, chlorine burns the gills of fish, and quite rapidly. It can depends upon the level of chlorine inn the water, and the size of the tank. In a 4-foot 90g tank for example, changing say 5 gallons might not affect the fish, but in a 20g tank changing 5 gallons without dechlorinator could kill them quite rapidly.

A level of 0.8 is significant, this is roughly the level in most water systems according to the members who posted in the other thread(s). I know that I have twice in 30 years began to fill the tank (70g) and forgot the conditioner, and within seconds the fish were hovering near the surface at the opposite end of the tank...I instinctively knew what had happened, and I squirted in the conditioner and within a minute or two the fish were clearly relieved. I was lucky to have seen it before it was too late, but I do have a habit of observing the fish when I refill using the Python from the tap directly.

Thanks you!! This was really helpful. Sadly, upon reading this, I believe I have many of my fish have died from chlorine. I think I just jumped so headfirst onto all the aspects of water chemistry that I failed to fully address chlorine/chloramine.

Have you ever heard of larger fish being more resistant to chlorine? What confused me most about the incident was that the apisstogrammas pair and bamboo shrimp survived. I thought the shrimp would be most sensitive to some sort of water fluctuation.

--I think I need to find a new way to dechlorinate my water. Whether it be pumping it from a separate container, or dechlorinating more thoroughly during a water change.

 

[Byron]

Follow up question: I really would like to get a school of discus fish for this aquarium. It feels unsafe to put them on after having such a large incident in the aquarium, but in all other respects the tank is doing really well. Is there anything else I should check before adding discus? How sensitive are discus to small amounts of chlorine or water parameters? I know they are one of the more difficult fish to keep, but it also seems like bigger fish do better with slight fluctuations.

The size of a fish does factor in to how they can be affected by various issues, and generally speaking the smaller the fish the more critical this is because of their increased metabolism. However, discus are not all that large, and regardless of their size they are sensitive to various things more than many other species can be, depending. No fish should ever be subjected to chlorine, or varying water parameters (these are GH, KH, pH and temperature) or varying water conditions (ammonia, nitrite, nitrate, etc). Any of this can seriously harm fish; even if they live through it, internal damage may well have occurred and this can cause the fish to succumb to any number of other problems that they would normally have been able to easily handle without trouble.

Before adding discus, make absolutely certain the tank is established (not just cycled, but established) which will mean the GH, KH, pH and temperature do not fluctuate or vary at all, and ammonia and nitrite are zero and nitrate is as low as possible, and never increases between water changes. Cichlids are now known to be sensitive to nitrate, and levels at 20 ppm or higher can be very detrimental. If you do not have nitrate in the source water, then you should be able to maintain an aquarium with nitrate in the 0-5ppm range, and again, make sure this never gets higher before the next water change. Substantial and regular water changes are intended to maintain stability in water parameters and conditions.

 

[quinnARIUM]

Yes I agree that I should continue testing. Sorry I know I sounded a little trigger-happy to put the discus in the tank and I am not planning on getting them until I am certain water fluctuations will occur. The tank has been set for 6 months, nitrate generally at 0 (although admittedly the bio load is very small right now), so I feel like this biggest thing I need to resolve is my water change system. How can I be sure the water is thoroughly dechlorinated? Should I add dechlorinator slowly as it fills up, or all before and mix it around, or afterwards?

 

[Byron]

Yes I agree that I should continue testing. Sorry I know I sounded a little trigger-happy to put the discus in the tank and I am not planning on getting them until I am certain water fluctuations will occur. The tank has been set for 6 months, nitrate generally at 0 (although admittedly the bio load is very small right now), so I feel like this biggest thing I need to resolve is my water change system. How can I be sure the water is thoroughly dechlorinated? Should I add dechlorinator slowly as it fills up, or all before and mix it around, or afterwards?

I think we've all covered the chlorine issue...but you need to add the appropriate amount to the fresh water if you use a bucket or some sort of holding container, using enough for the w3ater in the bucket each time, no more or less. If you use the Python method (hose direct to the tap), add the required amount of conditioner to the tank just before you start to refill. Conditioners work instantly.

 

[Colin_T]

Could the chlorine actually kill that many fish, even in small doses? My tap water'a chlorine levels rarely raise above 0.8 mg/L although I understand that it can fluctuate.

Yes. As mentioned previously, water companies vary the amount of chlorine/ chloramine depending on conditions, which can change daily. You might normally have 0.8mg/l of chlorine but if the company does work, or you get a sudden heat wave or pollutants in the water supply, they will not hesitate to dump a heap of chlorine in the water to kill anything that might be in it.

I used to fill my tanks directly from the tap, like you do. I would add a double dose of dechlorinator for the entire tank volume. One day I did a water change like usual and filled the tank. The dechlorinator was already in the tank before I added tap water. Within 5 minutes every fish in the tank was gasping at the surface or dead. I contacted the water company and they had done work on the pipes in the area and increased the chlorine to kill off any nasties that might have gotten into the water. Since then I have never used chlorinated water in an aquarium because it can change daily due to environmental conditions that are out of your control. The only way you can be 100% certain is to put the water in a bucket and test the chlorine level every time you do a water change. Even then, water companies add other stuff that won't show up on a chlorine test kit.

For the last 20 years in Perth, the water company has been adding something that leaves a hard white residue when the water evaporates. It sets like concrete and when I chip some off and test it, it is not calcium and does not dissolve in acid water. The water company denies adding anything like that but it appears if I leave a bucket of water to evaporate and it isn't from the bucket or surrounding air.

People get away with adding tap water and conditioner to a tank, but it eventually goes wrong when the water company adds something extra. I know Byron and others get away with it and have done for years. They are either lucky or have a very good water company that is careful about what it adds. But most people eventually lose a tank of fish doing water changes and filling the tank directly with tap water.

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Have you ever heard of larger fish being more resistant to chlorine? What confused me most about the incident was that the Apistogrammas pair and bamboo shrimp survived. I thought the shrimp would be most sensitive to some sort of water fluctuation.

Most fish deaths associated with chlorine/ chloramine are from the fish being closer to the chlorinated water or being exposed to the chlorine/ chloramine for longer periods of time. The Apistogrammas and shrimp were probably at the bottom of the tank and maybe hiding in a cave or plants and this would slow the flow rate of chlorinated water around them. Thus giving them the ability to survive longer or suffer less damage.

Other fishes that were in mid water or near the surface might have swum into the current and copped a full dose of chlorinated water for several minutes. These would usually show symptoms and die first.

 

[I Like Rare Fish]

My water company does chlorine flushes, where there are 3x the amount of chlorine than they normally have. Watch out. You can look up the chlorine flushes online.