Sometimes when you use prime you can actually overdose as they will suck the oxygen out of the water column within two hours of dosing it is not instant. Congos in my experience is very finicky with lack of oxygen in the water.
Water Change followed by Dead Fish
- Thread starter The Masked Shadow
- Start date
I dosed about 3/4 of a capful. 55G tank. It also has a sponge filter and TopFin75 HOB
I'm pretty sure 5mL of Prime is enough for a 55g.
you should always know your tap water parameters. You can check on government web sites. To be safe, you can test the tap water you are using to find any problems.
Do you do a simple test of water temperature change? It's easy enough to do, put your hand in the tank water, and then put your hand in the water that you are filling up with. It's easy enough to feel the difference.
When was the last time you did an 80-90% water change. Having done this myself many times, it's not an issue. But my water reservoir is different from yours, even though we both have really hard water with PH 7.8-8.2.
There are a few possible things:
1) Your area sometimes does a chlorine flush, where the disinfectant is doubled in the water. The easy fix is to double your Prime dosage to 2 capfuls, putting half in the beginning and the other half near the end.
2) The oxygen level was low, hence why your bichir was not affected, why your congo was a little doozy, and why you didn't see a problem after 2 hours. Some fish just have a higher need for oxygen levels than others.
3) Your bichir took a shot at the congos a few times, and they slammed into the sides of the aquarium real hard. Not unusual for a fish to die of hitting the sides of the aquarium. That could also explain the dooziness of the last congo.
I doubt it's PH shock, so many plant keepers inject CO2, and then turn it off, allowing the PH to stabilize at normal levels within a couple of hours, so a jump from a PH of 6.5 to 8.0 is not uncommon for them. Also, the KH for your water is pretty high so any shift would be less than 0.3, which is not enough to affect fish.
When was the last time you did an 80-90% water change. Having done this myself many times, it's not an issue. But my water reservoir is different from yours, even though we both have really hard water with PH 7.8-8.2.
There are a few possible things:
1) Your area sometimes does a chlorine flush, where the disinfectant is doubled in the water. The easy fix is to double your Prime dosage to 2 capfuls, putting half in the beginning and the other half near the end.
2) The oxygen level was low, hence why your bichir was not affected, why your congo was a little doozy, and why you didn't see a problem after 2 hours. Some fish just have a higher need for oxygen levels than others.
3) Your bichir took a shot at the congos a few times, and they slammed into the sides of the aquarium real hard. Not unusual for a fish to die of hitting the sides of the aquarium. That could also explain the dooziness of the last congo.
I doubt it's PH shock, so many plant keepers inject CO2, and then turn it off, allowing the PH to stabilize at normal levels within a couple of hours, so a jump from a PH of 6.5 to 8.0 is not uncommon for them. Also, the KH for your water is pretty high so any shift would be less than 0.3, which is not enough to affect fish.
IMO this was most likely caused by one of the scenarios that
Rocksor
posted.
I will add this, some municipalities not only do large flushes during periods of high turbidity caused from storms etc, some also switch back & forth between chlorine, and chloramine treatment, sometimes with water pulled from different sources. It's a good idea for everyone to become intimately familiar with their tap water, especially if the tank is not well established. I have been doing massive water changes in my tanks for more years than I can recall, weekly 80-90%, but I also know both my fish, and local water supply, very well. It's not for everyone, for sure.
As far as a sudden shift in pH, from a past discussion ....
Generally when moving fish from one pH value to another, it's the sudden change in total dissolved solids (TDS) that causes issues such as osmotic shock, not the shift in pH. Going from high TDS values to low TDS values is far more stressful on most fish, vs going from low to high.
So for some fish, especially newly imported wild caught specimens, a sudden change in water values can become a double whammy. Initial stress from a sudden change in TDS that triggers osmotic stress, followed by an onslaught of bacteria that are not typically found in their native habitat.
Rocksor
posted. I will add this, some municipalities not only do large flushes during periods of high turbidity caused from storms etc, some also switch back & forth between chlorine, and chloramine treatment, sometimes with water pulled from different sources. It's a good idea for everyone to become intimately familiar with their tap water, especially if the tank is not well established. I have been doing massive water changes in my tanks for more years than I can recall, weekly 80-90%, but I also know both my fish, and local water supply, very well. It's not for everyone, for sure.
As far as a sudden shift in pH, from a past discussion ....
Generally when moving fish from one pH value to another, it's the sudden change in total dissolved solids (TDS) that causes issues such as osmotic shock, not the shift in pH. Going from high TDS values to low TDS values is far more stressful on most fish, vs going from low to high.
So for some fish, especially newly imported wild caught specimens, a sudden change in water values can become a double whammy. Initial stress from a sudden change in TDS that triggers osmotic stress, followed by an onslaught of bacteria that are not typically found in their native habitat.
I do a temperature check with a thermometer beforehand. The oxygen level was low for only 10 minutes or so, then both filters were running. The 3rd option could be, but I’ve never seen him actually take a shot at the Congo tetras, or show any care to them, though he has eaten fish before. Ill check my government site for the chlorine flush. Also, the Congo’s have been in the water for almost a year.
Fish don't act the same when a person is around. They are generally waiting for food from you (or think you are a possible predator). There's been more times of me finding predatory behavior later than in person. I think you've mentioned finding your previous Congos that have jumped before, so something is causing them to get spooked.
You probably won't find anything about chlorine flush or sudden switch to it from chloramine via the water authority's website. All you will find is the average level of disinfectant and other water values measured. It's best to know someone who works there. I know of some folks who have noticed this happening in your general area from time to time. Generally, doubling of Prime prevents the issue from coming back or narrowing down the issue to something else.
It depends how much the temperature drops in the tank. I use cold water a lot too, but I don't let the tank temperature drop more than 5 degrees, even for fish that do well in 68F temperature.
