Newly Acquired Fish Dying

[mark4785]

This weekend I purchased 5 Black Neon Tetras for a fully cycled open-top aquarium. Before going to purchase the fish I double checked that the ammonia, nitrite, PH and nitrate levels and temperature were all at suitable levels and they were all within range, as can be seen below:

Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 15 ppm
PH: 7.2
Temperature: 27 degrees C

I introduced the fish to the aquarium at 2:30pm and by 7:00pm, two of them had died and the rest were gasping for oxygen at the water surface. I didn't think that I had any sufficient reason to check the water o2 levels since the water's surface is rippling quite a bit allowing oxygen to enter the water column. In addition, although this aquarium will be a planted tank at some point in the future, there is no co2 injection at this point so this couldn't be the source of low oxygen diffusion. At 7:30pm I checked the o2 levels using a basic test kit and got a o2 reading of between 1-2 mg/l. In contrast, my established planted aquarium had a o2 reading of 8 mg/l.

I am really confused and upset that I've lost two of these fish and would therefore appreciate it if anybody has any explanation as to why oxygen levels in this newly cycled aquarium are horrendously low.

Note: the remaining 3 black neon tetras have been transferred to my planted aquarium and are not gasping/dying.

 

[WILDER]

How long did you climatize the new fish for?
Always check bag water for temp & PH.
What is the brand name of the test kit you are using?
How many gallons is your tank?
How many fish and which type.


Did the fish also start to dart around the tank?
Turn upside down?
Do the fish look pale?

Sorry for your loss.

 

[mark4785]

How long did you climatize the new fish for?
Always check bag water for temp & PH.
What is the brand name of the test kit you are using?
How many gallons is your tank?
How many fish and which type.


Did the fish also start to dart around the tank?
Turn upside down?
Do the fish look pale?

Sorry for your loss.

Hey,

They were acclimatised for approximately 30 minutes. I floated the bag of water that they were supplied in for this period and added a small amount of aquarium water to the bag every 5 minutes. The temperature of the water in the aquarium and the bag matched exactly.
I used the o2 test by Tetra
There is 120 litres of water in the aquarium
5 Black Neon Tetras
They were not darting at all; they were initially swimming around the aquarium without the gasping symptoms.
The 2 that died turned upside down followed by death less than a minute later.
The horizontal black line on the fish went a pale colour

 

[WILDER]

The problem with open tank tops is that house hold chemicals can enter the water.
Also fish can jump out.
Have you been using any household sprays near the tank. Or air fresher.

 

[mark4785]

The problem with open tank tops is that house hold chemicals can enter the water.
Also fish can jump out.
Have you been using any household sprays near the tank. Or air fresher.

No, no aerosols have been used near the aquarium by any person in my family as we all know that the gases they give off shouldn't be used anywhere near fish.

 

[WILDER]

OK. Just needed to rule the possibility out.

Do any of the remaining fish show any of these symptoms.

Pale in colour, or darker in colour?
Any grey, or white film on the fish body, fins?
Any excess mucas on gills, body, fins?
Do the gills look pale, red and inflamed, purple gills?
Any signs of flicking and rubbing on objects in the tank?
Do any of the fish crash to the bottom of tank?
Can all fish maintain there balance in the water?

PH Shock Symptoms.

Lying on the bottom and paying little or no attention to its surroundings and ignoring potential threats.
It may even lay on its side or go upside down completely. There could be other signs to, related to Acidosis and Alkalosis.
Excessive mucus production.
Rapid breathing.
Swollen abdomen.

http/groups.msn.com/FishHealth/phshock.msnw<br

 

[mark4785]

OK. Just need to ruled out.

Do any of the remaining fish show any of these symptoms.

Pale in colour, or darker in colour?
Any grey, or white film on the fish body, fins?
Any excess mucas on gills, body, fins?
Do the gills look pale, red and inflamed, purple gills?
Any signs of flicking and rubbing on objects in the tank?
Do any of the fish crash to the bottom of tank?
Can all fish maintain there balance in the water?

All of them are their usual colour. Bold black line horizontal line and normal white/grey outer body.
No
No
No
No, swimming in a shoal as normal (they have joined the other black neons I have in my established aquarium)
No
Yes

 

[WILDER]

OK.

Just keep a close eye on the remaining black neons tetras.

The only thing I can think of is PH shock. Or temp.
I would of expected the remaining fish to be showing signs of PH shock.
The only other thing I can think of is the fish were stressed.

I would maybe do a 50% water change on 120 litre tank.
Check your water stats again.

 

[mark4785]

OK.

Just keep a close eye on the remaining black neons tetras.

The only thing I can think of is PH shock. Or temp.
I would of expected the remaining fish to be showing signs of PH shock.
The only other thing I can think of is the fish were stressed.

As soon as the 3 remaining fish (from the new open-top aquarium) were transferred to my established aquarium, they continued to gasp for approximately 1 minute and then they swam towards the concurrent shoal and all gasping stopped. So, if this rapid breathing was caused by PH shock (I personally think the 1/2 mg/L of oxygen in the open-top aquarium caused them to die from suffocation) all symptoms have disappeared now.

As mentioned, the open-top aquarium was fully cycled and I did a 100% water change, replacing the water with fresh dechlorinated tap water prior to introducing the fish to the tank.

I have been using bicarbonate of soda in the open-top aquarium during the cycling period which increases the water PH. It may be that there is residues of this in the sand. If there was a substantial residue I'm sure the PH would be much higher than 7.2.

 

[WILDER]

Give the sand a good vac.
I would let them settle down for a week before moving them again.
If any more problems don't hesitate getting back to your thread.


Sorry for your losses.

Good Luck.

 

[mark4785]

Give the sand a good vac.
I would let them settle down for a week before moving them again.
If any more problems don't hesitate getting back to your thread.


Sorry for your losses.

Good Luck.

Thanks for your help. i'll vac the sand and do another 100% W/C in the days before I plan to add anymore fish. I'll fill a little beaker with sand and water afterwards and take it's PH as well to see if there is bicarbonate of soda leaching out between the sand particles.

I don't know what to do about the oxygen problem. Any ideas?

 

[WILDER]

Sounds good to me.
If the water surface rippling it sounds fine. But you could always run airstone.
Is your filter running at full flow?

 

[mark4785]

Sounds good to me.
If the water surface rippling it sounds fine. But you could always run airstone.
Is your filter running at full flow?

The filter turnover rate is 1400 LPH I think. It is always running at this rate because you can't adjust it.

An air stone will definitely help, and I can run one, but this is only a temporary solution. The tank is very capable of having oxygen in it given the large amount of surface rippling and turnover rate. That's why its tragic to find that the water barely has any o2 and was probably part of the reason why the fish have died. I perhaps need to clean the filter sponges as there could be a lot of friendly bacteria in there using up all of the oxygen.

 

[WILDER]

I would maybe start a thread in tropical discussion about your oxygen levels being so low.
Also don't forget to mention the bicarbonate of soda.

I do think it's something to do with your tank water. Once you added them to your other tank they were fine in 1 minute.

 

[WILDER]

Some information for you.

Oxygen Deficiency

Symptoms:

Fishes that suffer from oxygen deficiency exhibit increased breathing, restlessness, and hanging under the surface of the water, gasping. Oxygen deprived fish usually have an overall pale coloration. Fish that die from the condition are usually observed to have their mouth open, in addition to exhibiting pale skin and gills.


Cause:

Lack of oxygen. This could be due to one or several factors: overcrowding, heavy feeding, dirty filters, poor aeration, a small water-to-air surface area, polluted water, elevated nitrite levels, and excessive algae growth or too many live plants. This last factor may not seem a logical one, but in the dark, plants and algae actually take oxygen out of the water, giving off carbon dioxide just as the fish do. Only in the presence of light do they release oxygen. Consequently, if you find your fish gasping at the surface in the morning, you may find you have too many live plants or too much algae in your aquarium.


Treatment:

Perform an immediate water change and increase the aeration in your tank. There are several methods for increaseing the water movement in your tank. This is important to ensure that your fish are getting the oxygen they need to stay healthy.


fish-disease.net