my fish are dying!

[jsa500]

Now before you assume I'm another newbie who has obviously not let his tank mature properly or stocked it too fast, I'm not

The 20 U.S gallon tank has been setup for years. A few days ago I decided to add 12 more black neons since I only had 4 in the tank. Anyway everything is fine then a couple of days later I get up one morning and find a dead neon on the bottom of the tank. I removed the dead fish straight away and tested for ammonia, nitrite and nitrate. They were all 0, which wasn't surprising since the tank is quite densly planted so the capacity for biological filtration is big. I tested the Ph to make sure it hadn't crashed cause the water is quite soft. It was 7.8 as usual.

I decided that perhaps it was just one dodgy fish but the next morning, same thing again. And this has been going on for about 4 days now. I never see them die, I just find them dead. Black neons are the only thing in the tank so it can't be another fish killing them.

I've come to the conclusion that the fish I bought had some kind of super disease but I don't really know that much about fish diseases. I'd be grateful if anyone could advise what to do next

Thanks,

James

 

[Angry_Platy]

Welcome to TFF

The most likely explanation, assuming your other neons have been healthy prior to this, is that they have bought a disease into the tank....I am also asusming that you don't know whether it is the new or the old fish dying or both....they all look the same I guess....

Are there any unusual marks on the fish when you find them dead?

One possibility is neon tetra disease....once this gets into your tank it will kill all small tetra species....other fish will be fine....the only way or eradicating it from the tnak is to dismantle the tank and basically start again

I would go to your LFS and ask if they have had any problems with the other fish from the tank where your black neons came from....

HTH

 

[jsa500]

Hi Chooklet,
Thankyou for taking the time to reply to my post.

I can say with certainty that at least 1 of the original 4 fishes that were already in the tank is now dead. I can tell the difference since the new 12 from the fish shop are a bit smaller.

Symptoms

They seem darker in color than usual. Heavy breathing and hanging near the water surface. But from what I've read about fish diseases so far, these symptoms seem common to a lot of diseases.

 

[reg2k2]

tank is quite densly planted

Heavy breathing and hanging near the water surface

Lack of oxygen??
At night, plants reverse their respiration process---take in O2, let off CO2.
With the addition of 12fish, I imagine it could have an impact. Try adding an airstone or two.

 

[Tempestuousfury]

Gasping for air. If the tank is heavily planted, than an airstone or two might help when the plants respire.

Tips for next time:
Quarantine the fish first
Buy only a handful of fish at a time

to the forum. Introduce yourself in the newbie section.

 

[jsa500]

Hi,
Good thinking but aswell as the spraybar return i've also got a big external air pump. I tested the oxygen yesterday morning it was in between 5 and 8 mg/l.

Found another one dead this morning

Took a pic, have a look maybe you can spot something. I'm useless when it comes to diagnosing fish

Dead Neon

 

[Angry_Platy]

It looks normal to me....did you check the LFS where they new ones came from for any unexplained deaths in their neon tanks?

An airstone won't help the aeration in the tank...what you need is water surface disturbance..i.e. lots of current....that helps oxygen dissolve into the water...

 

[reg2k2]

An airstone won't help the aeration in the tank

sure they do...the bubbles *do* break the surface...

from the pic, i see his mouth is not open...so I guess lack of O2 is out..and of course, that you've a normal reading.
Yes, do check w/ the lfs...may be a quick answer...and you could be due a replacemt...

What is the pH in the morning?...and at 'lights out'?

 

[jsa500]

They are still dropping like flies.

I've actually seen a couple of them die now. They were very disorientated, swimming upside down and in circles. Looked a bit like something the red arrows would do.

Can we now say that this is a swim bladder infection?

I'll post the morning Ph later.

 

[reg2k2]

I think swim-bladder would show in more of a buoyancy issue...unable to swim up, or down, maybe listing to the side (I think).

I have seen something similar before tho. Some yrs ago, I lost maybe 6-7tetras and 2small cichlids...most of these I found on the filter intake. But on one occasion, I came home to find one of the tetras doing loopdy-loops, and expiring soon after. I now attribute these deaths to pH fluctuations.

I'm not a plant-person, but I suspect there may be something going on betw. your CO2 & pH. My experience w/ KH is in relation to a crash, but apparently in a planted tank, low KH can give way to rapid *rise* in pH... see 'what affects pH'

If this is the case, your morning reading sh. be quite a bit lower.

 

[jams.alaskan]

The new neons may not have been used to the small up and down of ph in the planted tank. That may explain some of the stress on them. It does not explain why you lost one of the older ones however. The photo that you provided doesn't give me any clues as it looks to be a fine fish and there is no real damage or change to it. I hope that this is sorted for you soon. would really suggest that you quarentine any new additions next time as we really don't know what is causing this. Neons of today are less hardy then they were some years ago but I do not know that the same is true for the black neons.

ALASKA