• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Fish Deaths?

Brian Murphy

Member
Joined
20 Oct 2012
Messages
592
Location
Omagh, N.Ireland
Over the past 2 weeks I have had fish dying on me and not showing any signs of illness until I see them dead the next day. It is a Hi-tech tank with Co2 injection but I have ruled that out as the fish would show stress if they where getting too much. I did run out of Co2 at the start of December and with one thing after another during the month I never replaced the Co2 or done a water change for about a month and it was just after doing the water change that they started dying off. I bought 4 SAE to clean up some BBA and 3 died within 2 days before the water change and so I decided to do the 50% water change and start the Co2 again but ever since then plus one more weekly water change neons mainly plus some ottocinclus and 2 denison barbs have died. Some days I would find 5 or more neons dead and then days when none would die. It is just random and I get no indication that they are ill. Here are my theories but if anyone else might know please advise.

1. Water parameters have changed i.e. water from tap has added extras over the xmas period
2. The 4 SAE had a disease and infected the rest (although one of the SAE is still alive after 2 weeks)
3. One of the Denison barbs is attacking the smaller fish (no visible bite marks)
4. Dodgy Co2 gas or contaminated gas?
 
Hi all,
Water parameters have changed i.e. water from tap has added extras over the xmas period
Definitely could be, if you have water main work locally? it is very likely that your water has an <"emergency dose"> of chloramine. I'd definitely use another water source for the while, it is one of the reasons that I use rain-water.
t is a Hi-tech tank with Co2 injection but I have ruled that out as the fish would show stress if they where getting too much
I don't think your gas will be contaminated, but CO2 poisoning is a possibility if you have water where the oxygen demand is now higher (for example if chloramine had been added).

The reason for this is that the rate of diffusion of oxygen through the gill cell wall is dependent upon the differential between the level of dissolved oxygen in the blood and tank water. If the level of dissolved oxygen in the tank water is lower than normal it takes longer for the oxygen to diffuse in and be picked up by the haemoglobin in the blood. The same haemoglobin molecules also transports CO2.

There is more discussion <"here"> in the <"Bohr-Root effect"> link.

cheers Darrel
 
not an expert but you added some fish? then the deaths started within a few days? if it was me i would be looking at the filter bacteria not adjusting to the load then once fish start dying the over load on the bacteria keeps climbing just a thought im sure the experts will help you with good advice :) but if it was me i would step up water changes and add extra amounts of prime
 
Hi all,
not an expert but you added some fish? then the deaths started within a few days? if it was me i would be looking at the filter bacteria not adjusting to the load then once fish start dying the over load on the bacteria keeps climbing just a thought im sure the experts will help you with good advice :) but if it was me i would step up water changes and add extra amounts of prime
That is a definite possibility, more fish would have the same effect as chloramine dosing, a continual extra trickle of ammonia. How damaging this would be would probably depend upon how heavily planted the tank was.

If I was going to carry on using tap water (which I'd avoid if there was any alternative) I'd definitely use Alllan's suggestion of "Prime", or "Amquel" as a water conditioner.

cheers Darrel
 
I also doubt 4 extra SAE's would trouble the bio load that much.

The 3 SAE's died even before the water change if I've read it correctly, which would rule out chloramine in the water. Add in the fact you're treating the new water anyway and that's that theory gone really.

If it was just the SAE's dying you could obviously put it down to some disease they have, but do you think if they had got something it could spread and kill the others so quickly?

I wouldn't rule the Co2 either. Maybe even turn it off for a week or so, just to rule it out altogether. The natural symptom of Co2 overdose as you know is gasping at the surface. I was working away a few weeks ago when my Mrs rang me to say the fish were laying on their side on the bottom, not a classic symptom but it ended up being down to the Co2 anyway. No one was around to actually witness any gasping, so just caught them just in time :nailbiting:
 
The fish mentioned would not normally be described as difficult or delicate ,hotfoot back to the dealer were you got the fish and ask the questions ,its either started at source ie the new fish or you had a existing problem that was about to happen,The fact one fish your SAE got through it is often the case.I had similar with some Cardinals once I think stressed after the home trip back a few died the day after ,I used E-Sha and still have some now about 6 years old.You need to sort it ASAP so take a small jar of aquarium water(Maidenhead stores are good)have your water paramiters tested. Good luck
 
So I contacted Northern Ireland water and requested information from them regarding any treatment they may have done and this was the response ..............


Thank you for your email of 25 January 2015, in which you asked whether the
disinfectant arrangements for your water supply zone had recently been altered.
As your query falls under the definition of an environmental request, NI Water is
replying under the Environmental Information Regulations 2004.
There was no real change during the period you specified (December to January).
During December the mean level was 0.70mg/l, with the January mean thus far being
0.74mg/l.
NI Water does not use chloramine as a disinfectant at any of its Water Treatment
Works. Our current disinfection policy is to use Sodium Hypochlorite.
During and after mains rehabilitation in a particular area, there will be fluctuations in
chlorine residuals within the distribution system. Whilst the chlorine levels may be
slightly above normal for a short period, thereby ensuring bacteriological quality is
maintained, there are no associated health risks for human consumption.
However, fish are more sensitive to minor changes in water quality and we
understand fish keepers/aquarists advise that water should be de-chlorinated (dechlorination
chemicals are available in aquatic shops) and conditioned (left standing
in a container for 24 hours) and that this procedure would usually ensure the wellbeing
of the fish. It is also good practice that a maximum of 10-20% of water in a tank
is replaced at any one time.
 
Back
Top