Have I Purchased Diseased Fish?

[Gillian]

Hi - I purchased 5 male guppies on Sunday and introduced them to my (fairly new - 3 months) tank. Monday morning, 1 had died and one was acting very strangely (staying near the very top of the tank and hardly moving). This one died shortly after. Tuesday, we lost a third. This morning we lost a fourth, but have also lost 2 of our blue harlequins.

25l water was changed on Saturday and gravel cleaned. All other fish appear healthy (at the moment). Water tested after water change - all at excellent levels.

Have we bought diseased fish (can't see any signs on dead fish).....what redress (if any) do we have with the well known pet store where they were purchased? (went there yesterday just to look at the tank where ours came from, and they all looked fine).

As you can tell, I'm quite new to this so any advice is very welcome before I lose the rest of my fish

Thanks in advance - more details below

Tank size: 125l
pH: 7.5
ammonia: lowest on scale
nitrite: lowest on scale
nitrate: lowest on scale
kH:
gH:
tank temp: about 78 F

Volume and Frequency of water changes: 25l changed Saturday. Previous 25l change was 2 weeks previous.

Chemical Additives or Media in your tank: Easybalance

Tank inhabitants: 3 loaches, 6 mollies (and 4 babies), 8 neon tetras, 6 (now 4) blue harlequins, 5 (now 1) male guppy

Recent additions to your tank (living or decoration): 5 male guppies

 

[Anna Robinson]

Hi Gillian

When you say your ammonia, nitrite and nitrate were 'lowest on scale', do you mean that the reading was zero, or that some was present, just at the lowest level?

 

[Gillian]

Hi Gillian

When you say your ammonia, nitrite and nitrate were 'lowest on scale', do you mean that the reading was zero, or that some was present, just at the lowest level?

Sorry to be ambiguous. I have individual testing kits. The nitrate and ammonia are zero and the lowest scale for the nitrite is <0.3.

 

[Anna Robinson]

If your water is good then it does make it more probable that there was a problem with the fish. However, I am a little suspicious of the readings, since it is incredibly unlikely that a tank would have a nitrate reading of zero.

Can you take some water into the shop and ask them to do a test for you? A good shop should really offer a water testing service if you've lost some of their fish. See what they say about it all.

In terms of what redress you have if there did turn out to be a problem with the fish, I think you would have to prove that they had been negligent with the fish in some way (at least, here in the UK anyway). The law recognises that health problems are an inherent risk with any live animal, and no one is necessarily at fault.

 

[Gillian]

Many thanks. Will go back to the shop with a sample of water.

 

[Athena]

So, on Saturday you did a water change and tested the water and levels were fine (apart from trace nitrite). Then on Sunday you added 5 guppies. After they died, did you test the water again? Have you done a water change since the deaths? If not, I would do at least a 25% change.

I suspect that putting 5 more fish in a tank that is already well stocked probably caused a nitrite/ammonia spike. If there was already a nitrite reading, however small, this could easily have been tipped further up the scale by adding the extra fish.

The reason I say your tank is already well stocked is that your tank is 33gallons and you had already over 42" of fish (approx as I don't know exact size of your loaches or what type they are but I allowed 2" for each and loaches are usually messy fish anyway, adding extra burden to the filter bacteria). Adding 5 more guppies would increase that by at least another 5" if the guppies were small.

Obviously, some tanks can run over-stocked with good quality over-filtration and regular tank maintenance. I'm not assuming yours isn't, but usually with sudden death of new fish like this it is because a) they suffer stress from the move b) stress from the different water conditions and not enough time to aclimatise to it c) because they are stressed they are more susceptible to any minor spike in toxic chemicals e.g. ammonia/nitrite.

Adding extra fish to a tank that is already well-stocked often means the current level of filter bacteria can't cope with converting the extra waste load.

I doubt the fish were diseased in the shop if they were (and others still are) swimming normally and behaving/looking healthy.


Regards - Athena

 

[Gillian]

That's very useful. Thanks. I have just re-tested this afternoon (using TetraTest kits)

Ammonia - zero

Nitrite - 0.3mg/l

Nitrate - between 5-10 ppm

Are these high enough levels to cause problems? Is this why occasionally fish stay on the surface of the water? Will do a water change today.

When we started the aquarium, we didn't have any problems even though for a small period of time ammonia and nitrite levels were quite high. We stocked it slowly as per advice from the shops and didn't think we had overstocked. All fish are still relatively small (mollies are the largest).

Our major concern this morning was that our established fish that we have had for some time now appear to be suffering.

As long as we can stop the deaths, this is main aim now.

Many thanks for your help and any further advice is appreciated.

 

[Davo86]

Your nitrite reading really should be 0,

Also with the current stocking i would be doing 25-30% water changes weekly as a minimum

 

[GSD]

My guess would be poor water quality, since the tank is failry new and wouldnt be able to cope with such a large amount of stocking at this stage. The guppys being at the surface also leads me to think this.

I agree that water changes should be weekly, 30% as you are overstocked.

 

[destinyxrose]

Definitely Weekly water changes at 30%. You really should consider investing in a larger tank especially if you are wanting to get more fish (If you get a larger tank be sure to cycle it before moving them). You really should have at least 1 gallon per inch of fish. Water stats may be higher but even if they aren't the over crowding can cause too much stress for them as well. If your other fish start showing other symptoms then there may have been a diseased passed over from the other fish but without any symptoms it sounds like just over crowding. Make sure that you do a water change if you haven't done one since the others have passed. Hope everything works out.

 

[Anna Robinson]

Yes, if you're definitely showing nitrite in the water then something's wrong. It looks like water quality is the issue here, as any nitrite level will cause some problems. These sort of things can cause the fishes to gasp at the surface, if that's what you're getting.

As the others have said, do lots of partial water changes while there's any sort of problem with the water, to dilute it out (maximum of 25-30% per day, though). Your shop can also provide you with additives to help remove the nitrite, such as nitrite-absorbing resins. Feed very sparingly, to avoid adding any more load on the filter, but don't stop all together, as that is too hard on the fish.

To be honest, your tank doesn't seem overstocked to me, but a lot depends on the filtration etc, and if you're reading nitrite then your filter isn't coping with the fishes' waste, so in that sense you are definitely overstocked. Do you have any idea why your filter might be struggling?

 

[Gillian]

Thanks for all your comments. We done a water change last night, and all is well this morning. The one surviving guppy looks fine as well. I am going to water test shortly (as soon as my baby allows me to put him down!)

It seems the stocking situation has sorted itself out by the fish we lost.

I have no idea why the filter may be causing problems. We have a Jewel Rio 125 system (see http/www.petcentreonline.co.uk/ecommerce...roduct~842.htm) which came complete with filter system. We change the filters as recommended. The top white filter is often changed twice a week. We feed the fish morning and evening. The evening feed also contains 3 little pellets for the loaches....although the mollies often can be seen fighting over it!

 

[Anna Robinson]

Glad to hear things look better


Your feeding regime sounds good, the only thing I would say is that you shouldn't really have to change the top white filter twice a week with the amount of fishes you have. (I assume if you don't change it, the flow slows down?). So you might be overfeeding a bit. Remember a small fish only needs about one flake a day (over at least two meals, though). All food added (apart from the loaches' pellets) should be gone in two minutes. If you can still see any of it drifting about after this time it was too much.

I like Juwel filters, they are much better than most internals. It's a good tank.