Mystery deaths? Help needed.

My tank is struggling at present and I cannot pinpoint what the problem is.
In the past few days,Ive lost 2 guppys,2 albino cory's and a kulhi loach,with another kulhi on the way out also I suspect.
Ive checked the readings and will need to re-test in a half hour as the readings were abit unusual.
PH 6.5 ish. (I always thought Id higher but its testing similar from the tap).
Ammonia 0
Nitrite 0
Nitrate 0 (I always have some level of nitrate reading,I'll retest it later,I suspect I wasnt shaking the bottle enough but none the less the reading showed 0 when I did the test earlier!).

So Ive no ideal why my fish are dying,other fish are behaving normal and it appears to come on suddenly as all other fish are moving around nicely and indeed even my L144 has spawned again so Ive no idea what is happening here.
I do regular 15% or so water changes,tank is established a few years,Ive added some new fish over the past week alright,dwarf gourami x 2 (both seem fine),guppys who died (I suspect from fin nipping),and I added the Corys also (2 of the 3 died).
Id of said it was something to do with the fish if it was confined to the fish I put in,but the rummy and the kulhi's are in the tank for ages so Ive no idea what is happening here.
Anyone able to help please,I dont wanna lose any more fish at this stage.
The fish that died didnt have any physical markings on them,nor were they behaving strange,they just seemed to slip away without as much as a whimper. I dont have a test kit for iron etc,so Im wondering would it be anything like that,but my shrimp seem to be alright.

Ive done a 30/40% water change now.

All help much appreciated

Gavin

Had thought of that alright John,but I did a water change Thursday of last week.
So really its like 8 or 9 days on that the problems have started happening so I suspect the water was ok.
The council have certainly killed many a fishkeepers fish over the years by adding chemicals etc without warning but on this occassion I dont think that was the issue,esp when it was over a week since last water change.

Gavin

What's the water temperature?

25c or so. Temp is fine.

Just a thought.

If I have read your post right, you added 3 corys, two died, you added guppies and they died. When did you add the new fish?

Guppies are unlikely to die suddenly from fin nipping, unless they were nipped to shreds, which I am sure you would have noticed.

I would be inclined to point the finger at the new fish - so where does that leave you now? Keep up with the extra water changes and re-test carefully those readings can't be right, is the test kit out of date?

Look for signs of any problems with the remaining new fish particularly, no point treating the tank until you know what you are treating.

Lower the temp a little, if it is at 25C drop to 23 or 24, it might slow the spread of whatever it is.

Do you use water conditioner, which one?


Daragh

JohnH wrote:

Gavin,
If everything was OK until recently it might well be due to something in your water/stock having changed - I realise you have added new fish (always a point of suspicion) but how about anything else?
Please re-test the pH of the water in the tank (although that won't be conclusive as you have [quite rightly] done a large water change) in case of a pH crash.

Have the water company done anything to the water supply recently? - It isn't unheard of that they flush pipe through after working on them without notifying anyone and what they use isn't always conducive to the best health of our fish.

Any other suggestions?

John

this happened me i was rightly F'ed off about it, the tap water had a manky taste of it, i was gonna head up 2 the water treatment department and crack some skull. and mind you it been a bit off of late

Daragh_Owens wrote:

If I have read your post right, you added 3 corys, two died, you added guppies and they died. When did you add the new fish?

Guppies are unlikely to die suddenly from fin nipping, unless they were nipped to shreds, which I am sure you would have noticed.

I would be inclined to point the finger at the new fish - so where does that leave you now? Keep up with the extra water changes and re-test carefully those readings can't be right, is the test kit out of date?
Look for signs of any problems with the remaining new fish particularly, no point treating the tank until you know what you are treating.
Lower the temp a little, if it is at 25C drop to 23 or 24, it might slow the spread of whatever it is.
Do you use water conditioner, which one?

Daragh

I think the guppies probably were bullied so Im not too worried about them,the dwarf gourami and rams would of probably started on them. I was away last night so wouldnt of spotted it in time if it was a bad case of nipping and more.
The new fish maybe,ie.the gourami's but then again I dont the Kulhi loach would of fallen to the gourami,there are alot of hiding places for the Kulhi's to get to and as a result would of been almost impossible for the gourami or any other fish to catch the Kulhi's.
The test kit is brand new and in date. The water conditioner I use is API.
I retested the Nitrate,and it tested about 10mg/l. Does'nt seem too out of the ordinary.
So I guess its a case of keeping a close eye on things now and wait and see?

Gavin

Think this was flagged ages ago. New fish introduced, problem appears. All params the same. Who you gonna blame?

looks to me like the new fish might be carrying something! maybe you could use some broad based cures in advance to head off trouble. i think the ph is too low for guppies.
phil

Havent any issues before with guppies in my tanks,I still think they just got a battering.Its the Kulhi's Im most annoyed about. Also given they are bottom feeders,perhaps its the substrate sand realeasing gas'es etc. Ive given it a stir,have added fresh carbon to the filter and will keep a close eye,as Id another Kulhi gone this morning (I think it was the one that was on the way out y/day).
Weird thing is that the fish are behaving normal still.
Will keep up the water changes now and hope for the best.
Gavin

Did you get a smell when you stirred up the substrate? If there was anything bad there you should have got a nasty whiff of it as it was released.

I don't keep carbon in the filter, I only use it as needed, yet I find a lot of people leave it in. Which is the way to go with carbon? in when needed or always?

As this setup is going a while I take it you have been keeping up on the gravel, years you said, so if you hadn't the tank would be rank when you disturbed it and would have had sick loaches for sure before now.

New arrivals or water supply are your problem unless you have added any ornaments plants or otherwise?
What state is your filter media in? In case the deaths and arrivals are just a coincidence.

I'd fill a bucket from the tap and ph test it, leave it 6 hours and test it again, see if there's a change in ph.

The ablinos had no marks, no red on the underbelly or between the gills and fins on the flanks, pinkreddish even?


Mark

I use carbon only when needed. I dont leave it in normally unless removing meds or on occasions like this.
There was no smell from the sand substrate,its stirred regularly enough although the back of the tank wouldnt always get done but it gets done enough to prevent build up of gas etc in my opinion.

The new arrivals I think are the problem.The last water change prior to the deaths were 7 days so it was a sudden kill off which would suggest the new arrivals may of bought something in on them.
There was reddish marks one of the albino cory's but it died the night I got it,I suspect it got battered in the bag on the way home.
No new plants and ornaments added lately,I got rid of some plants that I wasnt sure about but they werent the problem as they have been there for years also.(and are fresh enough,no real dead leaves etc).Ive knocked the temp down a notch also to 23c.
Ive done the tap tests and they appears to be fine and in line with the PH of the tank also. Filter media was dirty enough alright today,I cleaned the filter out and replaced some filter floss when putting the carbon in. Hopefully the tank will get back on track now,I'll keep the water changes up this week. I suspect it was the new fish bought something in,having said that,Ive another albino that went into the other tank and its perfect(was going to isolate it but its showing no signs etc).
I suppose the lesson to be learned is QT all new additions but I think we have all been guilty of not doing this on occasions,plus Ive the QT tank being used at present for another 2 corys for the past 6 months!

I'll just keep an eye on the tank,on the plus side,the L144 is still guarding the eggs and I think they will hatch pretty soon,Im going to try and get a few of them out into another tank this time around.
Gavin

Just wondering……..what state were the fins of the Corydoras? Ragged? Any worms-like things visible?

But, in general, not always easy to tell why a tank wipe-out occurs without being at the location. Lots of guesses, and lots of negatives on the guess list.

Water chemistry….often it only the easy-to-test water chemistry moieties that are tested and cited. These are not always the answer, but may have some hints.

If the test kits are correct, and the nitrogenous levels quoted are real then that seems fine.

BUT…I was very interested to see that the initial nitrate level AND nitrite AND ammonia were cited as zero. Rather unusual for water that’s been lived in.

But, ammonia poisoning cannot be ruled out even if the water test says zero.

Bulk-Phase (in the water) Ammonia poisoning is pH dependant…….but you can still get pH dependant ammonia poisoning even when there is zero detected in the water: the water pH may be such that ammonia does not disperse from the fishes gills.

But, do I suspect ammonia poisoning? No. But….never rule out if symptoms of ammonia poisoning are observed.
Different fish have differing brain chemistry to deal with ammonia, and as a range of fish have been lost then only a high water ammonia or extreme of pH would wipe-out a wide range of fish species from ammonia poisoning.

pH…..this can swing very rapidly if the buffering capacity is low.
If you have very low ammonia in an established tank, then that would indicate that nitrosofying bacteria action is pretty good.
That action will deplete oxygen, but will also produce nitrous acid.
The nitrous acid can drop pH in a poorly buffered tank.

Then if that is not a problem, then the next stage (nitrification) will remove nitrite and produce nitric acid (of which the salts are nitrates) and deplete oxygen. Nitric acid is a strong acid, and will potentially drastically drop pH in a poorly buffered system.

Introduction of more fish can push the filtration system into a product overload that can reduce pH quite dramatically and maybe only transiently.

And upset pH can produce ammonia poisoning by virtue of altering excretion of ammonia.

What else might be on a check-list for wipe-outs?

There could be some chemical in the tap water for which you don’t have a test kit…... That’s a maybe, and would not be my first port of call. But, of course, can never be ruled out.

On that, I’d always recommend using a good chelating agent such as tetra aqua-safe anyway (and it helps reduce stress anyway)


Chemicals introduced with new fish?
Maybe. But what?
Some medications may affect some fish even in residual amounts (there are a few examples of specific fish being extra sensitive to certain medication), but there is a range of fish died….and so I would not place any blame on that in this case.

Losses to newly introduced fish is quite common especially if fish have come from disease-free very clean water.

Dead fish (new or old) lodged behind filters or bogwood might be a cause…..not sure if this has been the case.
It doesn’t take long for toxic compounds to leach from a dead fish.

Food….uneaten food lodged, or hanging around for an hour or two before eaten. Fungus on food can produce compounds that will rapidly kill fish that eat the contaminated food.
Maybe the new introductions have upset the system, and caused food to hang around uneaten for an extended time.

Anaerobic gas products? But that would mean coincidental with new introductions.

And there is more…..depending on how each item on the list is ticked-off.

Ian