Losing Cardinals ?

[darrell]

This one has got me. A little background. I have been fishkeeping for about eight years. Currently have a 24x24 tank which has been running for about seven weeks. I have a dennerle co2 system with undergravel heating cable and I would say pretty rampant plant growth even after this small amount of time.

After two weeks I stocked with six X-ray tetra which have been fine so far. At the moment ammonia=0.1 nitrites=0 nitrates=10 and PH is about 7.8 Which to me seems pretty good.

Saturday I bought 10 Cardinals, then the problems started, one by one they started hanging and bobbing and then getting really lethargic in the water, rapid breathing, ultimately their bellies turning white as cardinals lose colour when they are dying. So far I have lost nine. On closer examination it seems as though their tails have disintegrated some leaving just a stump. But the one which remains is vibrant in full colour and seems ok. Obviously water quality was my first thought but as it stated it looks o.k. Could this be disease. Should I return to the shop? Thanks for any answers.

[stormhawk]

The pH at 7.8 is way too high for cardinals. They come from acid waters and do not like to be kept at pH higher than 7 at the max.

Going by your description of the disintegration of the tail until a stump, I'd say they were hit by fin rot too. This may be bacterial in origin and your high pH may have contributed somewhat to multiplying the effects of the disease.

[darrell]

Thanks Stormhawk ever so much for the reply. Verry good food for thought.

I think it could be a combination of things, the local hard London water can be as high as 8.5 around here so I would be surprised if most of the shops didn't keep all of their fish in that PH region captive bred, except that they may have used RO of course. Obviously my PH has dropped in view of my Co2 input. My thoughts also are that there may have been an underlying disease that the hard water accelerated.

My concern now is for the one remaining cardinal which strangely looks vibrant and is eating and seems happy as larry. I should attempt to find retailerr that may keep captive bred cardinals in relatively hard water.

[stormhawk]

Hi Darrell,

Going by the looks of it, if your tap water came from underground water sources or is from an area rich in minerals, it comes as no surprise that the water is hard.

Before you go out and purchase any more cardinals, like you said, do check beforehand as to whether they've acclimatised their fish to hard water. Most likely they used RO water mixed with regular tap water just for some blackwater species.

A sudden osmotic shock (due to the vastly different water parameters) may cause major distress to their gills and may kill them. If you do get anymore cardinals soon, rig up a length of air tubing with a control valve at the end and then do the drip method using water from the tank that they're going into. By doing so you slowly acclimatise them to the tank water without stressing them too much. Unless you know the shop's water quality is just about the same as yours at home, always do the drip method to prevent casualties.

Best of luck to any future cardinal purchases.

[celticfish]

fishes from the acidic blackwaters of the amazon have zero immunity to certain bacteria that thrive in the higher PH values. so they need the low PH values that effectively prevent these bacteria from thriving. i have killed many of my green neon tetras till i did some research.... *sigh*

but the newer fishes and whats left of my lot of fifty green neons (eight now..) are reaping the rewards of the previous deaths!

you may want to try black peat moss. i believe there are granulated ones from SERA etc. it should bring your PH down without having to invest in a RO filter. i just put mine wholesale into the tank in a nylon stocking. some put in into cannister filters too.

we have some local tropical trees that have acidic leaves. i add these direct into my tanks too. unsightly though. it will stain the water colour to a yellowish tinge. from where you are, i am assuming london, england, you can try beech tree leaves. you may want to check with your local fish store about this. got this information from cryptocorne growers who use beech tree soil becuase of its acidity.

blackwater extract helps too if you cant do the above.

[Danielone]

Hi all,

Just noticed a similar problem with my cardinals yesterday. I saw one fish that had NO TAIL!, just a stump left of it's tail. It was struggling to stay upright. I then looked carefully at the rest of the cardinals and noticed 2 or 3 of them have white dots / bobs at the caduncle (pardon my wrong spelling). The rest of the body is clear/normal, just the tail portion. And 1 of them actually looked like something bit off a portion of the tail.

What's wrong with them or wat's happening to them? I initially suspected the my shrimps or other larger fishes took a bite at my resting cardinal, but then with the white dots/bobs, I'm beginning to suspect some disease/illness. Am I correct?

This tank has been established for about 3 years already without any problems/illness. Other fauna inside: rummy nose tetra, black neons, assorted cories, otos, yamatos, and 1 wood shrimp.

One change I did recently was to inject CO2 to fight off a bad BBA attack. Previously before the BBA, I did use DIY CO2 for a short while, discontinued for about 1 year already. Could it be affecting the PH? A PH test I did 1+ year back indicated ph of 7.

Appreciate any help from you guys. Sad to lose my nice big cardinals.

[stormhawk]

If they had a large whitish patch at the rear half of the body, they might be affected with NTD aka Neon Tetra Disease, Plistophora. I think this illness affects other fishes too. No cure for this yet, you have to cull the sick fishes to prevent it from spreading to others.

About the stump of a tail, it probably got hit by a major case of tail rot / fin rot, or there's some other fish in there that's taking big bites out of them. I had one Boraras that had its tail almost ripped off by a hunting killie male.

[Danielone]

Stormhawk, I can rule out the fish being bitten by another fish,cos the rest are of similiar size.
As for tail/fin rot, is it possible to stop the spread/cure it by large water changes alone? Or do I need to add medicine? Reluctant to add any cos I'm afraid of affecting the plants and other fishes, esp my cories.

NTD affects cardinals too? I thought they only affects neons. It's like one or two small (1-1.5mm) air bubbles on/inside the fish, just perfectly white in colour.

[Justikanz]

Is this a cardinal thread? I have cardinals spinning in my tank! One by one, they would go into a few wild fast spins and then look concussed... After 1-2 days, I would spot a cardinal body... Seen this happening to 3-4 of my cardinals liao... But always one at a time...

Poisoning?? Or cancer? Swim bladder problem? Or???