tHEcONCH

Quit the meds, do a large (75%) water change, and fill the tank back up to capacity. Do another big (50%+) water change again tomorrow. Make sure there is plenty of surface motion (install an airstone perhaps) to make sure the Oxygen levels are good. I don't know what your water is like, but make sure it has some kH - add something like JBL AquaDur and bring it to at least 8ppm. Its a popular misconception that Discus need supersoft water all the time. In nature it is soft, but not nil kH, and it never runs out - in an aquarium you need to add some back to RO water etc. to help with bone formation etc when they are growing. Add Vitamins to their food (don't overdo it and foul the water) or use a vitamin enriched food like JBL Grana Cichlid. Expect as few more to die off (its already too late for some), but numbers should stablise. Good luck.

Who / what is TM in Christchurch? Another member?

Don't be fooled by appearances - they are quite different fish. Cardinals generally have more colour, are a little bigger, and live for much longer in a well maintained tank. Historically they were considered impossible to breed in captivity (unlike neons), although that isn't the case now. All those factors mean that they command a higher price than neons which, although still a very nice fish, don't have the same visual impact or value as Cardinals, especially in bigger tanks.

The only thing I know eat snails are large cichlids - especially Oscars and the like. They'll eat everything else that they can get into their mouths too. Other than loaches, some larger Plecs are the only fish I know will eat eggs, but usually as a bit of a 'by-catch' when eating surrounding algae. I suspect they don't taste so good.

Good result!

It also kills pencil fish, so be careful. I've had mixed results with that stuff, and no longer use it.

It is evil. It gives you cancer. It can also be a useful remedy for ailments that can be avoided by keeping your tank clean, but it does seem to have negative side effects on the nitrogen cycle (and suspended oxygen levels) in my experience. Use it as a last resort.

Does it have plenty of wood to eat? They need to eat wood to help them digest food. Try some JBL Plecochips (they contain wood and algae).

Are you mains or battery operated?

Save yourself whilst you still can...

How's your fish doing?

Bummer.

Judging by the colour, it is almost certainly ReefRoids (I've been direct feeding it) + perhaps a bit of mashed brine shrimp (spillage from feeding the Sun Corals). It also seems to 'get interested' when I clean the brown diatoms off the glass, so maybe it will eat any small organism.

Hmmm... so I got up early this morning and discovered that the Chilli inflates to nearly twice its day time volume at night, with super-extended polyps - and the coolest thing is that you can see the food in them (the 'stalks' are transparent when fully extended). Will try and get photos, but it retracts when the lights go on. It is definitely carnivorous :lol:

Yep, mine do that from time-to-time. They tend to lay long waves of eggs rather than the usual snail clump. They don't seem very 'sticky', and most of the time end up in the skimmer.

Ah, just stick it back in - it'll be fine :lol:

That's normal - keep rinsing it until it stops.

That's probably it then - infected bites compounded by a bit of stress. Do water changes and / or treat with Furan2. (I'd be inclined to not treat unless it gets worse over the next day or two - Furan is horrible stuff)

Just syphon it out / blow it into your skimmer with a syringe.

The fish load sounds OK, but you may have killed the bacteria in your filter when you trated the whitespot which means that although you can't see it, your water is full of toxins. Do a good sized water change and add some Cycle or similar.

I once had a female get similar looking little white infections after three weeks of heavy feeding by a particularly large brood - they healed without treatment once I removed the brood to a raising tank. On the plus side your fish still looks to have some flesh on its bones, so it may just have succumbed to some sort of local skin / slimecoat infection rather than a systemic disease - I note it has what looks like bite damage on the rear of its dorsal fin and two whitish areas on its tail that look like a bacterial infection. In any event, Furan2 is probably still the best option, but be careful how you handle it - its pretty toxic stuff.

It sounds like bad water to me. You need to do a 50% water change now, regardless of whatever else you do. If you've recently treated for whitespot the residual meds can upset the fish in other ways, so you need to make sure it is all gone by putting charcoal (or charcoal pads) into your filter to remove the last of it (take it out again after 3 days).

I've had breeding pairs breed happily for years and then all of a sudden one will go into decline for no apparent reason. Its sad, I know, but they just don't live forever. Judging by its general condition, even if you were able to kill off any flukes or other pathogens, your fish will already have severe organ damage. There really is very little you can do now. Chalk it up to experience, and make sure you do your best to look after your other Discus.

Yup.

I think that is probably because it was / is the runt. Now that it is on its own and the others aren't hassling it, it will feel happier and display more colour, but it is on its last legs. You may be able to keep it a while in a seperate tank, but it really doesn't have too long. Its up to you what you do with it, but don't be too upset when it does go to the big ocean in the sky.