Cardinal Tetra - A Few Odd Features

THIS POST WAS ORIGINALLY IN 'THINK FISH DAILY NEWS' BUT MOVED HERE INTO A NEW THREAD INSTEAD
fcmf 

and I'm fairly sure I know who'll be next to go - a rather large female who is eating herself obese and breathes heavily a lot of the time (I've also read of others finding this with cardinals), as well as a couple of other changes I've noticed which may or may not be of any concern.

Hmmm - I have a feeling this may be sooner rather than later. The other changes I'd noticed in this particular fish in recent months were her gills becoming slightly dappled rather than completely red (although not particularly concerning me), an internal lump under her chin (I actually wondered if she'd ingested some sand and it's been stuck in her throat) but this is developing into a sort-of double-chin/jowl in recent days, and the part over her spine and dorsal fin becoming more transparent when viewed from above. I wasn't entirely sure if the latter was just what happens as cardinals mature and become larger so that the blue stripes become more on their sides rather than almost meeting at the top. Anyway, there's a further development today - she's spending a lot of time nestled in one of the silk plants albeit not sitting in it... but I have an inkling this isn't looking too good.  Given that the first tetra didn't react at all well to Epsom salts, eSHa 2000 and/or being isolated, I'm not going to remove her, and I'm not entirely sure what I'm dealing with, but I don't think it bodes well.  Photo attached of her earlier on.

Thanks, LF.

I checked in the main tank 30 minutes after 'lights off' - 3 fully-coloured cardinal tetras, 2 washed-out.
The 2 washed-out are the fish referred to above plus a small male.  I had noticed that, over the past week or two, the small male was breathing faster than the others intermittently - but not as frequently as the obese female (the obesity is only evident when she's face on or at an angle, not in the photo).  This week was when I noticed the part over the spine and dorsal fin becoming transparent when viewed from above (this can be partly seen in the photo) - in both the female and this male.  However, I assumed this was as per my thoughts above.  However, the fact that both are washed-out after 'lights off' suggests something's up with these two.
Water quality is as per usual (0,0,20) on the test kits (although currently no test strips against which to cross-check my nitrate which is always difficult to read).
Having had a little search online, there seems to be one condition that some of these symptoms are consistent with, albeit that particular condition does mention other earlier/key symptoms that are more likely to occur and that I'm not noticing - yet.  Interested to know others' thoughts, particularly from the photo. 
Mr FCMF won't be best pleased if the isolation tank has to come out yet again...

Tomorrow I'll give an update on my tank, as I'd really like to figure out if there's anything in my fish husbandry that's accounting for this.

Pleased to report that the paler/transparent/washed-out colouring over the spine and dorsal fin area is no longer evident during the daytime, either with lights out or with lights on. The faster breathing or opening/shutting of mouths is less than it was - more what I'd describe as within normal range. I had begun to wonder if it was neon tetra disease, albeit I would have expected patches of discolouration rather than the whole area transparent. Not sure about night-time - the large female was still looking a bit washed-out nestled in the silk plant last night but will see how the situation is tonight after a day of looking better.

This has given me quite a jolt, just how easily nitrite crept up to 0.25 and the consequences (and that there must have been ammonia presence since the last water change 4-5 days beforehand). Needless to say, I've now sent off for more test strips so that I can cross-check nitrite and nitrate against those, and will make sure I do readings in natural daylight in future and Mr FCMF's eyes' interpretation too. As a precaution, I've also sent off for an Ammonia Alert reader. Thankfully, JPC had mentioned ITS Europe test strips and the Ammonia Alert reader and where to find it cheaply, so have opted for those - thanks, @jaypeecee .

Nitrite back up to 0.25, so another large water change planned for today.

0.25 nitrite again today, so another water change undertaken.

Potential explanations [and likelihood of it accounting for the problem]:
* tropical mix frozen food fed on Mon: to get rid of any nasties, I rinse it beforehand with half a kettle of boiling water followed by thorough rinsing in cold water, and there was less food than usual as I’d inadvertently used the larger net during rinsing and lost a lot through that; [unlikely];
* limnophila sessiliflora had been very thick and long: although I separate the strands most days to release any fish food caught in it and rotate the strands a couple of times a week to remove/reduce algae (usually brown although looks more black on removal), I had a bit of a poke 7-10 days ago near the base with the aquascaping tweezers to remove any clogging the roots, and unfortunately caused most of the stems to break – they seemed weak and almost melting, held together by the brown algae; I left the long green but root-less stems in tank as floating plants, removing only those that looked dead; [possible];
* JBL Atvitol started daily on Mon as fish food been open for a while and to keep it vitamin-rich (had been using it intermittently prior to that); [unlikely - doubt the product would sell if it affected water quality;]
* as per photo, I’ve been tucking extra filter media into each of the slots by the filter intakes, more-or-less from the start of getting this filter over two years ago; recently, though, I’d put portions of thick/coarse phosphate pads in there. Although this had never been a problem with the filter sponge/wool, I wonder if the thick phosphate pads were impairing the flow of water and causing beneficial bacteria in filter to die but NB it wasn’t impairing filter outflow – cf https:///www.youtube.com/watch?v=gO9gWa_G8L0. [most plausible explanation so far, and @jaypeecee may have a view on this given that he has had this brand/model of filter before].
Views welcome, including if anything from my previous comments may suggest anything.
For definite, I haven’t forgotten to add Seachem Prime – very particular about keeping alert during water changes and ensuring that it’s added.

Thanks.
Good re the JBL Atvitol.
Phosphate pads pack says replace monthly. I didn't make a note of when I last replaced them but it's possible they could be up to 2 months old. I use them because my phosphates are 5 on the API test kit for both tapwater and tankwater (orthophosphates are added to water by supplier). I notice that they're closer to 2 now, having had the phosphate pads in. Algae in the tank itself has never been bad at all - nerite snails may be addressing any - but plants do get some sort of brown algae, sometimes like diatoms (possibly high silicates) and sometimes more stringy and sometimes fluffy, and the anubias gets a little BBA.
Ammonia reading was absolutely fine - but I can't be certain what happened during the 4-5 days between the last water change and when I detected the nitrite presence.

Sorry for your loss @fcmf

Oh dear, @fcmf

I'm sorry to hear the latest news about your Cardinal Tetra. 

My hunch (and that's all it is) is that this nitrite problem is not likely to have been caused by the wood. May I ask what is the nitrite reading straight from the tap and after treatment with Prime? Water companies need to ensure that the maximum nitrite is 0.5 mg/l. And, FWIW, my figures for 2019 were 0.01/0.01/0.01 mg/l (max/mean/min, respectively). Throughout the year, there were just 8 samples taken. I find it difficult to accept that the max/mean/min were all the same value in my case. Do you have figures from your water company, whoever that may be?

JPC

Hi @fcmf

OK, interesting figures thus far. Please keep us updated. In between watching the NASA activities, I managed to find some real fish toxicity figures for nitrite. There is some dependence on chloride in the water but I determined that the maximum permissible nitrite level is around 0.05 mg/l (ppm).

JPC

Quote from: jaypeecee on May 31, 2020, 04:00:54 PM

I managed to find some real fish toxicity figures for nitrite. There is some dependence on chloride in the water but I determined that the maximum permissible nitrite level is around 0.05 mg/l (ppm).

Have I interpreted this correctly that, although both your and my water companies state that 0.5 mg/l is the maximum permissable nitrite level, any level around 0.05 mg/l (ie ten-fold lower than that) is actually toxic?

Hi @fcmf

Yes, your understanding of what I have reported is, indeed, correct. We have to remember that the maximum limit or PCV* is the figure that applies to we humans, not fish or other tank inhabitants.

I know this will be of no immediate help but have you considered using re-mineralized rainwater in your tanks? Or, mixing rainwater with your tap water? You do seem to have a few problems with the latter.

JPC

* Prescribed Concentration or Value

Hi @fcmf

Thanks for the feedback.

It sounds like your tank nitrite and nitrate are good-to-go. Please note that the figures you see above the ITS colour patches need to be multiplied by 4.4 for nitrate and 3.3 for nitrite. There is a note to this effect (in dark blue) on the front of the container. That's why the colour patches are labelled 'NO₃-N' and 'NO₂-N'. Being a USA product, that's how they present their measurements. Just put a big mark on the cap to remind you to get your calculator out whenever you use them!

Please keep us updated.

JPC