If you can let us know what your water hardness is, either in GH and KH from your water testing kits or else from inputting your postcode into your water/utility website to get water hardness results in CaCO3 or German degrees hardness, that would be really useful for us to help you choose suitable fish whose water requirements match those of your own water.

[I see, from a previous post of yours, that you were asking about Tetra Safestart .v. other products. What approach did you use for the cycling process ultimately and how have you found it?]

Sorry for not being able to reply yesterday as intended. I'll need to be brief but, essentially:

* flicking *might* be a disease but more likely to be a water quality issue (which doesn't necessarily mean that death is not imminent - acute or chronic water quality problems can result in death - but hopefully following this advice will minimise that risk);
* when cleaning filter, a gentle squeeze of filter media into being-discarded tank water is all that's required (don't over-clean it or rinse in fresh water, otherwise you'll lose the beneficial bacteria required which processes the fish waste);
* internet advice contains a lot of incorrect advice as well as 'bona fide' advice, so caution must be aired; this https://www.fishkeeping.co.uk/modules/ ... esheet.php?caresheetID=73 and this https://www.seriouslyfish.com/species/tanichthys-albonubes/ and http://www.fishbase.org/summary/Tanichthys-albonubes.html are 'bona fide' sources about these fish's requirements in terms of minimum tank size, minimum numbers, and lots more. (These aspects are much more important than lighting and planting ie neither over-lighting nor over-planting are likely to have any adverse effects.) With the wealth of info out there on so many aspects, it's difficult to tell the 'wood from the trees' and the relative importance of different aspects, but these caresheets should keep you 'on track'.

Hope that's helpful.

Keep monitoring your ammonia, nitrite and nitrates *daily* for at least the next month / a month after you move the fish into their more appropriate-sized home, to ensure that you get through the cycling stage. For such a small tank, this may very well require daily water changes of whatever quantity required to keep ammonia and nitrite at 0 and nitrates no more than 20 - these readings need to remain at this level every day. Stress, through too-small an environment, can also play havoc with fish hormones and secretions of these in turn affects all tank inhabitants, but this can't be measured through home-based test kits; even small daily water changes should help address this, though, by diluting levels of these hormones.

When you move the fish into their new home, it will be crucial to preserve any beneficial bacteria that you have in the filter media so that it can continue to process the fish waste, and not let this die off - it starts to become dormant within an hour or so, dying off thereafter. Therefore, after the new tank has been set up with substrate and dechlorinated water:
* if you're not intending to use a new filter in the new tank, move the filter and its media straight into the new tank along with the fish [no need to do a fishless cycle on that tank's filter unless you're planning to increase your stock];
* if you're intending to use a new filter in the new tank but not the old one, transfer across all the filter media from the current filter into it along with the fish;
* if you're intending to use both old and new filter in the new tank, keep half the filter media in the old filter and put the other half of the filter media into the new filter to seed it.

After about a month, then taper off the water testing and just do it once a week thereafter, just before the scheduled water change, to ensure that you're managing to keep the water quality at this level throughout the week and up to immediately before the scheduled water change.

Hopefully this, and following the excellent advice in the link that Fishlady gave you, will help reduce the flicking - very often a cause of fluctuating water quality / the fish-in cycle. [Been there, done that, albeit in the pre-internet days when these forums didn't exist.]

If you didn't do a fishless cycle by adding an ammonia source to mimic fish waste and thereby prepare the filter in advance to be able to process the fish waste (https://www.fishkeeping.co.uk/articles ... hless-cycling-article.htm), then the main cause of your problems is likely to be due to a fish-in cycle. Even off-the-shelf products of beneficial bacteria claiming to accelerate the cycle are extremely 'hit and miss' in terms of effectiveness.

Keep monitoring your ammonia, nitrite and nitrates *daily* for the next month or so, to ensure that you get through the cycling stage, if need be doing daily water changes of whatever quantity required to keep ammonia and nitrite at 0 and nitrates no more than 20 - these readings need to remain at this level every day. After about a month, then taper off the water testing and just do it once a week thereafter, just before the scheduled water change, to ensure that you're managing to keep the water quality at this level throughout the week and up to immediately before the scheduled water change.

Plenty of plant coverage and hiding places will help in terms of the bullying, as well as keeping the water at optimum quality as described.

Otocinclus have a tendency not to fare very well - sometimes they starve in the transport process from the suppliers and can never quite "catch up" before this ultimately takes its toll. Generally, they're best added to a mature aquarium - ie one which has had 9+ months to develop a biofilm on the tank's surfaces - in order to fare better. Corydoras are similar although not quite as sensitive. I'd advise *not* replacing the otocinclus or buying corydoras. In 9+ months' time, you could re-consider adding them, and in greater numbers, perhaps supplementing their food - see https://www.fishkeeping.co.uk/modules/ ... sheet.php?caresheetID=100. This sensitivity, on top of a fish-in cycle, is likely to account for their demise.

Hope this helps. :)

I'm not able to reply fully just now but will do so as soon as I can. However, in the meantime, I'd advise reading:
https://www.fishkeeping.co.uk/articles_12/keeping-goldfish.htm
https://www.fishkeeping.co.uk/articles ... -size-life-expectancy.htm
https://www.fishkeeping.co.uk/modules/ ... esheet.php?caresheetID=83

Also, a few key tips:
* if you can buy one of these to keep the goldfish in http://www.reallyusefulproducts.co.uk ... eshop/rub/b145_0litre.php until you get a suitably sized tank, that ought to help a lot, whereas even daily water changes in the bowl are unlikely to be anywhere near sufficient;
* you'll also need to buy a filter to process the fish's waste;
* ensure you treat the water with dechlorinator that treats chlorine and chloramine as many water companies treat the water with the latter too now;
* liquid-based test kits for ammonia, nitrite and nitrate are crucial [API Masterkit ideal];
* I wouldn't overly concern yourself about the lighting - my own goldfish lived for a decade and a half without artificial lighting at all as he hated it;
* best to feed the fish food specifically for goldfish, as it will be formulated for their specific requirements and digestive tract - and also read this http://injaf.org/aquarium-fish/the-go ... /goldfish-and-their-diet/
* white spot treatment is also a good treatment to have on standby.

If the scales are spiky, I suspect dropsy has likely developed. The bacterial infection treatment is probably the best course of action in case that's the cause (and the red fins could also be symptomatic of that) but I wouldn't bother with the aquarium salt for now - it ought to be diluted with the water changes but don't put any more in.

Will reply more when I can which might have to be tomorrow, unfortunately.

PS. By 'they', are you referring to this one fantail/fancy goldfish?

The current stock you have definitely is not overstocking for the size of tank you have - the tank ought to be able to stock a shoal of 8-10 cherry barbs, the 5 platy and 8-10 cardinals (and the increase in numbers of cherry barbs and cardinals might help these shoaling species feel less stressed and possibly even the flicking behaviour of the sole cherry barb). I'll explain later how this would need to be done, though.

In terms of your current problems, I think it would be worth going into some LFSs and checking the consistency of their foams for different filter brands - if you can find one that would "fit the bill" for the part of the filter where the carbon/polypads were, and possibly even in the Biomax compartment in lieu of the Biomax, then hopefully you can cut/trim/shave it to size. It might even be that you chop or double up the current foam in order to best accommodate this extra foam - as long as the existing foam remains in there, it doesn't matter how it's placed (cut/folded, etc).

The addition of the 6 cardinal tetra at the end of January will have increased the bioload considerably, because essentially the beneficial bacteria which you had will have to process the waste/ammonia of twice the number of fish. That may have caused a mini-cycle or even a full cycle to occur, which may account for ongoing ammonia presence.

The best way to add new fish is to quarantine them in a separate tank for a month or so, with a portion of existing filter media (which will contain the beneficial bacteria) transferred into the quarantine tank's filter - it's generally safe to remove up to 1/3 of existing filter media. In the main tank, replace the being-removed portion of media with new media, ensuring that the existing media has direct contact with the new media to "seed" it with the beneficial bacteria. Once the quarantine period of time is over, move the quarantine tank filter into the main tank as well as the new fish, so that all the beneficial bacteria required to process existing and new fishes' waste is in the tank. You could then either have the quarantine tank filter in there on an almost-permanent basis, to easily remove and put in a quarantine/hospital tank as required or else you could gradually remove a small portion of media from it every few weeks, so that the main tank isn't in danger of losing too much of the beneficial bacteria at a time (which processes the waste of all the fish), before eventually removing it and just keeping the main filter in the main fishtank.

When you replaced the Mini with the U1, did you transfer the media from the former into the latter? If so, that oughtn't to have had an adverse effect. If you didn't and instead discarded the Mini's filter media, that may also have caused ammonia to be present/increase, in addition to the extra ammonia from the new cardinals.

Continue doing water changes with double doses of prime, perhaps every alternate day or whatever it requires to keep ammonia at 0 (and nitrite), and hopefully this will get you "back on track", in conjunction with the filter media as described above. Don't even consider adding any new fish until you get this process under control for at least a month with 0 ammonia daily. Only if you manage to get all under control for at least a month, then consider adding stock as described above - you could perhaps quarantine and then add 5 cherry barbs in the first instance, then if/once the main tank seems to be settled with stable 0 ammonia readings from that, then consider perhaps 3 more cardinals and 3 more cherries in the second instance (the Mini or U1 ought to support each of the two batches of 5 or 6 fish at a time during quarantine in the way I've described).

Hope that helps.

I'm not good at keeping live plants and so am fairly familiar with silk and plastic alternatives. Although I haven't used plastic grass (yet), some suggestions of options to help keep it weighed down might be:
* glass pebbles
* miniature terracotta pots laid on their sides
* silk plants with weighted bases such as the Oase/Bi-orb ones
* moss balls (may not be heavy enough though)
* rock, wood or even stones/wood with anubias attached to it

You can lay most of these in such a way that their location looks more 'natural' than evenly spaced specifically to hold down the carpet, and perhaps hides/softens the edges of the carpet.

Hope that helps.

Quote:
In their defence, mine have "grown" on me and I now feel they're understated. Their tails are blood red, their fin colouring/patterning really stands out, and their eyes are good for making eye contact with (a feature I favour). The females in particular were very entertaining but that may have been unique to them, and it was particularly eventful when the males set off en masse in hot pursuit of a female, although I now just have males left. However, if they're not easily available, then perhaps Fishlady's alternative option might appeal to you better and be more widely available.

Hmmm... quite a lot of the fish I was thinking about (eg danios) need lower temperatures.

Cherry barbs or microdevario kubotai might be options but 27 degrees is right at the top of their range and your water hardness may be a little on the soft side for the cherry barbs.

Will continue with having a think about alternatives...

Good that they seem fine so far.

I'd recommend giving them a break from feeding today and possibly tomorrow too. This will do them no harm at all and is likely to be of benefit. Conversely, if you gave them some peas as well, there is a possibility that the combination of the frozen bloodworm plus the peas may bloat them or produce too much of a laxative effect.

Hope that's helpful.