We are having some trouble with our fish tank, we are worried it has some parasite or disease. We had one guppy die last week (it appeared to be suffering from swim b!adder), then a sucker fish suddenly died yesterday and now one of the plants is just sat on the bottom in the plants. He does appear to be able to swim in though. The shop recommended swim bladder medicine but I'm unsure if we can use it since we have shrimp, snails and sucker fish in the tank. Thanks
Can you post test results please, for ammonia, nitrite, nitrate and pH? Also size of tank, list of fish and other creatures in the tank, how long has it been set up and how often do you change any water?
The tank is 125l and in it currently we have 5 platies, 4 guppies, 2 otocinclus, 3 shrimps and 2 snails. The levels are all good, the ammonia is 0, nitrates 20 and nitrite 0.5. We have had the tank running for 4 weeks now. since last posting we have seen the platy, who we thought was ill, being bullied by a guppy. We believe he was on the bottom in the plants hiding, he appears to be venturing out more today. However when we came home we found another otocinclus dead, the previous one died Tuesday, and we have no idea what it causing it.
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.