Sorry to read about your loss. The Tank temperature should be at about 80 to 84 degrees Fahrenheit. The PH should be in the 7.0 range. What is the Ammonia level in your tank. That should be zero or near zero. Also, what about your Nitrites (not Nitrates). Nitrites should also be Zero or near zero as well.
Nitrite was today (main tank) zero and i bought ammonia tester and it was also zero. Tests were done after water changes and filter cleaning so it doesn't mean these were zero before things got bad. However i have tested nitrate before when water quality seemed bad and it was ~50 mg/l. PH was 6. I wish i had tested nitrite and ammonia back then. I thought the pH is so low because of driftwood but apparently it was organic matter in filters that made pH go so low and maybe there were high ammonia levels too? We will never know. I have to keep testing pH if it gets low again. I don't think buffering is necessary but we will see.
Temp is always >+28 °C. Summer +30-31 °C. I have tried to replicate Rio Xingu temps because i also have L81 which is from the same river. It has been growing pretty well (1.5 years, from 2" to 6"). As far as I know lower temps are harmful in long term for these fish. Aeration is at max with a powerful streamer.
PH in now 7 in main tank and 7.2 in quarantine tank. I have measured lower readings before as i have said.
It seems fish in the main tank has been more active today and yesterday since i have done some actions to water quality. In quarantine tank L203 has ate cucumber and tasted JBL Novo Pleco XL-tablet.
Sorry to hear that. Something doesn't seem right. Your nitrate level is not that bad. But shouldn't have stayed the same when taken two days apart with a 35% water change in the middle. How are the nitrate levels in your other tank? Perhaps the test kit is off. See if you can maintain a low nitrate level in your q tank. It should be fairly easy, if not, try another test kit.
Bio io media is not as fragile as what most people says. Just wash with aged water around the same temperature or tank water. Heck! Most people can get away with rinsing them in tap water. Yes, you'll kill off a lot of the beneficial bacteria. But mist bio media are designed to have a lot of surface area by having nook n crannies that's very hard to reach. So a quick rinse of tap water doesn't really hurt that much.
also don't forget that you'll probably have more surface area for beneficial bacteria from your very porous driftwood and sandy substrate . From your bio media. So wash away!
I thought the same. Weird that nitrate didn't go lower after water changes. I did a test today again and i think nitrate is now 20 mg/l. Maybe test accuracy isn't that good. I always clean my filter media with tank water. Q tank nitrate is now 12.5 mg/l which is pretty good. I did a filter cleaning after medication and water is clear. I'm not a fan of drugs because it messes up bacterial balance in fishes and everywhere else, because med kills all kinds of bacterial, good and the bad. I believe in natural immune system by providing healthy diet, vitamins and chemical free environment. Actually i doesn't have used water conditioner liquids for a long time because it also binds good minerals which fish need to thrive. I don't recommend this to everyone cause everyone doesn't have so clean tap water. Chlorine can be evaporated from water, but not all heavy metals and human drug residues. However minerals can be added afterwards with non-raffinated sea salt if water conditioner is being used. I will buy "vitamin drips" for future use. If i could go back in time i wouldn't have used medication at all and would have cleaned filter right away to provide as clean water as possible. I would have had add vitamin drops, sea salt and that's it. In other words i would provide best possible conditions for fish's immune system to fight back.
I think especially L81 is an good example of bacterial loss by chemical use in fish import since it's cut is very long and bacterial biodiversity and balance plays a big part of it's surviving in the wild and captivity. That's exactly the same thing as our use of antibiotics and what it causes to us, maybe symptoms are not so extreme. I think this is the reason why many fishkeepers have problems to keep gold nuggets alive and usually they don't grow so big in captivity.
