How long did you massage its abdomen? I might try this..not sure if this helps, but i had an aro once that floated like yours, what i did saw to hold it gently and i made it swim around, lika playing with a toy, and i massaged its abdomen GENTLY, then it swam as if nothing happened the next day....not sure if what i just did had helped it though
I really didn't know that higher temp can cause so much chain reaction..When temperatures are high any toxic reactions are worsened. you know when science teachers explain chemical reactions? and these are sped up with higher temps.
your ammonia becomes more toxic, cause the percentage of nasty ammonia is higher when the temps are higher. if the water is suspect or overfed, the water will also hold less oxygen when temps are higher. also, if there is an osmotic balance problem this will not be made better by increasing temps because respiration and cell activity is increased. turning temps down slightly will thus buy you the needed time to fix the issues.
If an arow is sick, why would you turn the temperature up unless the temperature was far too low and making it sluggish to begin with. so turning up temps should not be done if the temp is say 23c-28c and the fish takes a turn for the worse at those temps.
you might have been lucky, sometimes big arows will go on their side during transport and then have swim bladder issues.
I am not convinced that them going on their side is just a matter of them not being able to sit right way up and so then over time that sets in or if there is some other unnkown causeing this from the start. as in maybe they are stressed and groggy and it just gets worse..
anyway, if the fish can be held right, sometimes it will just work itself out and come good.
but if this is a true thing, you didnt want to wait and see if it was just a temporary balance thing or if it was a water issue. i really wanted to verify if your water had different calcium levels etc. sometimes tap water can have too much chlorine but you say you treated that but people can only go off the dose guides because they dont have a chlorine test kit on hand to really know what the water is doing, or to calculate the treatment dose.
People always say bump up the temp when the fish is unwell & I followed this guide blindly without even knowing what it does.. But I do know that higher temp increase metabolism..
& yeah, you are right.. I just follow the dosage guides for the chlorine treatment.. Don't have test kits available.. The ones I had aren't really accurate..