How do you know if fish is dying from an old age?

Since none of my LFSs post the age of fish (I never seen any fish store do, probably no one does lol) how do you simply know the fish is dying from natural old age or they actually have a disease?

I have a platy for 4 months which is my first fish ever. He was about inch and a half when I got him. Lives with 4 other platies and 8 neon tetras in a 20g. Went thru 2 ich outbreaks and survived them both. Last ich I decided to treat with heater set up to 86 but it was only that temp for 3 days until I switched to apI super ich treatment which treated the ich. I had dwarf gourami that died from it but overall ich did take over 2 weeks to disappear(maybe it wasn't ich but each fish did have few white dots). About a week after no ich, this platy is weak in a sense of swimming, bumping into things and laying on the floor. No visible signs of disease. No white dots, no clamped fins, nothing on the body to indicate any sort of abnormalities. He still tries to come up for food but doesn't know where it is . Water specs are all good pH 7.2 rest zero nitrate never goes above 40ppm and I do weekly water changes.

Could my platy be simply dying from old age or last ich outbreak messed him up? How do you know if fish just reached its peak in terms of age? What would be my next steps to try to get him to get better? Please help

 

I doubt a platy would die of old age after just 4 months of having him. Dwarf gouramis are notorious for having poor health right from the get-go. Fish also don’t die from old age, but from diseases and other things that can penetrate a weaker immune system of an older fish.

I think you mostly got fish that are known to be weak from bad breeding.

 

I doubt a platy would die of old age after just 4 months of having him. Dwarf gouramis are notorious for having poor health right from the get-go. Fish also don’t die from old age, but from diseases and other things that can penetrate a weaker immune system of an older fish.

I think you mostly got fish that are known to be weak from bad breeding.

But every fish has a life expectancy and platies have 2-3 years, especially mass bred like every fish nowadays in LFS. How do I know if I didnt get a 2 year old platy and now it's old and easily gets sick? There no easy way to tell age, is it?

 

But every fish has a life expectancy and platies have 2-3 years, especially mass bred like every fish nowadays in LFS. How do I know if I didnt get a 2 year old platy and now it's old and easily gets sick? There no easy way to tell age, is it?

Well, there really is no way to tell with fish like platies. If he was 1.5 inches when you got him, that’s a pretty good indicator that he may have been young, though. I avoid livebearers because no one seems to care about their breeding, so you can end up with fish in really poor health that indeed only live 4 months, but it’s not old age that kills them. It’s their bad genetics that opens them up to diseases. I also have a tendency to somehow end up with livebearers that like to nip my fish incessantly, but that’s another story for another time.

 

There is no easy way to tell age if you do not breed ..Breeders can tell.
A fish at your regular LFS [ or box store ] that has normal price on it are average selling age fish .That would be 4-8 months for most with younger being more the norm ..I say this as no fish farm wants to keep a fish longer [feeding ,housing care and possible loss ] then they have to .If it is saleable they send it .
I breed fish and you would be better off getting fish from breeder IMO ..
Look on Aquabid there are livebearer breeders in NYC for sure ..

I will guess it is probably the repeated treatments that have worn out your platy ..There is a price to be paid for using meds too often ..

 

There is no easy way to tell age if you do not breed ..Breeders can tell.
A fish at your regular LFS [ or box store ] that has normal price on it are average selling age fish .That would be 4-8 months for most with younger being more the norm ..I say this as no fish farm wants to keep a fish longer [feeding ,housing care and possible loss ] then they have to .If it is saleable they send it .
I breed fish and you would be better off getting fish from breeder IMO ..
Look on Aquabid there are livebearer breeders in NYC for sure ..

I will it is probably the repeated treatments that have worn out your platy ..There is a price to be paid for using meds too often ..

Thanks for the insight. I used meds twice and was told platies are hardy fish for beginners so that's what I got (all of em are from Petco...). Others are going strong and went thru both ich outbreaks so I'm hoping they will be fine for a while. I don't have space for quarantine tank in my small apt so I'm risking it with new fish added to tank. That's how I got second ich from neon tetras I think

Well, there really is no way to tell with fish like platies. If he was 1.5 inches when you got him, that’s a pretty good indicator that he may have been young, though. I avoid livebearers because no one seems to care about their breeding, so you can end up with fish in really poor health that indeed only live 4 months, but it’s not old age that kills them. It’s their bad genetics that opens them up to diseases. I also have a tendency to somehow end up with livebearers that like to nip my fish incessantly, but that’s another story for another time.

the only bad luck I have is with guppies I had 4 die in past 2 months and I gave up on having them again. Now I have only 3 left in 10 gallon tank (had 5 total after buying more later) but I think I will buy no more from now on lol

 

Anything I can do to save this platy? I've heard of salt bath but never done it. I will be doing 50% WCh tonight to see if that miraculously does anything but beyond that I am not sure what else I can do not using medicines

 

Some fish are just weak also .If your others are good then likely it is weaker .
Water changes are the best ..You have soft water in NYC huh ?? Got a few buds your way with TDS around 40-50 !
Look into Wonder Shells for your livebearers ..
I use them for my swordtails and my tap is 350tds ..
Livebearers really like harder water

 

Some fish are just weak also .If your others are good then likely it is weaker .
Water changes are the best ..You have soft water in NYC huh ?? Got a few buds your way with TDS around 40-50 !
Look into Wonder Shells for your livebearers ..
I use them for my swordtails and my tap is 350tds ..
Livebearers really like harder water

Yes NYC has very soft water. I'm using crushed coral in the filter and some in the substrate. Last time I check my GH was 6 and KH 3. Also had pH 6.6 before crushed coral. Mind you it took 8 weeks to cycle with the platies in there with no deaths (just one ich outbreak). In week 7 I decided to slowly raise the pH with crushed coral to 7.2 and used TSS+ cuz I was running out of patience. Cycled right after. So these platies have been through a lot

 

This is a good question but one without a good answer. Very little is published about lifespans in most tropicals. My only data would be my upside down catfish which was very small when I got him. He died 14 years later and had a bad case of cataracts on both eyes. I assumed he passed from age related issues.