Fish Never Seem To Live That Long

I'm enjoying my small tank, had it a good few months now but I'm not having much luck keeping any one fish for very long.
It's a 30l biorb tank and after recycling it (with help from Think Fish folk) I regularly check all the levels and it's all been good.

I have only got platies in it, 5  at the moment. I buy them locally. They always seem perky, and they seem happy in my tank.
But after about 5 weeks or so - it varies, they seem to just keel over. Not with any noticeable disease that is apparent to me, they just die. Sometimes I can scoop out the body and look at it but nothing shouts at me that there's anything amiss. Other times they die but the body is gone before I can retrieve it.

So what am I doing that they don't live long? They seem so happy up until they die. Perhaps fish don't live long and my expectation is too high?

To add to Sue's comments :
Platies are highly inbred fish (to get the unnatural colour varieties) they do not seem so be very robust these days and many people have problems with them.
You would be better off with much smaller fish such as some tetras. Looked after properly, these fish should live for at least 5 years, some much longer.

With those numbers, your water is plenty hard enough for livebearers, including platies, so that's not the cause. And with water that hard your choice of tetras is quite restricted - most of them like soft water.


Look at endlers livebearers, males only. Males are small, brightly coloured and won't fill the tank with unwanted fry. You could fit 6 to 8 in the biorb.
Or celestial pearl danios aka galaxy rasboras, again about 8.
Maybe a shoal of the rainbowfish/blue eyes in the genus Pseudomugil

Just one of those, not all of them.

For live plants in a biorb, you need to look at those that can be attached to decor. Planting them in those rocks that are the substrate (and the biological filter medium) won't do plants much good. Look at java fern and the various species of anubias which can be tied to any decor, and will eventually attach themselves; or for a plant for fish like CPDs to hide in, try hornwort wound round a piece of wood.
It sounds backwards but many timid fish come out more if there are lots of hiding places. They know there is somewhere to run to if a predator should appear so they don't need to huddle in a corner. (If a biorb had corners  )

If you went for endlers, the task would be easier. They are not shoaling fish though they do like company of their own kind. So every time a platy died, you could replace it with 2 endlers. This would mean you wouldn't be stressing the bacteria colonies with too many extra fish in one go as you would be if you let the platies die off one by one before replacing them. Endlers are also not as shy as celestial pearl danios so you would see more of them. Just make sure you get all males so you don't risk overpopulating the tank. Females are easy to spot as they are plain grey beige while males are very colourful. They do come in several colour patterns so buying 2 at a time would give you chance to look around and get multiple patterns if you decided to do that rather than get all the same pattern.

Male endlers do chase each other. But they don't pick on each other. The group will swim round 'chasing' one fish, then they'll change direction and 'chase' another. I've had endlers on and off for years and have never seen a male endler harm another one - or any other fish. They will try to mate with each other, and the remaining platies. That's just livebearers.


The only downside to endlers is that they do not have a terribly long lifespan - 2 years is a good age. But all you do is replace them as they die of old age.



Since you have platy fry, are they old enough to tell the sexes yet? Keeping males and females in a small tank is never a good idea or the tank will be overpopulated very quickly. If the fry are still young, they'll all look female. It takes a couple of months for the males to hit puberty and start to change.

I know that feeling. My husband isn't a fish fan, except when the fish is on his plate