so tyre tracks wont share with other eels?
well it depends. if the tyre track is in the tank and have already established a teritory it will hassle any other eel it finds.
i had a 45cm tyre track and the 55cm fire eel for a good couple of years (bought both on the same day at about 10cm) and they lived happily together until i removed the fire eel to a hospital tank (had a skin infection) for three weeks.
i then returned the healthy fire eel to the tank and the tyre track started attacking the fire eel. eventually had to get rid of the tyre track because he kept on biting the fire eel.
so if you introduce a tyre track with another eel at the same time you have a better chance of successfully keeping a tyre track and another eel together.
in my experience however tyre tracks are the most agressive of the spiny eel family so be carefull if you want to introduce another eel. also bear in mind they top out at about 50cm, so it will get quite big.
another thing to try is to remove the tyre track when you want to introduce another eel then move all the decor around and introduce the new eel first, then a day later put the tyre track back. apparently the eel will then have to establish another teritory and this will stop them from atacking other eels they come across. personally i have never tried it.
will you be getting more eels? correct me if i am wrong but a 100g is about 450 liter?
(not sure in sa we use the metric system.)
if it is about 450 liter you should be able to keep more, obviously depending on the stocking level and the type of eel you want to keep.