Normally, Bettas and Rubberlip Plecos aren't recommended to be tank mates but if you think that they are getting along fine together then that is OK.
actually,i have a pleco(rubberlip), male betta, and two lake snails i found all in a ten gallon tank and they do great my rubberlip is only about 3 in long the tank still has plenty of room to so yes you could also add some other additional fish to the tank
yes! i have a rubberlip,betta and two medium lake snails living a happy life and growing steadily in a ten gallon tank,they are very heathly and happy and the tank isn't over crowded.
Yep! They'll ignore each other. Better have a big tank ready for the pleco when it grows, though.
None. The 1 gallon bowl is already too small for the betta by itself.
Forever.
Any.
No shark can live in a 3 gallon tank. It would be a nice home for a Betta though!
The tank would not be overstocked with what you have suggested, provided you have a filter running all the time and you do a 50% water change every week.
Provided you keep a filter running all the time and do a 50% water change weekly things should be OK.
A Long life for a Betta is around 30 months.
no plecos will die
First: a "janitor fish" is what Americans call a pleco. Second: yes, you can keep a Betta (fighting fish) and a pleco (janitor fish) in the same aquarium. Plecos are only aggressive to other plecos, so your pleco won't eat the betta. The two fish live in different parts of the aquarium--plecos at the bottom like most catfishes, bettas at the top because they're airbreathers. A betta has the common sense not to mess with a fish as big as a pleco--and it wouldn't matter anyway because plecos are armored fishes. Plus, bettas love to eat snails so they are a good addition to your tank maintenance team. Now! This is the problem: Plecostomus catfishes get huge--if your fish isn't a foot long two years after you get it, you're not feeding it enough. (Plecos eat things like zucchini pieces that you weight down so they sink.) It is a fish that needs AT LEAST a 55-gallon tank to live and be happy. If you've got a small tank like a 10 or a 20 gallon (40 or 80 litres) I would get either Ancistrus catfish (like plecos but much smaller), Corydoras catfish or upside-down catfish.