I agree with Mikaila31, russ1979 unless you plan on getting a 4-5x2ft tank then you should serious consider rehoming the bala shark, clown loaches and sailfin plec. You should not be keeping tiger barbs, male siamese fighter and a gourami all in the same tank together regardless of its size as these fish simply do not get along (if they aren't already at it, the tiger barbs will attack the gourami and fighter and the fighter and gourami will fight each other).
You should not buy fish which you do not know exactly what they are, pleco's vary massively in their care and size, so you really should get a good ID on your mystery pleco, as you cannot say for sure you are looking after it properly until you know what it is exactly.
Cories, tiger barbs and bala sharks are all schooling and shoaling fish, corys should be kept in groups of their own type of 3-5+ and bala sharks at least 3-5+ and tiger barbs 8+.
Please research your fish more thoroughly in the future, as looking after your fish properly is a matter of responsibility and you need to know exactly what is best for your fish to look after them to the best of your abilities- you have a fair few fish which will outgrow the tank in time to come (sailfin plecos can grow to 15inches+, clown loaches to 12inches+ and bala sharks to 10inches+) and many fish which should really be in larger groups or should not be kept with some of the fish you are keeping them with at all, regardless of numbers or tank size. There is also a question of habitat too- the ideal habitat for a siamese fighting fish/betta is very different from the habitat that is ideal for a bala shark or sailfin pleco etc.
edit: On the subject of over-crowding and whatnot in general, over-crowding is a different matter to over-stocking; a tank could be over-crowded but not over-stocked and vice versa. The most important thing is what type/s of fish you are keeping, the fishes activity levels, the numbers of the fish you are keeping in the tank, their sizes, the character/personality of the fish, the strength of the filtration and the exact measurements of a tank. Tanks vary massively in size, a fish could be fine in one long rectangle 50gal but not fish in a tank 50gal hexagon shape tank etc.
As you learn more about fish, you will get a better idea of what is ok and what is not ok for that particular fish- there is a lot to learn about any fish in the hobby, research often never stops. The worst thing to do is to stock a tank ignorantly- not knowing all there is important to know about your fish could mean you putting your fish through unnecessary stress, and one of your goals in fishkeeping should be to avoid this etc
. Personally i always under-stock my tanks since i see no need to stock my tanks to their limits, in the past i have had heavily stocked tanks however i did not appreciate my fish as much back then, and i think fish prefer having lots of space and freedom and stuff so now days i tend to understock my tanks in general (if i ever fully stock a tank then i make sure that the filtration of the tank is very good etc)
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ple overstock their tanks, do you and how do you keep them all happy if you do?
