I would highly recommend it, yes
1-4 crabs need a 10-gallon tank and 5-8 need a 20-gallon tank and 9-12 need a 25-gallon tank thanks,mickey
This depends on the strength of the filtration system on the tank. On a 'normal' five gallon tank (filter turnover about 5x/hour) three or four would be a good number. On a 'five gallon tank on steroids' (I have one of these - filter turnover 12x/hour) I kept seven with no problems. If you're going to keep more than three or four, regardless of your filtration, you need to be religious about tank maintenance - 50% water change, every week. Keeping more than 6 or 7 in the tank is probably not going to work. (For filter turnover, 5x/hour means the filter pumps 5 times the tank's volume each hour, so that would be a 25gph filter in a 5 gal tank.)
A simple air driven corner filter should do the job in a tiny 5 gallon tank provided the tank contains no more than 3 guppies. The first basic rule is :- 1 inch of fish needs a minimum of 1 gallon of water. Your tank is nominally a 5 gallon tank which means when it is only filled to within an inch of the top and has gravel on the bottom, the most it will be holding will be around 3.5 to 4 gallons of water.
You can put it on a table if you choose. NEVER put a tank on the floor.
Some say they need a 5 gallon tank, but a 1 gallon tank should be ok if they are by theirselves.
If the temperature is around 20 degrees (Celcius) probably not. But for a five GALLON fish tank, probably.
If you look after the tank properly it should only need a major "cleaning out" once a year or so. To do this, you need to follow the basic rules of fishkeeping which are. :- 1 inch of fish needs at least 1 gallon of water. Every tank must have a permanently running 'cycled' filter. :- Every tank must have at least 50% of its water replaced every week.
A well set up and properly filtered 30 gallon tank would be OK.
you can put a betta in a 5 gallon tank
If you are referring to Air pumped from an "aerator' Then the answer is "none". A filter is needed not an air pump.
Yes about one fire bellied newt can fit in the tank with no promblem get a small filter and a dock of some kind and decor if you want.
They need a 5+ Gallon tank and you can only have one in the same tank.