If you are trying to do a nitrogen cycle, do not use that product. It will not aid your cycle of the tank. Many of such products have the wrong type of land based bacteria which will die in the water after just a week, and your seemly completed cycle will crash in that moment.
You need to do a fishless nitrogen cycle. It will grow the correct type of water based bacteria to take care of your fish's ammonia.
It is said 1 inch of fish per square inch of SURFACE area of the tank. More than this can overload the bio load of your tank and cause a reset in its cycle.
How much gravel for 200 gallon tank
A betta fish would be much more suited to a 1 gallon tank than a 'variety'. You shouldn't keep much more than one fish per gallon anyway.
a gallon
depends on where you buy it from
find an empty gallon of milk bottle. There you are.
Fish Oil has a specific gravity of .92. Therefore, if a gallon of water weighs 8.64 lbs, standardized fish oil weighs 7.69 lbs.
5 gallon
A 55 gallon fish tank will be able to give rise to thousands of fish.
Exactly 30 US gallon.
a gallon is much too much, a standard fish can fill a regular and average glass bowl, a gallon! Totally enough, I tell ya, you, the questioner.
That all depends on how big the fish are. The rule is "1 inch of fish needs a minimum of 1 gallon of water". The tank could easilly be overcrowded if it is stocked with large cichlids and understocked (if there is such a thing) if the fish are Neon Tetras.