if its a hexagon, commonly 23" x 20" x 24"
exact measurements may vary slightly depending on the manufacturer due to glass thickness and whether they measure the inside of the tank or the outside of the tank.
a koi carp can grow as big as a pond
1 for like 5 months or so it will grow too big in about a year
In a 1500-gallon pond, koi can typically grow to be between 18 to 24 inches long, depending on factors such as the pond's environment, water quality, and the number of koi present. With optimal conditions and proper care, some koi may even reach sizes of up to 36 inches. It's essential to manage stocking levels and provide adequate filtration and aeration to support their growth.
Depends on how big they are, but you have to remeber they will grow big i would suggest no more then two. I have 2 in mine right now and they are fine with that but they are still 6inchs once they reach 20'' they probable wont enjoy that much and might slow there growth.
they grow bigg around 12 inches
A young koi is about 3-7 inches. when they grow to adulthood, they can as long as 40 inches!
Koi can live for hundreds of years in that period of time they will grow 3 ft. it just takes them a while to get there.
It kinda matters. Mostly 25 inches, or more.
That depends on if you fit the fish to the tank, or fit the tank to the fish. Koi will grow to the size of the tank. The bigger the tank, the bigger they will grow. You can put about 6 4 inch Koi in a 30 gallon tank. And of course, the bigger the fish, you need to adjust your tank size. The koi will quickly outgrow your tank! They will be like prisoners in a cell, not able to move around. Probably enough to survive if you keep up the waterchanges, but not enough to thrive. Koi belong in a pond.
To the best of my knowledge Koi do not need salt in their water under normal circumstances, so I would be advising that any potable water would be perfectly OK for Koi.
The best kind of pond pump for a two hundred gallon koi pond is an alpine pond pump. This would work best for this size pond because of it's size and power.
It depends how big your Koi is and how big the Catfish is. If the catfish can fit in the Koi's mouth than it will get eaten.