A mandy should be making a successful 'kill' of a pod every 5 seconds to remain healthy. Keeping one in a well-established 50 with 50 lbs of holey rock, and a mature, year-old 20 gallon fuge with another 20 lbs of rock is very marginal. If you meet those conditions and there is no competition for pods, you can do it with caution.
To run the math, there are 86400 seconds in 24 hours...and given 12 hours of dark when it is not eating (it actually eats before the lights come on...that is 43200 seconds of daylight, divided by 5 (every five seconds)---meaning that a mandy eats about 8640 pods a day, or 720 an hour. Two thousand pods, if fed to it in the required concentration, will be eaten in less than 3 hours. If you have a pair---do the math. You need at least 100 gallons supported by a very large, strong fuge with cheato and live rock.
Note that mandarins and scooters are the one type (dragonets) exempt from quarantine, You take your chances, this once. Their difficult diet makes quarantine a no-go: fortunately their extreme protective slime coat does not allow them to host the ich parasite (unless the fish is sick and/or in bad water conditions [particularly very low alkalinity.]) IE, they can get it, but it is very, very rare. Their slime coat is so thick they feel like a handful of warm Jell-o, and they are frequently believed to have ich---when they have simply gotten some white sand grains stuck to the slime coat.
They have no sense of territoriality toward other species (and will violate territory completely oblivious to the other fish's objections.) They will, however, kill ANY other mandarin that appears if the hunting is not very, very, very good. If you do not start out with a mated pair, don't try to put another mandy in later.
If you have the right tank and are willing to risk the no-quarantine dice roll on a pretty solid bet---they're a very pretty addition to your tank, usually out even before the lights are on, terrorizing the pod population.
To run the math, there are 86400 seconds in 24 hours...and given 12 hours of dark when it is not eating (it actually eats before the lights come on...that is 43200 seconds of daylight, divided by 5 (every five seconds)---meaning that a mandy eats about 8640 pods a day, or 720 an hour. Two thousand pods, if fed to it in the required concentration, will be eaten in less than 3 hours. If you have a pair---do the math. You need at least 100 gallons supported by a very large, strong fuge with cheato and live rock.
Note that mandarins and scooters are the one type (dragonets) exempt from quarantine, You take your chances, this once. Their difficult diet makes quarantine a no-go: fortunately their extreme protective slime coat does not allow them to host the ich parasite (unless the fish is sick and/or in bad water conditions [particularly very low alkalinity.]) IE, they can get it, but it is very, very rare. Their slime coat is so thick they feel like a handful of warm Jell-o, and they are frequently believed to have ich---when they have simply gotten some white sand grains stuck to the slime coat.
They have no sense of territoriality toward other species (and will violate territory completely oblivious to the other fish's objections.) They will, however, kill ANY other mandarin that appears if the hunting is not very, very, very good. If you do not start out with a mated pair, don't try to put another mandy in later.
If you have the right tank and are willing to risk the no-quarantine dice roll on a pretty solid bet---they're a very pretty addition to your tank, usually out even before the lights are on, terrorizing the pod population.