As far as i can tell yes it should be cycled i test the water regularly and havent seen any problems till now i also have the 10 gL which is my daughersnow with 3 guppies and 6 baby blk mollys yes i knw i have to find them a home when they grow bigger i had to adults and found them mateing then babies adults habe a new home now but like i said the shark is the only sick fish i have had and have had her about 7 mo. Now she started in the 10 gal and when i got the new tank icycled her water into the new tank and left some for my daugjters new fish (just added more new water to both to fill up.