Thanks for the info but how small can of be AT LEAST cause I heard they grow HUGE and also i have a lamp I shine on them but it'd not like super bright and I face it more towards the wall and ibeas just wondering if the lamp on themes okay I heard that it can give them sizers and other people say only for 19 hours
Unfortunately, with goldfish there is so much mis-information out there it's scary. However, what you've been told by other members so far is not one of them. It all pretty simple really ... that little glass box they're in now just is not meant for goldfish and will not sustain them ... especially if it doesn't have adequate filtration. As the others have said, goldfish are messy fish with LARGE bioloads, so they will pollute their water with their own waste. It only gets worst as they grow .. and grow they will .. up to 8inches. But in a tank that small, I wouldn't worry about them reaching 8 inches, their growth will probably be stunted which means health problems.
This is one reason why a good rule for goldfish are 20gal for the 1st and 10gal each after that. You need that much water volume to handle their growth and their waste. A 30 gal should be the ideal minimum. If a 30gal is not an option, then get at the very least a 20gal tank ... it's not ideal but better than a 7 gal.
Then you need to look at adequate filtration so in a 20 gal / 30gal ... you need a filter that can handle a 55gal tank and at do 150gph at least .. preferably more. Unfortunately I don't think you can get any adequate filter for that tank.
Forget about how concerning with how long the light should be on. During the day keep you can keep it off and turn it on around mid afternoon till you go to sleep. To sustain them your talking about 50% PWC's once maybe twice a day, not to mention a good gravel cleaning. It can be done, but your looking at a lot of work to maintain clean water. Get a bottle of Seachem Prime (de-chlorinator) and an API test master kit ... they are great tools in this hobby.
As a final option you could always call up LFS's and tell them you have 2 fancy goldfish you would to re-home. Your certain to find one that will help.
EDIT - CORRECTION!! Opps
.. I just re-read and it's three goldfish? In that case FORGET about 30 gal ... you need a 40gal at minimum ... a thirty at this point wont work .. to much Bioload.