why would you think a 20 gal would help? personally i don't see the advantage there. they are hard to keep clean and take a lot a of maintence. also 2o gal is the minimum for just 1 rat, having 2 in there would be too much. the only time tanks are approiate is when you have a nursing mom with pinkies or tiny babies. and the only reason to use them then is because its safest for tiny babies, they can't roll out of the bars and are protected best from drafts.
if you need help socializing your rats there are other tricks to try. if you are located in a colder place right now letting them ride in a hoodie pouch or hood while your home helps. or laying on the couch with a blanket tucked around you, put the rats between you and the blanket and watch tv or read a book.
if you are finding it hard to interact with them because of time constrants find ways around it. if you're home and not cooking or cleaning then let them ride on your shoulder. when you have down time bring them to the couch or chair with you for it. if you can keep them with you for a minimum of 20 mins at a time they will start to fear you less and less as a rat can only maintain the feeling of fear for 20 mins.
treats are always good to have on hand to offer to them as well. don't be surprised if they won't take from your hand right away but if you offer enough they will catch on. just leave the treats in front of them if they don't take from your hand but offer it from the hand first each time. if you can find something they really love that will make it easier.
the final suggestion i have is to take to them. use their names often and touch them, pat them, tickle them, generally interact as muc as you can with them. as they get used to your smell and voice and learn that you are not there to harm them they will come round and let themselves love you and become more confident. all this will take some time and a good deal of patience but its doable and very rewarding.
good luck and please keep us updated on their progress.
