Reunite With My Shark?

[XxTbaggerxX]

A couple of months ago I had a 5 gallon tank with a red tailed shrark. When I first bought him the person that I bought him from didnt say anything about him being aggressive from lack of space, ect. So eventually he got so aggressive that he started to starve most of my fish in the tank. My friend's dad has a 55 gallon tank and so I handed him over to the dad. Now I just recently bought a 20 gallon and Im thinking about taking him back and putting him in it. I dont know if its good for him or not.
*Dads tank
1. The dad's tank is overvrouded (arond 30-40 fish, most guuppies, 3 sharks)
2. After a while in his new tank he got white bruses or spots (probably getting hit?)
3. Only about 6 cm of gravel and filthy

But Im wondering that if I put him back into my new tank that he will still not have enough space to feel comfortable. What should I do?

 

[seb_negrete]

20G would still be pretty small for a RTBS. i can't imagine how cramped he must have been in a 5G! what other fish are going in your tank?

 

[smurfyy_2k3]

*Dads tank
1. The dad's tank is overvrouded (arond 30-40 fish, most guuppies, 3 sharks)
2. After a while in his new tank he got white bruses or spots (probably getting hit?)
3. Only about 6 cm of gravel and filthy

judging by these conditions it might be nicer for you to take him back