Indeed i don't mean to be a basher. However IMO that is unusally cruel of you to buy an arrowana that is already 7" and put him in a 55gal.,exspecially knowing ur wife wont let u upgrade past 110gal! i bought a 75 gal tank paid $60 USD for my silver 2 1/2 years ago and he was all of 5" and made it to near 9" when i said this tank is to small. A year ago i bought a 210gal specifically because he needed more room, now he is around 2 feet long, i do give you lots of credit for having friends that might take him in but it sounds to me like you have made an irresponsible decision my freind. Put in your shoes i would give him up once he hits over a foot in your 110. If however you cannot find him a home let me know i would be more than happy to donate you some money and room in my tank for him.