ROSS GIBLIN/Dominion Post
The emperor penguin was continuing to do well and was putting on weight, Wellington Zoo spokeswoman Kate Baker said.
"He now weighs 23kg and has gained 1kg since the sand was removed,'' she said.
Since his arrival in Wellington, Happy Feet had board and lodging in an air-conditioned private room at the Zoo's hospital The Nest.
In the next couple of days the zoo hoped to make life a little bit more exciting for the lonely bird.
"You can compare him in his enclosure to someone in hospital in terms of boredom,'' Ms Baker said.
The zoo was now working on cooling down its saltwater pool enough to give Happy Feet a playground in his preferred temperature.
The move to the pool house would not only mean more exercise and variety for the penguin but might give the public a chance to get a glimpse of the adventurous bird.
So far his fans can watch him eating, sleeping and walking through an online live-stream on TV3's homepage.
"If he would swim in the saltwater pool the public will be able to watch,'' Ms Baker said.
The juvenile bird won global fame when he turned up on Peka Peka beach, north of Wellington, three weeks ago. The penguin since had various procedures to remove sand, sticks and rocks from his stomach.
Providing Happy Feet made a full recovery, he was set to be released into the Southern Ocean to find his way back to his home in Antarctica.
Although he was packing on the kilos, feasting on up to 2kg of salmon a day, his weight was not the only indicator for his travel-readiness.
It rather depended on his body condition, so there was no definite weight that he needed to reach and when he might be ready to leave, Ms Baker said.
Happy Feet was only the second emperor penguin known to have landed in New Zealand. The first was found in 1967 at Southland's Oreti Beach.