New Zealand's Corrections Department revealed last month that Tarrant was segregated from other prisoners and able to be observed constantly, either directly by staff via CCTV camera.
Tarrant has been moved to New Zealand's only maximum-security prison in Auckland and will appear at the Christchurch High Court through a video link at 10 a.m. (2100 GMT Thursday).
Tarrant, 28, was charged with 50 counts of murder and 39 counts of attempted murder.
Tarrant was then remanded in custody.
Thousands of visitors to the reopened Al Noor mosque, where 42 people were killed, have offered condolences and sought to learn more about Islam, said Israfil Hossain, who recites the daily call to prayer there.
Friday's court date was the second court appearance for Tarrant.
The gunman was armed with semi-automatic weapons and broadcast his attack live on Facebook.
Services were also held in several other New Zealand cities.
Tarrant did not address the court.
In a minute issued to media he said he had taken into account a number of factors in reaching his decision, including the need to preserve the integrity of the trial, the role of the media, and the court's obligations to the victims of the massacre.
Austrian authorities say Tarrant also donated 1,500 euros ($2,200) to Generation Identity's sister organization, the Identitarian Movement of Austria.
"It seems he don't care what has been done".
"At the moment, if someone commits a crime against someone who is gay, or due to their religion, that's recorded as an assault or a homicide", said Janet Anderson-Bidois, legal manager for the Human Rights Commission, adding that the organisation has called on the government to record hate crimes for years.
"I needed to see how he feels". He has said he wants to represent himself. Sorry for my friends who have been killed.
Prime Minister Jacinda Ardern described the massacre, the worst mass shooting in New Zealand, as a "terrorist attack" and some legal experts thought it could result in charges under New Zealand's terrorism laws.