Live Borders, the pool’s operator, closed the Mansfield Road pool on Wednesday evening due to an “unforeseen supplier issue” and it reopened just under 24 hours later.
Live Borders property manager Paul Cowan said the temporary closure was due to a nationwide shortage of CO2.
“Live Borders, along with many others, is affected by the shortage where the likes of hospitals are currently taking priority,” he said.
“We are working hard to resolve these issues and are also looking at alternate methods to ensure our pools are safe for the public and our staff.”
He said the Hawick facility has been the only one in the Borders to be caught out by the shortage so far.
The belated delivery of CO2 arrived on Thursday afternoon, allowing the pool to reopen in time for swimming lessons as normal from 3.45pm.
Mr Cowan added: “If deliveries of CO2 arrive as scheduled there shouldn’t be any more closures across our pools.
“We apologise to our members and other pool users affected by the closure and for the inconvenience that this may have caused.”
Swimmers were directed to other pools in Jedburgh, Kelso, Selkirk and Galashiels for the day. The gym was unaffected.
For further updates, go to www.liveborders.org.uk