The red alert warning for Lake Ainsworth has been lifted by Ballina Shire Council.
The move follows two consecutive weekly results below red alert levels.
Following a red alert, Council must have two consecutive tests a week apart below red alert level before the site can be reopened.
A Council spokesperson said Lake Ainsworth is now at green alert, with no visible scums, and there are no longer any restrictions on recreational activities.
Blue-green algae occur naturally and can reproduce quickly in favourable conditions where there is still or slow-flowing water, abundant sunlight and sufficient levels of nutrients.
Council says it will continue to monitor the algae levels as there is a risk of another bloom occurring due to the recent red alert and current weather conditions.
The algae status of Lake Ainsworth is updated weekly on the Council’s website ballina.nsw.gov.au