It is highly suggested that you work with a social media tool. Consider for a moment that you could be on 4 different platforms & posting manually on each of them several times a day. That would be a lot to manage and all of this on top of actually overseeing your small business. All you’ll possibly do is publish, and nothing more productive.
Try to automate as much of the activity as possible. For example, schedule your social media updates ahead of the time. Use social media scheduling tools like @SocialPilot @hootsuite or @apphi to auto-post your updates to all your social accounts then evaluate the results with the analytics they provide.