You can definitely ferment in Lowe's buckets. In fact, I have been using them for fermenting for a few years now, ever since I started my brewing hobby. While they may not provide a perfect airtight seal, they do a decent job of keeping out unwanted bugs and stray yeast.
One thing to keep in mind is that during fermentation, carbon dioxide is produced as a byproduct. This CO2 creates a natural pressure inside the bucket, which helps to push out any oxygen and unwanted contaminants. So, even though the buckets may not seal as tightly as a fermenting vessel specifically designed for brewing, they still work effectively in keeping the fermentation process going in the right direction.
I have not encountered any major issues with using Lowe's buckets for fermentation. Of course, it is important to ensure that the buckets are properly cleaned and sanitized before use. This helps to minimize the risk of any potential off-flavors or contamination.
If you are concerned about the sealing ability of the bucket, you can always use a rubber gasket or a food-grade silicone sealant to create a tighter seal around the lid. This can help to further minimize the risk of any unwanted air or contaminants entering the fermenter.
In my experience, Lowe's buckets have been reliable and cost-effective options for fermentation vessels. They are readily available and durable enough to withstand the rigors of fermentation. Plus, their size is often convenient for larger batch sizes.
While they may not be the ideal choice for professional brewers or those seeking precise control over the fermentation environment, Lowe's buckets can certainly get the job done for homebrewers and hobbyists. They provide a practical and affordable option for fermenting your brews, as long as proper cleaning and sanitization practices are followed.