I'd recommend defining what type of art you are seeking to find on Instagram. For example, optical art is a specific type of art. After some searching on Instagram, I was able to find #opart, which focuses on this particular type of artwork.

To become more noticed on Instagram, I'd recommend finding a niche. Instead of creating an Instagram account about art, a better strategy would be to create an account about a specific type of art such as optical illusion artwork.

The more specific you are about your niche, the better you are positioned to grow on the Instagram platform.