I see a lot of noise and fireflies with Glass BSDF Shader I made a cube in Blender. The cube has BSDF Glass shader. When I render it there is a lot of noise and fireflies.

I tried everything: Change clamp, change light bounce, denoising, glossy filter, more samples... just everything. I don't know what to do now. When I removed the cube there wasn't noise. The light is point light and in the center of the cube. Blender 2.81 Beta, Cycles.

https://imgur.com/a/BQhwXDL
Glass is something that causes a lot of noise in a cycles. While the proper solution is lots of samples, there are some options to get quicker acceptable results.

The first option added to 2.79 is Denoising

2.81 adds a new denoise composite node that uses Intels Open Image Denoise. CGCookie has a look and comparison.

There are also third party addons such as D-Noise.