Why can't I get a clean result from cycles? In 2.79, I could get easily acceptable quality from the native renderer. I'd like to move to 2.80 but can't get a good quality render from cycles and eevee is far worse. 

The files below are an old practice image that used many of the basic techniques that I needed to practice. I'm more interested in technical drawings but needed something a bit more capable than the free Sketchup offered. 

http://www.bcae1.com/temp/blender%20help/

Can I get a clean render (no fireflies?), proper clear transparencies, clean reflections in cycles? In blender render, it was so simple. In cycles, I'm having no luck. 

To make it easier to show new settings:
http://www.bcae1.com/temp/blender%20help/hydrauliccylindertransparenttube01.blend

This will allow anyone helping to change the materials for the tube without having to try to go through the mess I have on the larger file. 

Thanks to all who posted. 

I think, for now, I've found a solution that will work for me (Radeon ProRender). The controls work as I expect. I'm sure that Cycles works as well or better since I've heard very little about the Radeon renderer but I can make ProRender do what I need it to do for now where Cycles just baffles me. Thanks again.
Either crank up your samples or try denoising with AI or Photoshop / AfterEffects.
The former takes a little longer to render, the latter produces artifacts at times.

I am not too sure about the current implementation of denoising into cycles, but there is an addon called dnoise you could try out. Otherwise go into the "Properties" Editor, into the "Render" Context and and put a higher value into the "Render" textfield under "Sampling".

The thing is, that Cycles does a lot more realistic calculations than BlenderRenderer ever did, so it takes longer to produce a clean result...