Don,

Here is a rotary vane compressor that we offer that produces enough volume for 4 diffusers:

http://www.livingwateraeration.com/rv75.html

If you want a larger unit here is a link to the 1 HP:

http://www.livingwateraeration.com/rv100.html

I think you will find that we have very competitive prices on these compressors. Also if you have not purchased the vertex diffusers we have rubber membrane diffusers that are very comparable and again our prices are competitive. There is no reason that our diffusers will not operate just as good or better then Vertex.

http://www.livingwateraeration.com/aeration-accessories-air-diffusers.html

I hope this helps, please let me know if you have any questions.

thanks,

Daniel


Daniel Crackower
Living Water Aeration