Our high quality black vinyl tubing is preferred for use in garden ponds and ornamental ponds. The black color blends in with the bottom and also inhibits algae growth inside the pipe. (Clear vinyl tubing allows for algae growth which can build up and reduce water flow.) Ideal for use with water or air. 3/8" - 1/2" tubing has 1/16" wall; 5/8" and 1" have 1/8" wall thickness.