We are almost at the end of the process of remodeling our pool. As part of the remodel, we replaced all the 40 year old equipment. This included changing the stainless Purex DE filter to a Triton II sand filter. This due to lower maintenance. I've decided to use both gravel and sand in the TR-140, however, I cannot find a place to buy the gravel. The Triton manual states the gravel should be 1/8" to 1/4" in size. Any suggestions of where to go? I've found the #20 Silica pool sand at HD.