I have never had a tank with inside corner overflows. So my question, is there anything I need to be aware of? It has 2 one-inch holes in each side. One for draining to the sump, one is for a return. Do I use any special type bulkheads? ( Bulkhead 1" S x T Schedule 40 or Bulkhead 1" T x T Schedule 40 or one of each in each side?) Also, where do you guys get the nice color PVC parts?