i have a RR AGA 125 that im in the process of setting up and am having a hard time with bulkheads. I need 2 1 inch and 2 3/4 inch bulkheads. I went to lowes and they didnt have anything that said bulkhead(guessing thats an aquarium term) but they did have unions. My question is what am i looking for exactly. on the boxes at lowes it says 11/2-1...is that a like the 1inch bulkhead like im looking for??? If not wheres a noob place that i can get what i need haha