Thanks for all the helpful tips.
I also spoke to someone at my local Big Als and he recommended the PVC
as well. I really liked the suggestion about covering it in the same substrate as is in the tank. I will probably go in that direction.
The Pleco is probably getting too big for the 55 gallon but my wife kind of loves him and will not let me get rid of him. I have not measured him but my tank is 12W x 48L x 21H and he almost touches the front and back glass. I estimate he is 10 or 11" long.
My sister and brother in law are installing much larger tank in their house and if they go Freshwater I might move him to their place. I think their tank is going to be in the 250 gallon range as it is being custom built to fit inside a wall in their rec room.