My life has taken me in a much different direction than I ever could have thought and I'm just too busy for my 4 saltwater tanks. I'm keeping everything and going to combine to 2. I miss having a freshwater tank and my roomate wants one as well so were throwing one together for a low maintenance tank. My questions are it is drilled. I have loc line. A mag. Etc. ( it's currently not plumbed ) should I plumb it, or just PVC from the bulk heads up and cap them? Going to do a hob penguin. Is sand harder than just the typical gravel rocks? Also so you see any point to wait to add the fish or how long should I wait?