This is my first sub panel and my electrician is in the hospital and I can wait no more. I'm in the process of wiring up a 60a sub panel from my 100 amp main. I will be running one 40A 240 circuit and one 20a 120 circuit. My run is 75 feet. I ran #6 thwn in schedule 40 18 inches deep. the ground And neutral are 10awg. I know the ground is ok but questions are arising about the neutral. I had three people( place I bought wire from, home depot electrical guy, one electrician). I go and see my guy in the hospital and he says no go on the 10awg neutral. I ran two 8 foot ground rods 7 feet apart. my neutral is isolated from my ground at the sub. I've searched and searched and some say yes up two sizes is ok and others say no at least 8awg. all my wire has been pulled and secured in sub just have not physically hooked her up at the main. The job is not being inspected but I've done everything else to code so why skimp now. should I use the 10awg as a fish and pull something heavier for my run or am I safe? the 40amp is powering ballasts. the 120 is powering fans and pumps. sorry for the long read I'm just stumped. thank you to all with the knowledge I seek.