Blueprint For Building A Sand Rail Can I Use Building ( For Cement ) Or Road Constuction Sand To Make A Sand Bio Water Filter.?

Can I use building ( for cement ) or road constuction sand to make a sand bio water filter.? - blueprint for building a sand rail

I make my boat as self-sufficient as possible.
I wonder what I need to sand to clean the rainwater.
I have the plans, read the results of the investigation (chemical analysis).
It should work smoothly and to be sure, but I'm happy about the right size of grain affected
for sand.