As I know about HydroCAD this is great!! It's simple and easy to get it right out of the box. Actually, the program is very intuitive and stable. I found HydroCAD which is very useful for me and I have yet to encounter a scenario. I used it for various place alike ponds, underground...
I think it's better to go through with the chemical lab and do the experiment with and expert.
Who will show you where your from the common assumption for biogas weight from water come from.
Because, I can not answer exactly what happened, so it's better to get an exact answer rather to...
No, as I know there is not any particular quantity which is specified as maximum limit.
However, if so , then please share what is the maximum limit.
Thanks!
magicrubbishclearanc