Do yourself a favour: go back to your previous question and read what I said there yesterday:
How do I save these data in db[
^]
With the exception of the "trailing comma" you have ignored all of it.
So a summary of the points you have already been given:
1) Never do "anonymous inserts"
2) You almost certainly shouldn't be inserting ID values
3) You need to specify a value for each of the parameters in your INSERT statement
4) The parameter names must match up in the AddWithValue call and the INSERT statement
You need to fix these things!
And now the continuation of "how not to do INSERT". :sigh:
What on earth do you expect SQL to do with "Water_Level" as a parameter? You don't even try to refer to it in the INSERT statement so it has no idea at all that it should even look for a parameter of that name.
Where are the textbox values supposed to go? You're giving them all the same "parameter name"!
If you want to add multiple textboxes to your row, you need to list them as different parameter names, and refer to them as such in your INSERT statement.
Stop guessing. Start thinking, and stop ignoring what we say in the hope that you know better so it it'll all work out in the end if you just guess some more! It won't...