Hi, how to install a septic riser?

Hi folks – I had a blockage from my house to my septic system. I just cleared it with a 50 foot ½ inch Mini-Rooter drain snake. I used the Arrowhead attachment to bore through the blockage. But my question is “how much standing water should you see in the sewer line cleanouts?” Here is why I am asking. I have a cleanout in the basement floor and another cleanout close to the septic tank about 40 feet away from that cleanout in the basement floor. When I had the blockage the cleanout in the basement floor was full of water, maybe 3-4 inches below the floor level. However, the cleanout near the septic tank had no standing water at all. My understanding is that if the cleanout near the septic tank has no backup, then you know that water is not making it to the septic tank and so the blockage is in between the house and the septic tank. So following that logic I rented the drain snake, and lo and behold, using the drain snake on the cleanout in the basement floor I was in fact able to clear the blockage. I flush toilets and everything drains fine. Before that the toilet in the basement and the cleanout in the basement would overflow with sewage. After snaking now I see only about ¾-1 inch of water standing in the cleanout in the basement floor whereas before I snaked it was about 8 inches. And now, unlike before, I do in fact see some water standing in the cleanout near the septic tank (I can’t tell the depth of the water there, unless I drop a weight on a string or something like that.) So are you always supposed to see a little standing water in all cleanouts, or only some cleanouts? I’m not clear on what you should see. Also, is there a really good test to see if the drainage is working properly other than just flushing some toilets? Any thoughts would be greatly appreciated!