I got to give Albert Theil credit for publishing a lot of reef books way back when. By the standards of the time, they provided a lot of good information.
That being said, by today's standards, there is a lot of obsolete information in them. If anyone it interested in them, you can get the books used on Amazon for next to nothing. There is still some good information in them.
I disagree with with quite a bit of the previous post.
First off, your tank is not a marsh. It's a carefully constructed artificial environment. It also is going to have a massive amount of livestock for a given area. Unless you want to devote space to a massive refugium in relation to the display tank, it is very difficult to get a sandbed to do everything a salt march does.
This means the sandbed is going to accumulate a lot of unwanted material and you usually need to clean it from time to time. My own tank it about due for this, maybe I'll get to it in a few months (grin).
I have never had a problem with spiking any of the usual water parameters. When I did run a controller or ORP meter, I would see an increase in ORP. This was because I removed a lot of dirt and other bad stuff as part of the cleaning. I'm not trying to get all the dirt, just the worst of it. Even with my fairly shallow sandbed, I'm only going into the top layer about 3/4".
I tend to think that people that do see a spike in water parameters are going it wrong and being much too aggressive with their cleaning.
My experience with vacuuming the sandbed is quite a bit different, and I would recommend doing it from time to time. Yes, I know this isn't what you feel Albert Theil told you.