Advice on New Sand...Possible Plenum?

[JonezNReef]

I am planning on adding sand to my refugium, a deep sand bed(possibly a plenum) in my sump that isn't lite an serves as a cryptic zone and a shallow sand bed to my DT.
The question is will my tank cycle again from this? Is there anything I should watch out for? Should I use one size or multiple sizes of sand? Should I add all the substrate over a period of time?

I was planning on having different size substrate in my DSB starting with rock rubble, then crushed coral (calcium reactor media), then Fla crushed Coral, and finally Aragonite sand. I was wanting to do different size substrate layers to allow water to flow easily through the sand. I also was considering a plenum under the sand bed as well. I was wondering if anyone has any experience with a plenum at all and what the pros and cons where in your experience?
I have read about them and have read some of the pros and cons but would like to hear someones first had experience with one.
As for the the other sand beds I want a decent sand bed in the fuge for pods and what not. Also I want a shallow sand bed in the DT because I don't care for the look of a BB tank and it bothers me more than I thought it would. Ive liked how easy it is to clean without sand but think it will look better with it. Not sure if it would really serve a function other than looks though as far as my DT goes.

Please any and all thoughts,ideas and experience will be appreciated

[JonezNReef]

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