Substrate madness

[Kellanved]

All right, so I'll be setting up a 75 planted sometime later this year (tank is currently sitting on my bed, just don't have room for it at the moment). The intention is to plant heavily through about much of the tank, and scape the rest. I was thinking it would look really cool to start with sand, and put a strip of sand across the front of the tank about 3inches towards the back. Then to place pieces of tall driftwood on either side, and use fluorite to create two mounds, obviously not symmetrical, but shaped to lift the plants, on either side of the tank, taking up most of the tank except a gully ( probably 2 or 3 inches wide, with slopes, not that you think i am going to try to create a wall) in the middle, and the back of the tank. Then to line this gully and the back of the tank with medium sized natural river rock in sort of a brown/tanish shade. Finally, i was thinking to use a third piece of driftwood as a sort of bridge over the gully.
So, the logic behind this was that i like the look of sand, but it is a bit of a pain to clean. I don't actually have to clean where the plants are, and that i would like to make this look natural. Thus by simply placing everything in this manner, and grading everything from finest to coarsest, i would be able to gravel vack the back, which is where in my experience most of the loam builds up anyway, have the sand i like to look at in the front, and still have healthy plants.
If any of this is completely retarded, tell me, and i will try something simpler, if you have any suggestions (for instance, i was thinking of hiding some pvc tubes in the mounds, with an open side to the back as hiding places, but wasn't sure how well that would work) I would be grateful.

sorry about the long post I'm a student, and rather used to writing papers.
Thanks

 

[Kellanved]

Hmmm, I was hoping someone would at least say that they didn't understand what i was saying. Give it one more try i guess.

 

[schaadrak]

Hmmm, I was hoping someone would at least say that they didn't understand what i was saying. Give it one more try i guess.

Okay.

I don't understand what you are saying. [j/k]

Do you mean you're going to slope the substrate from the front to the back and have sand be at the front/highest part and fade into the larger pebbles in the back? So that any mulm or detritus falls back off of the sand and onto the gravel, right? It sounds good, but the slope will level itself out after a little while and the sand will slowly mix into the gravel unless you have some sort of divider or retaining wall. The best way to keep your sandy area clean (besides vacuuming it and adding back any sand that you've lost) would be to direct a flow across it that would blow the crud off of it and onto the gravel.

 

[Kellanved]

All right, now i know what the problem is, and will do my best to post a picture to clarify. Thank you

 

[Kellanved]

Hope the attachment helps. I know it is very difficult to keep a sloped substrate, what i was hoping was that by completely planting the slight mounds, i would have a nice look, and that the roots of the plants would help maintain the shape.