Substrate for goby and pistol shrimp

[Gator_Bait]

To start things off, in the 10 years I've been in this hobby I've had shallow crushed coral sand bed, a 6 inch DSB, and Bare-bottom. I've had success with all and depending on your livestock all could be recommend in certain situations.

Here is my question:
I'm looking to set my 90 gal reef-tank up with my primary focus being a goby-pistol shrimp habitat (I like shrimp so I want to have as many as possible).
I was leaning toward a 1.5'' plenum with a 4'' substrate. Will the plenum be rendered useless by the activity cause by the shrimp and goby? If so, what is the best substrate to start with?

PS. I'm not new to this BB or others, I simply lost my password and I have changes email address. So, I had to start over again ;-(

Tanks Specs:
90 g
Wet/Dry
25 g sump
150 g aquatics systems skimmer (local company)
lots of LR (I will strive for 100 lbs)
lots of circulation
440 watts VHO (I'm considering doing two 150 watt MH, with 220 watts VHO)

[know-it-all]

my pistol will dig down the bottom of my substrate (2" of sand)
it seams to be pretty happy as long as the cave is under a rock.

as for a plenum, I would guess the srimp/goby would get deep enough to disturb it

[leveldrummer]

i think it would eventually get down to the plenum too, not sure if that would disturb the whole thing though, im not real familiar with how they work. but they usually stay under rocks and things. and they will dig out quite a bit and just push it where ever they feel is best.

i would just lay your rock work out, and go with a 2" SSB, that way they can travel where ever they want without you haveing to worry about it.

[Tim224DT]

In my 72 gallon i keep my gobie and a shrimp in a BB tank they seem to like it.


Tim

[Gator_Bait]

I want them to be able to have caves and such, but I'm not sure if DSB or DSB w/ plenum will result in a nitrate trap due to the sifting behavior. I think I might do a 4'' (Crush coral and Oocilte mix) then just add sand-sifters (jaw-fish, gobies, shrimp, snails, cukes, ...). I guess in this scenario, I will still need to vacume the substrate in addition to the water changes. I was hoping to avoid having to vacume the substrate.

[fish.freak]

you just need to make a layer they cant pass through, like plenum, xl large crushed coral 2" with a screen on top, followed by a sand bed of your choice