Raise tank bottom elevation

[badonkadonk]

I have a 20+ year old acrylic tank that is looking pretty ugly on the front and sides due to a deep sand bed I had the first 10 years that scratched up the bottom 3-4" where the sand was. When I went bare bottom I took the tank apart (the aragonite sand had become cemented, and I had to chip it into pieces to get it out of the braced top) and sanded/buffed the tank, but apparently didn't do a good enough job at the bottom where the sand was. Now the coralline has a foothold such that I can't clean it (think I further scratched it in the years I'd scrape the coralline and encrusting corals gone wild). So I can't see through the bottom 1/4 of the tank, and I've got a lot of corals on the bottom I'd LIKE to see. So I'm thinking of ways to make a "new", false bottom, raising it up to near the top of the coralline I can't remove. I don't want another deep sand bed (works ok the first years, then becomes problematic), though I'd actually like a shallow sand bed for my burrowing wrasses (they now have substrate in ceramic bowls that blend in pretty well with the live rock).

Any ideas on how to raise the bottom? I was thinking of a plenum on stilts (I see 6x6 modular plenums on Amazon, with iffy reviews - and not for this purpose) with a shallow sb, some inert material in the bottom (3" of marble? marble chips covered by plastic with fine holes to hold up a shallow sb), or something else? Sorry for all the blue in the image.

 

[Cell]

Starboard.

 

[MrGisonni]

Starboard is gonna be expensive for the whole tank bottom but is a legitimate option. How about a decorative molding on the cabinet to hide the coraline? I would worry about the water in the space under the false bottom going anoxic then accidentally releasing toxic amounts of sulfur and methane into the aquarium.

 

[badonkadonk]

Starboard.

Thanks, that got me on YouTube and pointed me to those white plastic cutting boards, which may be more cost effective since they are thicker.

 

[workhz]

Can you just hack up some chunks of dry or live rock and then cover with sand. Not sure if that constitutes a deep sand bed or not.
Or those bricks people use.

 

[badonkadonk]

Starboard is gonna be expensive for the whole tank bottom but is a legitimate option. How about a decorative molding on the cabinet to hide the coraline?

I'll think on that, thanks.

 

[badonkadonk]

Can you just hack up some chunks of dry or live rock and then cover with sand. Not sure if that constitutes a deep sand bed or not.
Or those bricks people use.

I thought about taking some of my old live rock and breaking it up, with some plastic mesh sheets over it to hold a shallow sand layer, but anything with spaces is going to collect detritus eventually I think and become a problem. Hence my looking at a plenum on stilts, with a large open space underneath that I can draw water from to keep it detritus free and aerobic under there.

The filter bricks could be good (though a bit costly too). They make any that aren't aluminum-based now? I had some about 10 years ago that negatively impacted my sps, I think, had super-high aluminum in my water on an ICP test.

 

[MrGisonni]

Best of both worlds??

 

[badonkadonk]

Yes, this looks very tempting... But it was the Brightwells I had before that had the aluminum, I'll look into the details and at other possible suppliers. Maybe put a layer of eggcrate over these (they get very friable/brittle, might help before putting down rock), then a couple/3 inches of sand. Thanks all.