Sand bed

[albert_dao]

Originally Posted by Doug

Thats why I mentioned above to limit the rock and any thats used should be elevated. We once talked about doing an sps tank with only a couple of pieces of rock, elevated above the plenum on piles {pipe}, and having most of the sps pieces attached to the glass and overflow. Nothing wrong with then having some extra rock in the sump, as long as it can be kept clean.

The limited use of rock in the tank, will also help relieve caclium demand with the coralline. The 4-5in. of gravel will provide more than enough biological filtration.

Of course this limits types of fish, that require lots of hiding places & rock, like many of the smaller fish & dwarf angels, etc. Once the sps grows, more hidey spots are there. I know if I was a fish, this would not be my favorite habitat, at least not at the start.

:P

... I just don't like substrate.

There, I said it. LOL!

[DJKoop]

When I was planning on using the plenum way I was going to have a 3" bed using Caribsea Seafloor Special Grade Sand. 1-1.7 mm diameter grain. According to them

"This grade of aragonite is specifically engineered for plenum type nitrate reducing beds.

The pore water space created by precision grading also allows maximum pH support and dissolution of calcium carbonate."

[DJKoop]

Originally Posted by Doug

I would not use the powerhead method myself. Nothing wrong with the riser for allowing the removal of plenum water, {very slowly}, at times. But thats an alternative way and not from the original way Dr. Jaubert published.

The power head was just to get the bed activated. After awhile you remove the power head and the riser.

[albert_dao]

Originally Posted by DJKoop

When I was planning on using the plenum way I was going to have a 3" bed using Caribsea Seafloor Special Grade Sand. 1-1.7 mm diameter grain. According to them

"This grade of aragonite is specifically engineered for plenum type nitrate reducing beds.

The pore water space created by precision grading also allows maximum pH support and dissolution of calcium carbonate."

Before you make any sort of commitment, I'd ask around on RC and check how many people have long-term success with plenums in a reef tank.

On the other hand, if you're set on plenums, then you're set.

[andsoitgoes]

Albert - what are your thoughts on reducing a sandbed in an exisiting tank? I know there are spots behind my LR that I'll not be able to get at, but a LARGE portion is in the open and removable. If I was able to get this out each cleaning and left a small amount in the front, just to keep the tank bottom covered - would this be enough to rpevent the problems with a sand bed crash?

[DJKoop]

The only reason I have brought up the plenum line of things is Geothermal Aquaculture Research Foundation has lots of tanks and nearly all of them run with the plenum/sand bed and lots are over 5 years old and doing great. They do more research and fraging than anything else. I have found this place to be a great source of info. Fragging videos, and more. It's just that I've never heard of them ever having a problem and the tanks look absolutely amazing. I've never seen tanks stuffed so solid with corals before. And all growing like mad.

[Reefer Rob]

Check out these 2 articles by Toonen & Wee
An Experimental Comparison of Sandbed and Plenum-Based Systems. Part 1: Controlled lab dosing experiments
An Experimental Comparison of Sandbed and Plenum-Based Systems: Part 2: Live Animal Experiments

[DJKoop]

Very good reading and full of info, this is the most intersting paragraph

Overall death rates were roughly twice as high in aquaria with shallow sediments as in deep sediment treatments. The highest overall death rates were seen in aquaria with shallow coarse sediments over a plenum, and the lowest death rates occurred in aquaria with a sandbed composed of deep coarse sediments. The treatments that were closest to the design aquarists employ for deep sandbed, Miracle Mud and Jaubert plenum aquaria had intermediate death rates. The shallow coarse sediment design that is closest to that used in Berlin systems had one of the highest death rates, and the deep coarse sediment design for which there is currently no accepted name had the lowest overall mortality (Fig. 10). We did not test bare bottom tanks, but the data clearly suggest that the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare bottom tank!

[BCOrchidGuy]

WowOwowOwow... Cripes I had just pretty much almost for sure made up my mind for the most part to probably go bare bottom, now I'm kind of wishywashy.

Doug

[andresont]

[quote=DJKoop;233232]Very good reading and full of info, this is the most intersting paragraph

and the deep coarse sediment design for which there is currently no accepted name had the lowest overall mortality (Fig. 10). We did not test bare bottom tanks, but the data clearly suggest that the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare bottom tank!
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I see it diferently ie, coarse sand will only trap more CR*P and kreate more problems
JM2C worth