Sand bed

albert_dao · #1 01-30-2007, 06:15 PM

Quote:

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 · #2 01-30-2007, 07:31 PM

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 · #3 01-31-2007, 01:52 AM

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 · #4 01-31-2007, 01:59 AM

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 · #5 01-31-2007, 02:30 AM

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 · #6 01-31-2007, 03:08 AM

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 · #7 01-31-2007, 03:54 AM

[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!
******************
I see it diferently ie, coarse sand will only trap more CR*P and kreate more problems
JM2C worth

albert_dao · #8 01-31-2007, 05:08 AM

Hold your horses folks, let's take into consideration a few facts here and their relevance to these articles:

a. These were temporary, short term installations. Hardly set up for stability. They were not cycled properly and the actual equipment selection was unrealistic. Did anyone else notice the lack of massive flow, skimmers, cured live rock, etc?

b. The fundamentals of reef keeping are quality equipments, a good knowledge base, and routine maintanance. These procedures allow one to keep up with the dynamics of reef chemistry, organic cycles.

c. Sandbeds/plenums are a nightmare for maintanance. That's pretty self explanatory. Long-term results on properly set up (equipment, cycling, stocking, etc) BB tanks are numerically superior to those of DSB/plenum orientated strategies, IME.

For real guys, look at those experiments. Who in here has a tank that even remotely resembles those tanks (either in appearance or mechanics)?

*cough cough*

Reefer Rob · #9 01-31-2007, 05:11 AM

I don't think the death rates in their experiments would apply to an established tank; other factors would come into play in a newly set up tank.

The thing I found most interesting is that all tanks experienced a similar level of nitrate reduction- shallow or deep substrate.

It made me re-think the value of plenums and DSBs. I fact it should make us question what we think we know about how nitrates are reduced in our aquariums. Nitrate is obviously being reduced in areas other than anoxic zones

albert_dao · #10 01-31-2007, 05:18 AM

Quote:

Originally Posted by 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.

That's all in the eye of the beholder. See what the Europeans think of the GARF tanks and... Well, no, ask for yourself:

http://www.reefitalia.net/forums/index.php?

There's a few over there who speak English.

In contrast:

http://reefcentral.com/forums/showth...hreadid=971190

As far as I can tell, none of those tanks incorporate plenums and most use some form of probiotic (prodibio, zeovit, etc) or chemical filtration (carbon, phosphate reactors, etc) to keep their tanks low nutrient. Those methods are philosophically antithetic to those of DSB/plenum flavor; however, they will support substrate.

Anyway, like I said, it's all subjective. I'm sure the GARF method works, but they have access to live substrate. That's a pretty BIG advantage over us folks here.

As far as their knowledge base and experience goes, well, my opinion is beyond the scope of this post, but you'll find some pretty mixed reviews over on RC.

Drat, I should be doing homework, LOL!