Substrates and sand beds

[Acolin]

Substrates and sand beds
Perhaps the reason that so many folklore controversies exist in this hobby is due to the paucity of exact experiments relevant specifically to hobbyists. In a test of 8 tanks, with or without coarse or fine sand, with either deep or shallow sand depth, and either with or without a dead water plenum underneath:

“There is no difference among the final concentrations of any nitrogenous waste in tanks with or without a plenum. Likewise sediment depth had little overall effect on the ultimate values for water parameters in any of the experimental treatments (Fig. 8). The greatest effect observed in this experiment was on parameters associated with the buffering capacity of sediments in the mean particle size trials rather than nitrogenous waste processing capacity (Fig. 9).

Our experiment shows no evidence for any of the espoused benefits of a plenum (reviewed by Goemans 1999). Instead our results suggest that any benefits seen are a direct consequence of the presence of the sediments themselves rather than the void space beneath it.

We show that even among identical tanks set up in a laboratory without any live animals, there can be dramatic differences in performance from one aquarium to the next (see Figures 2 & 3 above). Our results highlight the problem with any study lacking proper replication, and in which there are no controls. We argue that anecdotal evidence is simply presentation of an opinion in cases such as this, and more than 5 years of heated debate has resulted from the staunch defense of these opinions.”

The significant differences among the experimental treatments were almost entirely in the buffering capacity of the sediments rather than the biological breakdown of nitrogenous waste products. The largest differences among the treatments were seen in the final concentration of phosphate: coarse sediment treatments had roughly 17 times the final concentration of aquaria in fine particle treatments!

However!
Actual fish deaths in aquariums with no plenum and a deep coarse sand bed were half as much those with a plenum and shallow, coarse sand (part 2)!

…deep, coarse (27.41 mg / L ± 6.89 SE) and shallow, fine (20.42 mg / L ± 6.89 SE) sediments have the highest average final nitrate concentration…

Our results suggest that stocking level of the aquarium, and any animal deaths, have a much greater effect on the overall water quality than the specific design of the aquarium set-up you chose to follow.

The only significant effect was that death rate in shallow sediments was significantly higher than (almost twice) that of tanks with deep sediments (Fig. 9), and the highest death rate of all was observed in aquaria with shallow, coarse sediments over a plenum (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!

http://www.advancedaquarist.com/2007/5/

http://www.advancedaquarist.com/2005...20Plenum-Based

[WarDaddy]

Just glancing at that study it appears to have been a 118 day experiment. That is not a long enough time to see the benefits of anything. The initial cycling of the tank is just concluding at 90 days...and 90 days is no where near enough time to get a deep sand bed or plenum to seed and populate itself.

I think that to get a good feel for how those different sand beds preform 12 months is a better experiment.

[mflamb]

Originally posted by WarDaddy
Just glancing at that study it appears to have been a 118 day experiment. That is not a long enough time to see the benefits of anything. The initial cycling of the tank is just concluding at 90 days...and 90 days is no where near enough time to get a deep sand bed or plenum to seed and populate itself.

I think that to get a good feel for how those different sand beds preform 12 months is a better experiment.

Short term experiments for short minded aquarists. If you are in for the short term, do whatever you want, and kill everything you buy...people do it everyday. That's why John and Marcye are so picky about who they sell to and what they sell. Don't be a sucker and believe everything you read. Output is skewed by input. Design and build your reef for the long term with proven techniques. There will always be new ways that will be proven over time to either work or not. In the mean time, I'm not setting up an experiment, I'm setting up a reef to keep LIVESTOCK ALIVE!!!

[Acolin]

good pt.
so we should watch for part 3...

[Acolin]

"Design and build your reef for the long term with proven techniques."

so where are the proven techniques for the long term with sand beds? I agree that a 6-month old system is still young, but where are the studies for ones older than that?

the study shows that results can vary widely with each aquarium! so what is proven and what is merely anecdotal?

[ichthyman]

LOL Welcome to nearly two years ago, that article was from July 2005. I'm breaking out the popcorn in hopes of reading part 3 so I can stop killing my livestock. :|

[WarDaddy]

lol

[mflamb]

Originally posted by Acolin
"Design and build your reef for the long term with proven techniques."

so where are the proven techniques for the long term with sand beds? I agree that a 6-month old system is still young, but where are the studies for ones older than that?

the study shows that results can vary widely with each aquarium! so what is proven and what is merely anecdotal?

The proof is in the pudding. It doesn't have to be a "written about study" to prove that it works. You might check out the multiple thousands of aquariums out there housing millions of coral and fish for multiple years. If you remember, just a couple weeks ago, we talked about sand beds and how each system has its limitations, and if "operated" within their limits, then success could be had. This isn't speculation. This is what people are doing everyday, and have been doing for years.

[Acolin]

yes, the club diuscussion is why I looked up the articles and posted this, because the measurable results can be so varied! I thought deep sand beds would have excellent nitrate levels but the study says that is not so in the short run!

[triggerfish1976]

Acolin,

Get with the times. Don't you know that DSB's, plenum or not are so 2006. The latest trend is the so called "RC Experts" method. It will incorporate live rock, under gravel filter, wet dry filter, 10" DSB with a plenum under 1/2 of the tank, undersized protein skimmer, ozone, UV, carbon, filter socks, refugium and zeovit.

[chrismhaase]

speaking of the presentation, have those notes been published? Bryan?

[mflamb]

Originally posted by triggerfish1976
Acolin,

Get with the times. Don't you know that DSB's, plenum or not are so 2006. The latest trend is the so called "RC Experts" method. It will incorporate live rock, under gravel filter, wet dry filter, 10" DSB with a plenum under 1/2 of the tank, undersized protein skimmer, ozone, UV, carbon, filter socks, refugium and zeovit.

I think I'll try this one!!!

[WarDaddy]

Originally posted by chrismhaase
speaking of the presentation, have those notes been published? Bryan?

I can't Publish what I don't have :-)

Just waiting for their notes so we can get them posted

[mflamb]

Hey...I have mine and Paul's. I need to summarize what Jason said about BB. He didn't bring notes. Seriously, he's an expert on the subject.

[DaddyJax]

Thanks but I don't know if I am an expert on anything! I use BB and love it and did alot of research on them before going BB and tried the DSB and SSB before doing it. I got alot of help and advice from John and a few others that had alot more experience than I did at the time. I will be more than happy to give you my reasons for it and experience and any info I have for the notes. Let me know and we can get together some time.

[chrismhaase]

Thanks for continuing to work on this topic. I really wish I could have made it to the meeting, especially with starting a new system. Bryan, when you do publish it, is it going to be on here or as a word document on tampabayreef.com?

[WarDaddy]

It will be on TampaBayReef.com in the Education Section. You will be able to download it as a PDF.