Hi Eric,
I have a few points I would like to discuss with you on this article:
In order for ideas such as those presented in this article to become effective and proven, they must stand up to several principles. First, they must "stand the test of time." Something that seems effective over a short period of time but often seems to show another (often contrary) effect over longer periods. Second, the ideas or practices should be based upon sound methods or upon concepts with some "raison d'etre." Third, other potential trials by others should be carefully analyzed with skepticism rather than with a "bandwagon effect." In other words, being cautiously optimistic produces less observational bias than being gleefully expectative (otherwise known as easily disappointed, rash, or even stupid).
Isn't this the way the DSB methodology was adopted by most hobbyist?
You mention later in the article that you came to the conclusion that a DSB would last at least 7 years because that was the age of your DSB. It seems to me that I read where your reef tank crashed a few years back, was this another DSB tank that you were referring to?
Detritus was a constant problem; the bare bottom accumulated the material and made it visible and unattractive, so weekly siphoning of detritus was part of the maintenance routine. Of course, detritus was minimally removed by skimming because there was really no way to get good water flow in the tank because it was crammed full of rock, and so waste material just fell to the bottom like so many snowflakes on a windless winter night.
I agree that this would be a problem, in fact, one of the very first things a reef hobbyist should plan for IMO is how to remove detritus from their system. Leaving detritus in the system, as we all are aware of, will result in P being the final product.
A few skeptics during this time recommended removing portions of the sand bed due to feared or postulated nutrient accumulations, though there was no evidence to support such a thing actually happened.
Do you feel that a DSB in a closed system will act exactly like a DSB in nature? If so, which sort of an environment would it most closely resemble?
In fact, one of the benefits of using sand beds was that detritus and waste was utilized by the sand bed fauna, flora, and microbial community, enhancing denitrification and allowing the use of less live rock with the corresponding increase in water flow throughout the tank. And this is exactly what sand beds do, in a nutshell.
I agree, what happens to the P though?
It is perhaps ironic that the methods developed for successful reef mesocosms by Adey (1983) had already promoted and utilized deep sand beds
Did you realize that not one of Adeys original public reef aquariums utilize his "natural" method as he first prescribed?
"Jaubert method" (Jaubert 1989) strictly depended on the use of heavy carbonate beds
...which is a plenum system and in no way should be confused with a DSB as defined by you and Ron.
that Julian Sprung wrote about his successful application of Jaubert-based tanks in the early 1990s, and that I established my first pure Jaubert system in 1994
Not one of the DSB threads that I have been involved in here on RC has questioned the validity of the plenum system.
to great success for many years, and continued to run (even today) tanks filtered naturally without the use of skimmers.
Then later you say:
While my current main tank is skimmed, I long for the days when I was home all the time and could again feel safe running the tank without a skimmer as I do on other systems, or when my tank "had never looked better" in the late 90s (although I have to say it looks pretty good tonight).
I am confused here, why are you running your main tank with a skimmer if the "natural" method works so well?
Now, it seems people are pulling the plug on their sand beds and going back to heavy skimming and bare bottoms - a fifteen year old method whose inadequacies were the cause of the bare bottom demise in the first place.
Do you feel that it is possible that the method that was used 15 years ago ( cramming the tank full of L/R and corals, inferior pumps and protien skimmers, etc...) is possible to improve on today?
In its place, we have a host of new (and expensive) mechanical filters, phosphate products to be used in special apparatus,
Interestingly the majority of posts I have read where people are using these products have tanks with DSB's in them. How does a DSB deal with P?
and never do water changes on my main reef tank intentionally
Would you mind expounding on this a bit? What exactly are you doing that would allow you to not do water changes?
Fortunately, there are now real answers to these speculations on sand beds, and I sincerely hope that they are read and understood and practiced as being more valuable than the opinions and observations of people who have had problems and would likely never admit or even know why the other causative factors were involved.
There has been a thread running on RC now for the last 8 months or so that asks for any scientific links that show a DSB will last indefinitely in a closed system? Many of the people who participated in this thread, and others like it, are experienced reefers with some having degrees in the Marine sciences. If you have any links you could supply (last I checked there were none) that supports your case for DSB longevity, please post to that thread.
Sorry to take up so much time with all of these questions, but like you, I feel that the hobbyist should be aware of the "science" behind DSB's in order to make an educated decision on their merits.
Steve
