disturbing the DSB

[dsp]

I love my DSB. In my previous system I used crushed coral for years and could never get my nitrates lower than 20. Now with my DSB and a pretty heavy bioload the nitrates never go above 2. The reproduction of all of the micro-organisms has been amazing, I even have hundreds of baby snails and several baby lettuce nudi's now.
My question is reguarding my blue spotted jaw fish. They love digging in the sand and spitting it all over. Personally I feel that the bactreria and other micro-organisms that they release into the water when they do this are beneficial to my acros, but I have heard people say that moving the sand around could be bad. What ill effects could come from moving the sand around?

 

[thomas712]

Well understand I'm no expert. So take this as an opinion only.
A DSB is what houses anerobic bacteria in the lower half, where you will find it working to convert Ntrates into Nitorgen. This in theroy is an excellent filter and finished the denitrification cycle. It does not break ammonia or nitrites down, it only works on the nitrates.
What happens if you or a fish were to desturb this is would be like opening a nutrient sink that suddenly overflowed. You release nitrates into the water where so called hydrogen sulfide is built up, which on its own does not normally rise up into the water colum only if it is desturbed. You also release anerobic bacteria to the water colum. This is all bad. To me the sulfide would be the most leathal to the fish and stink to high heaven. Depending on the nitrate spike this too could cause problems with fish and corals, rapid breathing, stress, eratic behavor
It take time and paticents and maturity for your sand bed to develope and function properly, where you stir it or it is damaged then it needs to heal itself like a scar it can take weeks to recoup from this. The whole thing could crash and force you to start over.
Thats the way I see it................Next
Thomas

 

[barracuda]

Very nice explanation Tomas!!!
DSP,
For more info about DSB go to this link (in my web site). Check the bottom of the article.
DSB

 

[dsp]

Thomas, thanks for the reply. I was going to say that I had read some where that toxic levels of hydrogen sulfide were not likely to form in the sand bed and after reading through the article that barracuda gave me I realized that was the one. So is this really a concern or more of a myth? It does say to avoid animals that eat the small critters in the sand bed, which my jaw fish do not. They like to dig under rocks to make caves for themselves. My jaw fish have been with me since I've set up the sandbed a little more than a year ago and only dig in two spots. Using your scar analogy, would it be safe to say that those to parts of the sandbed are permanantly scared and useless, while the rest is functioning normally? I feel as though it is working great because I have the little bubbles and the almost undetectable nitrates, as well as lots of diversity.

 

[dsp]

Have either of you known or heard of anyone having problems with hydrogen sulfide being released into their tank or outrageous nitrate spikes? I'm a tad worried.
How long would it take for hydrogen sulfide to build up in the sand?

 

[thomas712]

As far as I know Dr. Ron that wrote the article that you read is the leading DSB expert. He has done extensive studies that have helped this hobby tremendously, However I have never heard of a DSB (anybody correct me if I am wrong here) last much over 5 years. Even Dr. Ron (if I recall correctly) had a DSB crash on him last year after about 4.5 years, which I heard about on another forum.
Here is a quote from the article that bothers me:
"The final imaginary problem, the presumed need for sifting in a healthy sand bed, simply does not exist. Small organism movements "sift" the sand sufficiently. Any other sifting of a healthy bed will cause serious harm."
The last sentence is a cliff hanger What harm does it do? Been meaning to e mail him and ask. Perhpas the BangGuy has an answer.
I do not have a DSB but rather prefer a SSB = shallow sandbed.
I have read threads in other places where a DSB has crashed. Its a nightmare. But you really do not hear of it that often, or the blame is given to something else.
Once again I am no expert on DSB's and can only give you my opinion based on what I have read, not experienced.
Thomas

 

[barracuda]

In case with sand sifting gobbies there is another modification of DSB can be made. This one called Plenum. Plenum differs from regular DSB as it has protecting acrilic screen between most bottom layer of the sand and the rest of it. I'm still not sure if it's safe to have sand sifting animals with DSB.

 

[dsp]

4.5 years is a little disturbing. I have come across theories reguarding the 'old tank' syndrome and think that I may have experienced it a few years ago, but I had not heard of sandbeds crashing only after a few years. I guess it is hard to say with it being a relatively new trend. I guess that if the deep sand and the jaw fish seem to be working for me right now, than I should just enjoy my tank for a few years before starting over again!
Thanks for your input guys.

 

[mini-reefer]

Ive got basically the same issue. The only BIG difference is that my culprit (Queen coris Wrasse) loves to just dive into the DSB and come up somewhere else. She also eats any living thing she finds while scavaging the sand bed. Shes always flipping over rubble with acro cuttings mounted to them and small rocks and....... damn fish, so much for research.
I should have known better when NM Reef told me about his Wrasse causing the same issues. Although I really dont want to tear down my entire tank to catch one fish. My tank is a year old next month so I'll just wait like DSP and see if any problems arise.
Good luck with yours DSP.