BB vs. DSB

okay guys, just did a 50% water change with ro/di water that i filter myself with the kent brand ro/di filter. i tested the fresh salt mix and the nitrates are 0. all day yesterday i used a powerhead with a hose attached to it to blow off the liverock, to get all the deitrus off of them and into my sump. during the water change, i cleaned out the sump, foam pads and everything that could hold deitrus. i did not vaccum the sand, because when cleaning the liverock all of the surface was cleaned too. so i replaced the saltwater with the fresh mix and tested again. the nitrates are still off the charts. the only thing i can think of, is it's got to be my sand. i guess with my velvet damsil blowing the sand around to make a cave like home behind the rocks, the sand isn't deep enough to be anaerobic for the bacteria to live. i'm thinking about vacumming the sand, afterall it would be no different than having a bb tank. right? if the liverock houses the nitrifying bacteria, vacumming the sand shouldn't cause a crash---i hope!! unless the bacteria moves to sand and every water change would reduce their numbers over time. my sand could be too deep for shallow sb and not deep enough for a deep sb. i am soooooo confused!! damsil (1.5 years old)and green brittle star(2 years old) small group of button polyps which is barely hanging on, good color(brown with neon green centers) but not expanding tentacles. thats all i have left after a mass kill about a year ago. back then i had no sump, skilter 400, fluval 307. one day i turned the skilter off because it would always clog up and run over the top of filter pads and fill tank with micro bubbles. knowing the fluval 307 is rated to run tanks up to 75 gallons and mine was only 29, i just left the fluval running. not thinking, the tank didn't get any oxygen because the return line is under the water level. i have to say the velvet damsil is one tough fish, lost it's color, but the only fish to survive.the fish and starfish are doing great now, but i do have a reeftank and want to grow corals. just trying to figure out what to do. any help would be appreciated.

 

Thanks, learned a lot!

 

This is a great thread because by highlighting the amount of controversy over just one component of the aquarium shows just how complex the hobby is. I think the amount of uncertainty in the outcome of ones efforts is a good measure of how rewarding a hobby is. If these issues were resolved and the results were obviuos, it would be a job not a hobby. This discussion is a perfect analogy of why this hobby is cool.8)

Anyway I do have two cents to add. I think that over time many of the important species we assume are doing what they do in nature are absent from the tank. I think things going wrong with DSB after a long period could in some cases be attributed to a line of species (anoxic, anaerobic, etc... one guy mentioned viruses) going extinct in our tanks. Even if there is no crash, I think the differences in two people's DSB/BB (and many other tank features) experiences could be attributed to the differsity or lack thereof of certain microorganisms. We test for chemicals and certain molecules but I have never seen a test for the abundance of say, obligate anaerobes. Cheers

 

DSB organisms extinct?

Don't know if anyone is still interested in this thread... It occured to me after writing the previous post that all our typical parameter tests are not really supposed to directly measure all the conditions, rather just used as indicators. Regardless, I would still be interested if anyone with DSB or former keepers have actually directly tested for the microorgs I mentioned such as anoxic bacteria to quantify the processes we think are working or not working. I would like to know what these tests involve. Thanks

 

Your theory has been thought of by others as well. In fact, a number of years back a reef club believed it so much that they did something about it. They had all of their members bring in a cup of sand from their tanks. Then all of these cups were put together in one large tank. Then several months later, members were allowed to take a cup of sand back out. The theory was that people were going to have a more diverse set of bacterias.

Did it work? I have no idea. There are thousands of studies on how substrates act in the wild. There's obviously a lack of grant money to do similar tests in aquariums.

 

Sounds like a great idea! I recently have been reading that doing the (very) occasional water change with real ocean water, as well as live rock exchange is not uncommon among some aquarists. This type of exchange could take care of the depletion of sand org's. However I'd still be interested in methods of doing counts of various organism populations in the DSB or fuge sand filter, etc. Looks like I have some more reading to do.

By the way, for the record I have a sand bed (argonite and natural mud) in my nano which varies from 3-5 inches deep (no plenum or filter underneath). For sifting I have two nassarious and two olive snails, but there are dozens of small snails and IMO a high population of copepods. My main objective for the DSB is to provide alkalinity buffer, added bacteria support media, and aesthetic. I believe there are some benefits (which I don't pretend to know) to making the tank more naturally realistic with respect to the substrate. I have never had cyano or algae grow directly on the sand at all, and I would say my circulation flow is moderate. However slime resembling brown algae does accumulate on the glass below the water level and has to be wiped over the years.

 

Dsb

This is the best video i could find to help you guys out if your trying to make a DSB it is 2 part video hope it helps!

http://www.youtube.com/watch?v=d0mN3W_CZ9Y

 

This thread is 3 years old. Closed.