Why do ugly black lines appear in a DSB

[Reefscap]

 

[Reefscap]

What is it,looks like sewage to me.

 

[Anonymous]

Black areas in DSB's is the production of Hydrogen sulfide/sulfate. When denitrifying bacteria don't have enough nitrate to reduce they utilize the next thing available: sulfate.

 

[Yellowboy]

so are these lines a good thing because it means you have little or no nitrate or a bad thing because of the products or what?

 

[MattM]

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Yellowboy:
<strong>so are these lines a good thing because it means you have little or no nitrate or a bad thing because of the products or what?</strong><hr></blockquote>

If you read Rob Toonen's papers on deep sand beds, the nitrate reduction zone overlaps the sulfate reduction zone. So by that logic, you're not getting complete nitrate reduction unless you also get hydrogen sulfide.

So in the first case it's a good thing.

Ron Shimek has published data that indicates the stories about hydrogen sulfide emmisions killing everything in the tank were purely supposition and dogma - it simply doesn't happen. Yes, hydrogen sulfide is deadly poisonous, but the incredibly miniscule amounts produced in an aquarium have no effect at all.

So in the second case it's not a bad thing.

 

[Reefscap]

Sounds reasonable

 

[Yellowboy]

good cause mine has black lines too

 

[Yellowboy]

wait i got another question. how would you suggest moving a tank with a dsb so as not to horribly disturb these layers and thus lessen the capabilities of the dsb to reduce nitrate? I dont wanna have to re-cycle

 

[Yellowboy]

i love how i now quasi own this string when i was the third to post on it if that makes sense cause i made it mine, soon i will rule the world!

 

[fish esq.]

Yellow: with only 2-3", I technically don't have a DSB, but my tank was well established when I moved it. Don't worry about it, especially if your tank has been stable for some time. I moved my tank about 1.5 years ago; had the LR out of water probably for close to 4 hours and the SB shifted quite a bit during the move, and it was starting to emit an odor when I put new NSW into the tank. The re-cycle was so quick it was almost uneventful.

 

[Anonymous]

IIRC you can remove layers at a time, BUT IMO I'd just deal with it. Anytime you seriously move a tank you are basically disturbing an ecosystem and that is going to cause some turmoil, however it should reestablish itself after a short period.

BTW just as a clarification, it's not that Hydrogen sulfide is not produced or not toxic but that those sulfides are immediately converted to sulfates should any oxygen be present. H2SO4 is much safer than H2S.