A reef buddy of mine re-arranged his rocks and disturbed his dsb and woke up the the next morning and found all his fishes are dead and corals are shriveled up. I think it is all the detrirus from the sand to the water or the bad nitrate are released from the dsb. What do you think?
problem with DSB?
- Thread starter tetra
- Start date
Wow,
That sucks big time.I'm in the process of putting a DSB in my tank, after lots of research and my own experimenting with other or no substrates. I've recently seen some people making LR support stands that the LR is actually suspended above the DSB. I like that idea.
Did your friend have a lot of black areas that he disturbed under the LR? I'll bet that that was a big part of the problem. I've been told that unprocessed waste being disturbed is not all that big of a problem, but I'm not convinced of that. I think your friends situation was not all that different from my own, but I did not have a DSB, I had a shallow one that was obviously not working properly, and I think my system was on the verge of a similar "crash".
Can you supply any more info re your friends system specs? Size, filtration, age, any water tests, ect?
Mitch
That sucks big time.I'm in the process of putting a DSB in my tank, after lots of research and my own experimenting with other or no substrates. I've recently seen some people making LR support stands that the LR is actually suspended above the DSB. I like that idea.
Did your friend have a lot of black areas that he disturbed under the LR? I'll bet that that was a big part of the problem. I've been told that unprocessed waste being disturbed is not all that big of a problem, but I'm not convinced of that. I think your friends situation was not all that different from my own, but I did not have a DSB, I had a shallow one that was obviously not working properly, and I think my system was on the verge of a similar "crash".
Can you supply any more info re your friends system specs? Size, filtration, age, any water tests, ect?
Mitch
Did he do any water tests after he found everything dead? Most likely the disturbing of the DSB caused a spike. Even though the DSB was only 2" deep, it's still going to possess nitrifying capability (although the denitrifying capabilities would be reduced). Disturbing the DSB, if it's extreme, could cause it to quit working as a biofilter. The temporary reduction in nitrifying capability caused a spike. The elevated ammonia and nitrite would be the "poison" that killed the fish.
That would be my guess as to what happened. When messing in the tank, try not to ever disturb more than 1/3 of your substrate at any given time.
That would be my guess as to what happened. When messing in the tank, try not to ever disturb more than 1/3 of your substrate at any given time.
I think there is another unknown factor involved. Possibly, but not limited to, your friend works as an auto mechanic and didn't get his fingernails clean before rearranging the rock. Or maybe someone, kids anywhere, dropped a penny into the tank. At any rate it sounds like a poison reaction. One that shouldn't occur just from rearranging the rocks and disturbing the DSB. If you can call 2 inches deep.
I still recovering from a similar dsb wipe out. Rethink the DSB thing before you do it. Its not the sure thing for reef tanks as eople make it out to be. Lose 2, 3 thousand in corals and you'll rethink the whole DSB. I can't wait to get rid of mine when I move!!!!
Erik
Erik
tetra--if nitrate went through the roof, then it had to come from somewhere. That "somewhere" was another cycle of the tank. You can't get nitrates out of thin air--they had to start with ammonia, which was converted into nitrite and then nitrate. That in my mind confirms that the disturbance of the DSB caused another cycle that caused the fish deaths. O2 was most likely a factor as well.
I would have to disagree your disagree (Hmm..kinda like how that sounds!).
How deep are your DSB in the 20G? Can't be more than 3" as any more than that, you won't have spaces for anything else!
If your DSB is being stirred constantly, O2 enriched water mixed over and over with the sand grains, your DSB is not functioning as "denitrator", instead, it is just a large biological filter, like a fluidized bed filter.
What need to occur for the denitrification to take place is a sandbed with minimum agitation for a few weeks. Where between the grains of the sands, O2 is depleted by the aerobic bacteria, anaerobic zone developes. This is the breeding ground for the anerobic bacteria to utilize the O2 of NO3 and thus break down the NO3.
In your sand, you are lacking the anaerobic zone, thus you would not experience the same problem other are suffering when the anaerobic zone gotten disturbed. It would be obvious you never have the problem with your sand being turning over and over.
How deep are your DSB in the 20G? Can't be more than 3" as any more than that, you won't have spaces for anything else!
If your DSB is being stirred constantly, O2 enriched water mixed over and over with the sand grains, your DSB is not functioning as "denitrator", instead, it is just a large biological filter, like a fluidized bed filter.
What need to occur for the denitrification to take place is a sandbed with minimum agitation for a few weeks. Where between the grains of the sands, O2 is depleted by the aerobic bacteria, anaerobic zone developes. This is the breeding ground for the anerobic bacteria to utilize the O2 of NO3 and thus break down the NO3.
In your sand, you are lacking the anaerobic zone, thus you would not experience the same problem other are suffering when the anaerobic zone gotten disturbed. It would be obvious you never have the problem with your sand being turning over and over.
I disagree with your disgree of my disagree....
my dsb ranges from 1" (due to pumps blowing it out) up to 6", its a 20 tall so space is not an issue(but itis a small tank). There is definately a denitration zone as it has been up for 8 months and I can see the distinction of bacteria colors farther down and also the bubble from the conversion to NO2 . The sandbed is undisturbed for several weeks/months until one of the pumps decides to dislodge.
my dsb ranges from 1" (due to pumps blowing it out) up to 6", its a 20 tall so space is not an issue(but itis a small tank). There is definately a denitration zone as it has been up for 8 months and I can see the distinction of bacteria colors farther down and also the bubble from the conversion to NO2 . The sandbed is undisturbed for several weeks/months until one of the pumps decides to dislodge.
You guys' disagrement is not necessarily a disagreement. The fact that the sand bed is disturbed from time to time is inconsequential as long as it's not completely torn up. Also, whether disturbing the sand bed will create undue problems will depend greatly on your bioload. A reduced nitrifying/denitrifying capacity in a tank with a light bioload can be inconsequential, while the same reduction in the processing capacity of the DSB in a tank with a high bioload can lead to catastrophic results.
I caused a similar problem in my 180 about 2 or 3 years ago. On original setup I got the bright idea that if I would throw about 1/4 cup of shrimp pellets ontop of my 2" CC bed that this would jump start the nitrogen cycle. A week or 2 later I added 2" more on top of the pellets. I had good luck for several months untill I stirred the DSB. I lost several fish in 8 hours. They acted like lack of oxygen but I actually think it was HS2 as I saw many bubbles rising and it smelled like rotten eggs. I have since switched to Jaubert Plenum with DSB on top. I'm not sure but the principal seems the best of both worlds.
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