Bubbles from my DSB

[Chauncey Gardener]

A few weeks ago I moved an established FOWLR into a new 55g tank, and
put down about 5" of Southdown sand.

Before long I noticed bubbles under the surface of the sand, and now
it's giving off bubbles like crazy. This activity has increased as I
have increased my light. Now there are small bubbles all over the
surface of the sand bed.

Does nitrate reduction result in free nitrogen? Is that what these
bubbles are likely to be? Looking through the acrylic under the
sandbed, there doesn't appear to be any organic material down there
that is rotting, so I don't know what else it could be.

Are the nitrate-reducing bacteria light dependent?

Nitrates are currently high, at 50 ppm, but I'm hoping to get them low
enough to start keeping some soft corals. I just added plants to my
refugium and I'm hoping that will help, too.

Thanks...

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[richard reynolds]

Chauncey Gardener > wrote in
message news:180720031346390266%Chancey_Gardener@removethi s.graffiti.net...
> A few weeks ago I moved an established FOWLR into a new 55g tank, and
> put down about 5" of Southdown sand.

how big of a change was this, it can effect bubbles also.

> Before long I noticed bubbles under the surface of the sand, and now
> it's giving off bubbles like crazy. This activity has increased as I
> have increased my light. Now there are small bubbles all over the
> surface of the sand bed.

woohoo

> Does nitrate reduction result in free nitrogen? Is that what these
> bubbles are likely to be? Looking through the acrylic under the
> sandbed, there doesn't appear to be any organic material down there
> that is rotting, so I don't know what else it could be.

while nitrate reduction does result in free nitrogen, and bubbles are normal
for a functional dsb, and your high nitrates increases those however odds
are greater that the air in the bed is just slowly escaping from being
tossed around with the new sand, depending on how much you desturbed your
sand bed, it can take 4~6 weeks for a dsb to build up enough bacteria to
consume noticeable amounts of nitrates, which would be required for the
bubbles to be from them.

> Are the nitrate-reducing bacteria light dependent?

yes, but in reverse, light isnt good for them.

> Nitrates are currently high, at 50 ppm, but I'm hoping to get them low
> enough to start keeping some soft corals. I just added plants to my
> refugium and I'm hoping that will help, too.

could be, better measurement would be how much have they either stayed the
same or decreased, without waterchanges.


> Thanks...

--
richard reynolds

[Kevin M]

"Chauncey Gardener" > wrote in
message news:180720031346390266%Chancey_Gardener@removethi s.graffiti.net...
| A few weeks ago I moved an established FOWLR into a new 55g tank, and
| put down about 5" of Southdown sand.

Excellent move.

| Before long I noticed bubbles under the surface of the sand, and now
| it's giving off bubbles like crazy. This activity has increased as I
| have increased my light. Now there are small bubbles all over the
| surface of the sand bed.
| Does nitrate reduction result in free nitrogen?

It does.

| Is that what these
| bubbles are likely to be? Looking through the acrylic under the
| sandbed, there doesn't appear to be any organic material down there
| that is rotting, so I don't know what else it could be.

In a bed as new as yours, they are not likely to be nitrogen gas. Probably
just oxygen from photosynthesis of algae on the surface of, and just under,
the bed. Especially as you say "activity has increased as I have increased
my lighting". I just went from 175wMH to 250wMH, and I had this same
phenomenon, many tiny bubbles on the surface of my 2 year old SB.

| Are the nitrate-reducing bacteria light dependent?

Not at all.

| Nitrates are currently high, at 50 ppm, but I'm hoping to get them low
| enough to start keeping some soft corals. I just added plants to my
| refugium and I'm hoping that will help, too.

That's pretty high. I don't think even a functioning DSB can bring down
those high levels. You'd be well off to take Marcs advice and do a 50% water
change. That will put you at 25, a much more manageable number. IMO, though,
two 50% changes in two weeks would be much better, putting you at around 12
ppm.

Good luck,
Kev

[Chauncey Gardener]

In article om>,
Kevin M > wrote:

> In a bed as new as yours, they are not likely to be nitrogen gas.

Well, I guess it's been about three months now.

Previously I had been using a fairly coarse grade of crushed coral- and
only about 3" deep. The Southdown of course is much finer, and the bed
is about 5" now.



> Probably
> just oxygen from photosynthesis of algae on the surface of, and just under,
> the bed. Especially as you say "activity has increased as I have increased
> my lighting".

Yes- a very plausible hypothesis- I hadn't thought of that. The only
thing that counts against it (maybe) is that when I moved some rocks
around today, there was quite a bit of gas trapped under the rocks. If
it originated in the sand under the rocks, I wouldn't think any algae
there would get sufficient light. But maybe.

A water change is good advice though... if the bubbles slow down then
this would be a sign that they were connected with the high nitrate
levels.

Thanks all for the feedback!

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