Who likes a nice bare bottom? ;)

[biotoxin]

Ive been pouring over some forums lately and it seems a lot of people are reverting back to a bare bottom and 1" sandbed. So im gona post this question on a few forums. If you could do it again would you go with a dsb? And, will you do a bare bottom tank in the future? If so , why?

[loganj]

Yes, I would do the DSB. I don't think I'd want to do a bare bottom tank. I might try a 1" sandbed with a DSB in a large sump and/or refugium though. I think the DSB not only adds biodiversity to the tank, but is invaluable in controlling nitrate. JMHO.

[biotoxin]

my friend said his coralline really started to grow after he went to a bare bottom. is it possible that the dsb not only soaks up detritus but additives as well?

[loganj]

I wouldn't think so. I guess some things might get trapped in there, but I don't think it's enough to matter. The DSB, if composed of aragonite sand, will slowly dissolve and help keep alk up. My coraline is a nusiance...contiuously scraping it off the front glass...and I have DSB's in all my tanks.

[Biggen]

I would definitely go DSB. I think it is amazing that in the few short months that my DSB has been running, my nitrates have stayed undetectable. Really a cool thing to see.

Besides, bare bottoms are for science experiments and laboratories. Just looks so unnatural, at least to me.

[fishfreek]

DSB, DSB, DSB

I have setup three tanks this way and when I set up some more its going to be more of the same. A bare bottom is just empty and cold looking. Barebottoms where the norm a long time ago when us hobbists knew less about the natural nitrafication properties of a deep substrate.

Bare bottom is cool if you have somewhere else to put a DSB out of sight...

I believe that it is essential now days to have a DSB unless you want to do a lot of water changes to keep down those Nitrates. I believe skimming alone cannot combat it.....

[e-cat]

i think a plane glass bottom is ugly too look at, i dont have a DSB nore do i have a nitrate reading over 5 at any time usually at 2 and under

Originally Posted by e-cat

i think a plane glass bottom is ugly too look at, i dont have a DSB nore do i have a nitrate reading over 5 at any time usually at 2 and under

Nor do I. 1-1½" at best!


Cheers
Steve

[e-cat]

Originally Posted by steve-s

Nor do I. 1-1½" at best!


Cheers
Steve

mine is also at 1 -1.5"

[wseaton]

The reason that bare bottom tanks work is for a couple of reasons.

First, while a DSB is a natural Nitrate reducer, LR will eventually take over the job for nitrate reduction over a period of time. Those tanks I'm seeing with zero nitrate and bare bottoms tend to have massive amounts of healthy LR and/or be very established. Just like ammo/nitrite reduction, the bacteria that take care of nitrates soon will migrate to the most efficient location, which is logically where nitrites are being consumed, and that should be inside your LR. It's usually the guy with the 4month old tank, 150lbs of showcase Fiji LR, and a couple inches of CC that is doing the most complaining about high nitrates.

While I use DSB's on my tanks and also have nitrate levels that can barely be detected, I'd yank them in a heartbeat if I knew my LR was ready to take over. An inch of substrate is fine with me, looks good (better than bare glass), and isn't deep enough to be a toxin sump.

[possum]

Please explain why the bacteria will move to the liverock. I was under the impression that nitrate reducing bacteria live in places which have NO oxygen. While i was also under the impression that your liverock is supposed to have water flow over it at all times which will keep anaerobic pockets from forming there which would tell me that anaerobic bacteria can NOT live in the live rock. Correct me if I am wrong but this is just the understanding i had.

Originally Posted by possum

Please explain why the bacteria will move to the liverock. I was under the impression that nitrate reducing bacteria live in places which have NO oxygen.

LR is an anoxic nitrate reducer meaning low O2. The bacteria that live in a DSB are both anaerobic and anoxic. The difference is in how the bacteria convert the nitrate. Anoxic bacteria, expell CO2 and nitrogen for the most part while anaerobic bacteria expell methane, hydrogen sulphide as well as the afore mentioned two.

While i was also under the impression that your liverock is supposed to have water flow over it at all times which will keep anaerobic pockets from forming there which would tell me that anaerobic bacteria can NOT live in the live rock. Correct me if I am wrong but this is just the understanding i had.

Due to the porous nature of most rock, it is not that likely you will get anaerobic bacterial develpoement but rather anoxic which in turn will do the same thing as a DSB given enough quantity and time...

Cheers
Steve

[alrmc4]

im with steve-s and e-cat but i went with the 1-2 inch of sand not just for looks but was concerned that a toppling rock could take out the bottom of the tank with no cushion.

[wseaton]

Bacterial nitrate reduction takes place in areas of low O2 content, not fully anerobic. More of a transition layer from one to the other. There are some really good sites on this topic, just off hand I can't remember them.

Just how deep your sand bed has to go to get the optimum for one and not the other seems to be a point of contention.

Good LR has generous porous regions that are deep and semi-anerobic regardless of water circulation over the surface of the rock. They get waterflow, but very little, and hence they help with nitrate reduction. It just takes longer to establish. This is why anti-DSB reef-keepers are able to vacuum out their sand beds of a 3 year old tank and have no adverse affects. The LR has already established enough diversity to take over the duties.

[possum]

Originally Posted by steve-s

Due to the porous nature of most rock, it is not that likely you will get anaerobic bacterial develpoement but rather anoxic which in turn will do the same thing as a DSB given enough quantity and time...

Cheers
Steve

ok now please explain the difference in anoxic and anaerobic....near as i can tell from looking around they are the same thing.......

An anoxic area is one that has very low O2 and an anaerobic area is one that is void of O2. The both do basically the same thing but each in a different way, the desired end result being nitrogen gas.

Cheers
Steve

[MR294]

I got rid of my DSB, and I haven't been happier with my tank

[Biggen]

I got rid of my DSB, and I haven't been happier with my tank

Really? I love mine. But I like the looks too, so I guess guess it fits me perfect.

IMO, from the reading I have done, the reason most DSB's fail is because they either weren't setup right from the beginning (i.e. wrong grain size of sand, sand not deep enough, or didn't seed the bed) or the DSB weren't given enough time to establish themselves and people got disgusted with them.