Amount of Crush'd Coral

[Chucky]

My 10 gal nano has the option of 7.5 lbs crushed coral, or 14 lbs. aside from 10lbs live rock (cured).

It's currently got the 7.5 lbs in it...any suggestions as to the best way to go??

 

[Fatal Morgana]

It really depends on how deep you want the sand bed to be. More sand, less room for the rock and fish.

 

[Ben1]

FWIW, CC IME is a bad substrate. It's too course and collects lots of detritus. In a 10 I would go BB, but if you want sand try finer, atleast sp. sea floor grade sand.

 

[Fatal Morgana]

I used crushed coral, and I agree with Ben's comment.

 

[Reefguide]

In a 10g water quality can take a turn for the worst very quickly. CC is a very bad idea. Idealy you would want a DSB but thats not realistic, you wouldnt have room for much of anything else.

 

[Unarce]

Hey Chucky,

I usually just post this template for certain sand bed questions:

If you were to set up a reef tank with high current, than there would be a lot of bare areas if you had a SB less than an inch high. 2-3 inches is the absolute best way to go. It would be incorrect to claim that a sand bed provides 'more capacity to nitrify and denitrify' simply because it's deeper.

"As much as 70 to 90 percent of the overall denitrification was located in the uppermost centimeter. The remainder was found at 1-3 cm depth"

-T.K. Anderson 1984 "Diurnal Variations of Nitrogen Cycling in Coastal, Marine Sediments."

"anaerobic habitat can be as small as 1mm, that aerobic and anaerobic bacteria essentially coexist, and that as little as 0.08mm distance is sufficient for nitrification and denitrification to take place simultaneously."

-Ecology and Evolution in Anoxic Worlds. Oxford University Press, Fenchel, T. and B.J. Finlay. 1995.

The misunderstanding is that areas with low levels of oxygen are a must for denitrification. Since we now know that aerobic and anaerobic bacteria exist together in the upper portion of the SB, than the heavy oxygen levels of our tanks would not be a factor. It's unlikely that denitrification will occur in the deep areas of a DSB, especially if nitrates never reach it in the first place.

I'd also like to point out that a deeper sand bed doesn't necesarily equate to more biodiversity of life. A shallow sand bed of numerous grain-size will create a number of different environments housing more life than a DSB.

 

[Unarce]

Here's another regarding grain-size:

Another misconception is that the smaller the grain-size, the more surface area there is for bacteria. This would certainly hold true if we assumed that every grain was a perfectly round sphere. But, take into account the rough edges, crevices, and porosity of larger grains, then it becomes quite comparable.

Like many, I like the pleasing aesthetics of fine sand (which makes up most of my shallow sand bed). But, having multi-grains with the larger pieces turning into miniature live rock themselves has certainly added to the sand bed's functionality as well as its appearance.

I certainly agree that exclusive use of CC is a detritus trap. You could perhaps mix some of it with small and medium grain sizes for a sand bed.

 

[Reefguide]

reefnutz,

Well, the nitrogen bubbles I see in my DSB aresn't in the upper 1-3cm.... Why is that? If what your sayiong is correct shouldnt the bubbles only be in the top layer??

 

[Unarce]

You would want to avoid a build up of bubbles in a DSB, build up isn't as much of an issue with shallow sand beds. Proper maintenance of a DSB requires occasional stirring.

DSB's are very good at processing inorganic nutrients. That could be the reason why the bubbles in a DSB are assumed to be NO2 (nitrogen), which is bad if it were only that. A healthy cycle would have a balance of creating nitrogen (N2) and carbon dioxide (CO2) gases, a specialty of shallow sand beds which are also efficient at processing organic nutrients.

If nitrogen reaches high levels in a DSB, the algal blooms or cyanobacteria that so many suffer or have suffered through will eventually occur.

 

[Reefguide]

Proper maintenance of a DSB requires occasional stirring.

I've always been told that stiring a DSB was bad. That you would destroy the different arobic and anarobic layers of the DSB and possibly the critters. I've also been told that burroing fish were a bad idea for the same reasons.

 

[Unarce]

I don't know what the recent trends are, as many are successful with shallow sand beds, DSB, and BB. In my years of reefkeeping, I've simply avoided DSB's mostly because they're unattractive (but can be hidden in a deep setting stand). From what I've seen (and read from some of the board members here), those that have successfully maintained DSB's for 5+ years, utilize some maintenance or stirring methods (i.e. hand-stirring, hurricane treatment, etc.). Even replacing portions of the DSB with new sand on an annual or bi-annual basis.

I think the key is realizing that a DSB is not self-sustaining, and should not be considered a set-it-and-forget-it function of your reef.

 

[Chucky]

So my 8lbs of CC is a detritus trap with a few red hermits? How often for feeding froz brine shrimp, froz blood worms, froz daphnia? Once a day?

 

[Reefguide]

Yes CC is nothing but a nutrient trap. Now about the feedings? What are you feeding exactly? How many fish? I have few fish and feed about 2 times per week.

 

[Chucky]

An orchid dotty back, the smallest clown I can find, (what won't grow much) 2 red hermits, a coral or two...possibly well an anemonemone...will be sure everyone can handle the low light level - 14W powerglo

 

[Ben1]

Anemones wont work under a 14w light unless it is a BTA right under the bulb fed everyother day atleast. I wouldnt even try it.

Your tank is 10 gal, I would be feeding flake soaked in selcon on and off with a bit of dethawed frozen mysis shrimp once both fish are in it. You could keep a perc or a clakii but I wouldnt consider a maroon or tomato an option.


I would yank the CC and go BB, then maintan nutrients by using WC with RO/DI in small portions when ever detritus builds p on the bottom. I would also have a spray bar or powerhead blowing under and behind the rocks to keep the detritus in the front of the tank so it is easy to syphon out during the small WC's.

JMO