Please visit our Sponsors
FAQs about Marine Substrates: Yes/No, Bare-Bottom?

Related Articles: Marine System Substrates (Gravels, Sands) by Bob Fenner, Marine Substrate Options by Sara Mavinkurve, Deep Sand Beds, Live Sand, Biofiltration, Denitrification, Live Sand, Live RockBiominerals in Seawater, Understanding Calcium & Alkalinity

Related FAQs: Marine Substrates 1, Marine Substrates 2Marine Substrates 3, Marine Substrates 4, Marine Substrates 5, Marine Substrates 7, Marine Substrates 8, Marine Substrates 8, Rationale, Selection, Reef  Substrates, By Type: Aragonite/s, Coral Sands, Silicates, Dolomites/TapAShell, Southdown & Such, Collecting Your Own, & Physical Make-up, Size/Grade, Location, Depth, Marine Substrate Cleaning 1, Marine Substrate Cleaning 2, Moving/Replacing/Adding To, Marine Substrate Moving/Replacing/Adding To 2, Substrate Anomalies/Trouble-Fixing,


Sand Bed Question'¦Functionality -- 11/09/11
Hi WWM crew!
<<Hello Adam>>
It's been ages since I've required your advice, mostly because I've been tankless for a good long while, but the 260 gallon system that's going in to the wall of the house I'm building is nearing completion.
The sump and frame are installed, we're just waiting for the display tank to be built.
My question for you is regarding sand beds. I know you guys advocate deep sand beds,
<<Some do, yes'¦me included>>
but as I'm sure you're aware there are also very vocal schools of thought out there that thinks they are unnecessary/problematic.
I have intentions of keeping wrasse fish species that require a sand bed, so I fully intend to have one, but the specific mechanics of it are yet to be determined.
First - here's my tank dimensions: viewable on two sides,
71.25 inches long
34 inches wide
27 inches tall
<<I do like the added depth, front to back>>
There will be two internal overflow boxes (unfortunately, couldn't be avoided this time) on the long ends, and I plan on having three rock islands, but a relatively open aquascape.
<<Mmm, yes'¦just recently revamped my own 96x30x30 in-wall display using the 'negative space' methodology>>
It will be powered by 4 Vortech MP40s (or possibly 2 MP40s and 2 MP60s if I can afford it) and a 5500gph return pump, so my tank should have plenty of flow.
The sump is something of an unconventional custom design, in that it's 26 inches tall, will hold approximately 100 gallons of water when the return pump is running, and has one very large compartment that can be isolated from the main water circuit for automated water changes. There is no dedicated refugium chamber, but there is a 26 inch long, by 8 inch wide, by 18 inch deep (18 inches of water depth that is) chamber that I had initially planned to use as a frag chamber. So the question becomes what I should do for my sand bed. In my original plan, I was going to put a 2 inch layer of either CaribSea Aragamax select or Fiji pink sand and be done with it. However I've been reading more and more about the importance of sand beds, including your primer on DSBs, and I now think 2 inches in this aquarium would be the exact wrong depth.
<<Maybe'¦maybe not. I have seen some very nice systems utilizing sand bed methodologies that seem to go against perceived logic/standards. Things like stocking densities, feedings, substrate grain size, et al aside'¦I think it just has much to do with maintenance'¦or maybe more precisely, 'how much maintenance' a hobbyist wants to take on>>
However, I don't want to go much shallower as that could be bad for my fish,
<<Yes'¦ 2-inches would be the minimum for any burrowing wrasses'¦with many authors advocating twice this amount>>
but the other direction starts to send me towards a deep sand bed. In my last aquarium (a standard 90), I had 2 inches of sand and after 1 year I had algae problems that simply could not be controlled. I'm starting to think it's because I had a non-functional nutrient sink of a sand-bed.
<<A possibility'¦but what were the contributing factors to make it so>>
So I guess my questions are this:
1. Would you consider 4 inches of one of the above mentioned sands (0.5-1.5 mm grain sizes) on a tank my size to be a 'deep sand bed'?
<<Re functionality, bacterial stratification? Yes'¦ Would a deeper bed perform better? Maybe so'¦ But we need also to balance aesthetics here'¦what do you want to see when you view the display?>>
2. If I were to forgo a deep sand bed and stick to 1 inch of sand or less in the display,
<<Not recommended'¦if planning to keep burrowing fishes>>
would it be worthwhile adding 6 inches of sand to my frag compartment even though it's relatively small compared to the overall system?
<<It will provide 'some' benefit, even if only to provide a 'refuge' for plankters to prosper'¦is worthwhile in my opinion>>
There will be less flow in that chamber, so I could probably get away with sugar grained sand in there.
<<Is what 'I' would utilize>>
3. What are your thoughts on adding 3 inches of sugar sand to the display tank, then covering it with an inch of courser grained sand like the Fiji pink, or even special grade reef sand (1.0-2.0mm grain size)?
<<You can do this, though it will 'mix' with time>>
Would that still function as an effective DSB?
I'm trying to avoid sandstorms when the Vortechs kick in to full power.
<<Do research/consider setting these up to produce a Gyre-type flow pattern. I utilize sugar-fine aragonite in my display, with Tunze Stream pumps configured to produce a gyre-type flow pattern'¦no problems with 'sandstorms' at all'¦unlike previous configurations set to produce random-chaotic flow. I'm not knocking random-chaotic (is used by/useful to many folks), I just think gyre-type flow patterns are more natural and very effective'¦regardless of your substrate choices>>
4. If I were to go the DSB route in the display, what are your thoughts about burying rock in it?
<<Creating some type of stable base; as in burying rock, is usually recommended/necessary'¦especially if stocking 'diggers'>>
My planned construction sequence will be to build the majority of my rock structure (2/3 of total rock) out of dry Marco rock, place it in the empty aquarium, fill the bottom of the tank with dead sand of whatever grain size and depth I choose, fill the tank with R/O water, add salt, cycle the tank using the shrimp method, then add the remaining 1/3 of my rock as live rock that I'm ordering directly from a wholesale distributor (the logic being that adding uncured live rock to a pre-cycled Marco rock tank will minimize further die-off during the curing process), then as a last step either add the 6 inch layer of already 'live' sand to the frag chamber, or inoculate the sand bed in the DT, or both.
<<Up to you'¦I would likely do 'both'>>
Thanks in advance and my apologies for the gigantic e-mail.
<<No worries>>
This tank is being built right in to the house and sits right in the middle of the most visible, high traffic area of the house,
so I want to make sure I do this right.
<<You're on your way to doing so. Cheers'¦ EricR>>

Bare Bottom or Coarse Shallow Substrate for Coral-Only Nano -- 10/05/11
Hi all.
<<Hey Tim>>
I'm setting up a 28-gallon NanoCube for coral only (plus a few Nerites, Ceriths, and hermits for cleanup duty).
I have never tried coral before, so I am a total beginner at this.
<<If you haven't found it yet, have a look here and among the links at the top of the page (http://www.wetwebmedia.com/reef1.htm).
I've read most of the substrate discussions here,
but the vast majority concern DSB,
which I don't want.
<<I see>>
Also, fine aragonite is not possible, as I know from prior experience that in this small tank my powerhead will shift it into sand dunes.
So I'm left with the choice of bare bottom (possibly carpeted with star polyps, xenia, Zoanthids, which is appealing) or about 1/2 inch of coarse (0.5 mm - 5 mm) aragonite. The aragonite will (I assume) support valuable benthic organisms better than a bare bottom.
<<Yes'¦or at the least, likely a wider 'selection' of organisms>>
It will also provide a bit of buffering, though admittedly not as much as fine grade. So... considering that I am a beginner and want to keep this as simple and foolproof as possible, do you think I would be better off with a bare bottom or the thin layer of coarse aragonite?
<<For aesthetics I prefer a sand/gravel substrate'¦though the bare-bottom does facilitate better monitoring and removal of accumulated detritus. But I think you would be fine 'either way.' The use of a very shallow substrate as you describe will be easy enough to clean periodically as you would a bare bottom'¦and with no fishes in the system (and the subsequent possibility of overstocking), probably a moot point. I suggest you make a decision based on 'your' sense of aesthetics'¦what does 'Tim' want here?>>
<<Happy to share'¦ EricR>>
Re: Bare Bottom or Coarse Shallow Substrate for Coral-Only Nano -- 10/05/11

Eric --
<<Hiya Tim>>
Thanks for your prompt and thoughtful response!
<<Quite welcome>>
The aragonite I've been looking at is black, which will make a great background for well lit corals. So per your suggestion, that's what I'll go with.
<<Excellent'¦ Do keep that black substrate well vacuumed to keep it looking good as it will certainly 'show off' any detritus as well.

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: