Re: DSB/Wet-Dry/Nitrates - 09/01/06
Hi Eric!
<<Hello Heather!>>
I think I'm becoming your groupie.
<<Hee-hee!  Cool, I think you're my first!>>
Thanks so much for your speedy reply. I was shocked how fast you wrote back.
<<A matter of timing/luck for the most part>>
And it's nice to converse with someone who cares about this hobby and doesn't roll their eyes at me when I ask too many questions.
<<Mmm, indeed...too bad your LFS doesn't see the value in education/keeping their customers in the hobby...or maybe they just don't have the capacity re>>
(Well maybe you are but I can't see it at least like at my LFS)
<<Ha!  I'll never tell! (and spoil my image <grin>)>>
I've been reading and am considering the Tunze Turbelle Stream pump.
<<An excellent choice...I use these for water movement in my own system>>
It's around $190.
<<Not cheap, but excellent quality/engineering/performance>>
Is it all inclusive or do I need to buy anything else with it?
<<Based on the price I'm guessing you're looking at the model 6080?  This is a synchronous-motor pump (does not run on a controller/wavemaker) and is ready to go out of the box.  But, depending on your tank design/bracing, you may need one of the holding device extensions (3000.244 or 3000.260).  These should be available on the site where you purchase the pump (if not, they can be found at MarineDepot.com), just review the information on each and determine which is needed (if any) for your tank>>
The internet stores don't really say much but they talked about timers and wave controllers.  Is any of that necessary?
<<No...and not possible with some pumps/powerheads>>
Where is the best place to put it in the aquarium?
<<Hmm...distal from the sump return line...and positioned toward same for creation of a random turbulent flow pattern>>
Would one be good since it says it pumps about 2250 gph on top of my 1200 gph I'm already getting?
<<If this creates enough water movement to keep detritus in suspension/eliminate dead spots, yes...will likely take a bit of experimentation to determine the optimum position (or number of powerheads required)>>
I have a feeling that more gph would definitely help with the Cyano.
<<Me too, though other factors to consider as well.  Have you read our articles/FAQs on blue-green alga?  Here's a good place to start: http://www.wetwebmedia.com/bluegralgae.htm>>
I always worried 5X wasn't enough flow but again my LFS disagreed with me.
<<You must evaluate the needs/requirements of the livestock, but it is likely an increase in flow will be appreciated...even "enjoyed">>
I'm trying to find another LFS but I live in Melbourne Beach Florida and unless I want to drive 90 minutes there are only 2 close by.  I'm not too happy with either.
<<I see...best to arm yourself with "your own" knowledge/research>>
You were right about the 300 ppm nitrates hurting fish.  When I sat down and worked out where all my fish losses were from, they were all from that store.
<<Indeed...as if the stresses of capture/transport weren't enough already...>>
I think I lost 8 out of 10 of the fish purchased there for a loss of about $500.
<<a pity>>
All my other fish purchased elsewhere have done fine.
<<Hardly a scientific analysis...but does seem rather telling>>
I guess they only care about the bottom line.
<<Unfortunately there are stores out there with kind of short-sightedness>>
Neither store carries live rock and the store that did and had a conscientious owner (shocking), went out of business.
<<...why does it always have to be the good one's...?>>
Do you recommend any internet sites for quality cured rock?
<<Some of the members of my local reef club have been raving lately about the rock offered at Reefermadness.us >>
I guess that is it for now.  I'd like to purchase a quality pump that gives good gph and add some more LR and see how that goes.
<<Sounds fine>>
I read the links you sent me as well as Anthony's report on pumps and like the Tunze like you suggested.
<<You won't be disappointed>>
Thanks so much! Heather
<<Cheers my friend, Eric Russell>>

Deep sand bed
I have read much on the subject of Deep Sand Beds but nothing that puts it all in a nut shell. Is there anywhere I can look that shows the exact  complete construction of one of these? I have read miles of varying opinions on this subject, so something solid would be quite refreshing.  Actually with as many times you have been asked about this, I am surprised that you have not pointed these people to a complete answer  somewhere. <Take a look here  http://www.wetwebmedia.com/deepsandbeds.htm, Great article by Anthony Calfo.>
3" 4" 5" (with 5" looking like the target) 6" 7" more? Water in plenum starts to heat up causing slow circulation? What is  the normal circulation equal to? (No need for a pump?) <I'm a little confused about what you are asking here, can you please clarify?>
What if I wanted to assist this circulation by sucking out some of the  water under the plenum with a pump, maybe create a drip or something? My sump is a 55gal glass tank that sits on a cold tile floor on its plastic  framing.  Will the lower floor temps affect the warming under the plenum creating no circulation? What should the difference in temperature be between the under plenum and  room ambient or ambient temperature of the free moving water in the sump?  Should I add a heater under the plenum to assist circulation? Would it be to my advantage to create a deeper plenum? (a larger void under  the sand. a larger under sand water pocket) <I don't think a heater under the plenum would be helpful.>
I am trying to get a good comprehensive understanding of what's going on so that I can assure the effectiveness of the process.  <Definitely take a look at the articles on setups. I think you'll find them very useful>
Many Many thanks for all your help.  This is the first time I have ever asked a question here. <You've done well! good luck, MacL>
Sincerest regard,
Paul

DSB & BBT - 05/06/05
Hi Helpful Guru(s),
<Greetings>
With your help, I have claimed some success with my fish keeping for the past year & you people are the "gold" in our hobby. Thanks!!
<Thanks for the kind words.>
There has been a debate among my reefer friends on DSB (deep sand bed) vs. BBT (bare bottom tank). The DSB has been blamed as nutrient sink & BBT is the new & better way of doing it, if you are into SPS. With better skimmer technology, there are claims that one should do away with the DSB & just do BBT.
<If the DSB is working for you, why would you do this? Doesn't it make more sense to enjoy/reap the benefits of both?>
With BBT, you can blow the power heads any way you like & not be afraid of creating a sand storm etc...
<Won't argue that...>
What is your view on this issue?
<I like/prefer the DSB myself. Both can/do work, But it comes down to proper husbandry and proper application of the chosen methodology. I'll grant you that a DSB may become problematic, but ANY methodology will end in disappointment if you don't bother to research and apply it properly.>
I understand that DSB helps mainly in Nitrate Reduction. Right?
<A primary consideration, yes, but other benefits to be had as well.>
Even with a powerful skimmer only without DSB, can one get zero nitrate?
<One can get zero nitrate without a skimmer OR a DSB. It becomes a matter of adjusting stocking levels, feeding, water changes, manual detritus removal, etc.>
Or, the reason that BBT works in SPS tank since minimum feeding is required & hence minimum NO3 generated?
<Faulty logic/information my friend. Feeding and water flow rate above lighting in my opinion (and others here) for success with SPS and indeed all type reef tanks. The idea is to find and correctly apply a methodology where you DON'T have to starve your tank.>
I have a DSB tank housing SPS. Thinking of upgrading to bigger tank. How do I move the existing sand in DSB to the new tank so that all my bio filtration is intact & I need not go through the cycle of new tank?
<So, you want your cake and eat it too eh? <G>.  You must understand, the sand bed is made up of layers of micro- and macro-organisms. The organisms develop and function, indeed survive at differing depths within the sand bed. It's not reasonable in my opinion to expect to move a sand bed without experiencing some mortality of these organisms.>
If I move the sand just like that, I am disturbing it & may experience nutrient leach & toxic tank, right?
<You may, yes, maybe.... But your biggest hazard is a brief infusion of nutrients to feed nuisance algae, the so called "toxic tank" is more myth than reality. In my experience, any "toxic gas pockets" that are released exit the water column very rapidly, facilitated by good/proper water flow, with virtually no effect on the tank inhabitants.>
Does it look like my only viable way is to cycle a new tank with new DSB until it is completely cycled (i.e. 2-3 months minimum); then I can move my live rocks & my SPS over to the new tank?
<Not at all. You will have mortalities within the sand bed as stated previously, but not everything will die, thus providing a "kick start" to the cycle process. You will need to monitor water parameters to be sure, but I believe it's reasonable to expect the relocated sand bed to cycle within a couple weeks or less. You might even reduce that time by using a portion of the sand to infuse life in to a new sand bed if you like. Consider the fact that you will be also adding cured/mature live rock to the system.>
Gee, now you can understand why I am tempted to go bare bottom tank, no such problem in future; just move live rocks & live stocks. May I have your honest view on this matter. I would appreciate it.
<Have tried to do so. Relocating a sand bed is an arduous task. I would recommend seeding a new sand bed with a sizeable portion of the old bed, move your rock and livestock, along with most of the "old" water to the new tank, and go back to enjoying the hobby my friend.>
Thanks in advance.
<Regards, Eric R.>

DSB vs. Plenum (1/14/2004)
Steve (or whichever highly-appreciated crew member is answering today), <me again>
Thank you for the response.  To follow-up on a few of your questions/comments...   
<Why put a plenum in your refugium? A simple DSB should work fine.>:  I have read many postings on this trying to determine the best approach.  GARF.org swears by the use of plenums on all of their "bulletproof" systems. <IMO, no system is fully "bulletproof" either literally or figuratively. Some are surely less likely to fail than others, though. The real key is good maintenance habits.> Even in one of the WetWebMedia postings where someone asked the question "Should I use a DSB or a plenum in my sump/refugium?", the answer was "Why not have the benefits of both?  You can include a DSB over a plenum..." <True> I have read having a plenum can be disastrous but it seems that this happens when a plenum is poorly designed/maintained. <Agreed. Anything can be disastrous if mismanaged.> Of course I want to use what is the best NNR method but I have not found agreement on this. <And you will not find it. Put 3 aquarists in a room and you'll get at least 2 differing opinions.> Do you foresee problems with using a plenum or advantages of a DSB rather than a DSB over a plenum? <I think you can do fine with any of these. The key is for you to be willing/able to keep up proper maintenance. You should consider getting Bob & Anthony's "Reef Invertebrates" book and reading the DSB/Refugium/Algae chapters. Very helpful. The rest of the book is great too. You may also want to read some of Bob Goeman's writings on the subject.>
<Can you make the refugium any bigger?>:  I might be able to make the refugium slightly bigger but it needs to it inside my stand and I would like to maintain *some* room inside the stand to store food, chemicals, etc.  I also already have a spare 20 gal high aquarium, so this is just a convenient fit.  Are you concerned that a 20 gal refugium will have little beneficial effect on a 180 gal aquarium? <Bigger is always better, but 20G is sure to be valuable. Convenient fit is very important.>
Regarding the 100-150 gph flow rate, I should have mentioned that this is the pump's rating.  The refugium will be located about 1 - 1 ½ feet above my sump so the actual flow rate will be reduced.  I do want the flow to be low enough to give the refugium time to react with the water so, I will be restricting this flow if it appears to be too high.  I had read that a flow rate of 3-10 times the refugium volume is recommended.  Do you agree with this? <Yes, but not so much as to disturb the sand bed. I like to be on the lower end myself. 10X flow in a 20G will likely be too turbulent for the sand and the 'pods>

Sump/refugium/deep sand bed - confusion
I have been reading many of your FAQs and doing a lot of internet research over the past couple of months.
<Research is the best thing anyone can do for a reef tank.  Kudos for taking the time to look it all over.>
We set up our FOWLR tank 15 months ago and are now wanting to upgrade to a reef tank.  
Current setup:
77 gal AGA
Fluval 404 canister filter
Seaclone skimmer
4x96W fluorescent light
2 powerheads
approx. 30 lbs live rock
2" live sand/crushed coral bed
<Well, the Seaclone skimmers aren't the best on the market, but it does get the job done.  If you are going to do light loving corals and things like clams you will need some lights that are much more powerful than that.  Check out of the Lighting section on Wetwebmedia.com to learn more about what sort of lighting you will need for the corals you wish to keep.  I myself like a bit more live rock in my tank, one to two pounds per gallon.  But that is all up to personal taste.  If you feel that 30lbs is enough then that sounds fine.  As for the sand bed, With larger tanks many reefers are finding Deep Sand Beds to be very beneficial to the overall well being of their tank.  I myself use sand beds, and skip the crushed coral.  My findings were that large crushed coral has lots of dead spaces for food and waste to rot in.  The sugar grain sized sand in my tank not only looks nice it also offers a low oxygen area for the beneficial bacteria to break down the ammonia.>
What I would like to do is get rid of the filter and plumb in a sump so that skimmer and heater etc. can be hidden.  
<Very good plan, tank looks so much more natural without all the extra stuff hanging in the tank.>
I understand from your site that the Seaclone skimmer isn't very effective and plan to buy a new one (am thinking about the Aqua C EV180).
<A nice skimmer, a friend purchased one recently and he hasn't had any complaints.>
First question - is the 4x96 light strip going to be ok to keep low to med light corals (tank is 20" deep)?  
<Depending on the bulbs you use, and how often you replace them then there are a some low light corals and mushrooms that would do quite well in lighting like that.  Other corals you might need to feed more often to balance of the amount of light.>
I also plan to add 40-50 lbs additional live rock and create a 4" DSB in the main tank. My purposes for this would be NNR and phosphate reduction.
<This is why it pays for me to read the emails prior to answering them.  I had addressed the issues above.  More rock is good, and DSB are great!>
    I am currently battling a hair algae problem which I am fairly certain is due to high PO4 due to a lazy maintenance schedule (nitrite is 0 and nitrate less than 10).
<Getting a bit lazy with tanks will lead to some outbreaks of some weird stuff.  Luckily it was hair algae, which can be eaten by many clean up critters (Turbo snails being a big one).
I did a 40% water change 2 weeks ago, and another 25% change last week and plan to continue on a 5-10% weekly water change using RO/DI water.
<Good plan.>
  My test kit only does PH/Ammonia/Nitrite/Nitrate but plan to buy a better kit.
<having a better kit will definitely assure that you will know much more about your tanks well being.  For corals you will want to know the Calcium and Alkalinity levels.>
I am confused as to how to accomplish NNR - so much conflicting advice.
<Simply put, by having a deep enough sand bed, which should be around 5 inches, you will have a low oxygen area and should offer a great area for the bacteria to grow and do their work.  There are a few good articles in our articles section here on WetWebMedia.  And I also suggest checking out the Forums here as well.  You will meet a few folks that really know there stuff about NNR.>
Does what I am planning sound workable?  
<To me it sounds quite workable.  I've known people have impressive reef tanks with much less.>
I don't have much space under the tank and want components hidden as tank is in living room, so would have to pick either a sump or a refugium.  I am leaning towards a sump as the refugium would never be seen under there and I would have to find yet another outlet to plug a light into.  Basically I need a simple but effective filtration method.  I plan to keep my current tank inhabitants (lawnmower blenny, firefish goby, blue damsel, 2 BBT anemones, blue band goby, and canary wrasse) and add some corals like torch coral, mushroom, xenia, easier LPS.
<Bubble Tip Anemones are more delicate than any of the other corals you will be adding to this tank.  I would do some research into what they need in order to thrive.  Anemones really don't have a great track record in people's tanks.  In fact somewhere between 80-90% of Anemones imported in die in home aquariums due to poor tank conditions.>
Do I need a refugium in addition to a DSB for effective filtration?
<Adding a refugium will be beneficial to the tank in general.  It's not a needed thing in the grand scheme of things with use with DSBs.  But, a refugium will over a larger volume of water, since the depth of the sand bed will remove the effective water volume from the tank.>
Thanks for any advice you can offer.
Barbara Ottley
<Hope that helps.  Good luck, and keep up the research.  I suggest you also look at getting the book "The conscientious Marine Aquarist" by Robert Fenner.  It's a great book and will give you a great deal of knowledge of the subject. -Magnus>

Deep Sand Bed Controversy? 
Hello! 
<Hey there! Scott F. here today!> 
Have to say that I have learned a lot reading all the questions and answers that your group puts out. Thanks!!! I have a 125 AGA tank that I drilled for over flows and for closed loop system, plumbing is ready and now I need to take the next step. 
<Cool! Now the fun starts!> 
I have received, through many of different outlets very good advice, and I want to get your input too. I have a 125 AGA (that will be a reef set up) with a 55 AGA sump. I don't want a BB so depth of sand in each? 
<I'd say 4"-6", if you are shooting for a "true" deep sand bed (DSB)> 
I Have been told 2.5", have been told 4"+, have been told DSB are accident waiting to happen, been told DSB don't work only when people don't put the right kind of critters in it, etc.... 
<Imagine that! Contradictory information on the marine aquarium hobby? Nah! Seriously, there is tremendous controversy and confusion on the application of sand beds in aquaria. It seems to me that the people who claim "disasters" after having utilized a DSB in their systems almost always have other issues, such as questionable husbandry habits, excessive bioloads, unusual animal combinations, etc. "Anomalous" crashes of DSB-based systems usually have their origins in some other problem, IMO. The science behind sand beds in aquaria has been well-documented by the likes of authors/aquarists such as Ron Shimek, Bob Goeman's, Larry Jackson, and our own Anthony Calfo. Yes, there is still controversy and disagreement, even among these people! If you don't believe me, just attend a MACNA conference and listen to the heated discussions on this topic! If properly configured, and if the overall system husbandry is up to par, deep sand beds perform remarkably at processing organics and removing nitrate, as well as providing an area for increased biodiversity in the system. A great treatment on deep sand beds can be found in Bob and Anthony's "Reef Invertebrates" book, and on plenum advocate Bob Goeman's website, saltcorner.com. In the end, having a sandbed is a good thing...If you properly follow the "rules" for the methodology that you like. Choose your methodology, care for your tank diligently, and stick with it.> 
Over flow from tank into sump first passing through filter floss and then over bio balls before entering into sump? I have been told this is to keep the tank from crashing if I have a problem with LR in future, that if I use bio balls I am creating factory for Nitrites, that if I use bio balls they steal the "food" for the LR, if I use floss I steal food for the filter feeds, etc....Please can I have you thoughts on this. 
<If it were me, I'd omit the bioballs, as they do tend to assimilate ammonia and nitrite so rapidly that they cannot cope with the nitrate that is produced as an "end product" of the nitrification process. If you are shooting for a reef system, or one with low nitrates, bioball-"filtered" systems tend to work against you. If you are using other mechanical media, do be sure to clean and/or replace them frequently, so that they don't become nutrient "traps", working against the other good husbandry habits that you are so diligently developing> 
Thanks Jim Mc 
<My pleasure, Jim! Choose your methodology-one that you are comfortable with- and follow the established parameters exactly, and I'm sure that you'll be fine! Regards, Scott F>

Super nutritious DSB/sandbed 5/28/04
Hi WWM friends. Before I undertake emptying my tank and scooping out the sandbed, I wanted to get your advice.
<ironic timing... I just pulled 600 lbs from a tank last night that I wanted to move 15 feet into a new fish room. The sand (supplemented over the years) is nine years old and magnificently full of life. It's unfortunate to me that so many people criticizing DSBs haven't actually ever set them up properly (adequate depth, adequate water flow, etc.)>
I have a 75-gallon reef tank that is home to four ocellaris clowns, five green Chromis, hippo and Atlantic blue tangs, a mandarin, a goby, a royal Gramma, two cleaner shrimp, a peppermint shrimp and the usual bunch of hermits and snails.
<do consider leaving out the hermits... they take a heavy toll on other more desirable life forms in their sand bed>
For lighting I have a pair of 10,000k VHO's, a pair of standard fluor. actinics and one, 175-watt halide pendant (5500k).
<very nice combo>
I have a very large downdraft skimmer in the sump and I use a couple bags of Chemi-Pure and Kent reef carbon in the sump.
<Okey-dokey>
This is a system that I bought used, minus livestock and live rock, eight months ago from someone who was getting out of the hobby. He had run it very successfully for about a decade. About the only thing living that I bought with the system was the sandbed, which I kept intact because it was full of life. I bought it as a 50-gallon setup and transferred the contents after a few months into my current 75-gallon tank (thus the use of one pendant halide on a 48-inch tank). Four months ago, I was having some trouble with red slime and green hair algae and someone from my area marine aquarium group (Central Illinois Marine Aquarists) told me I should be using R/O water.
<hmmm... perhaps. But for other reasons more likely (consistency of evap and source water for new seawater). Not as a solution to a nuisance algae problem necessarily. Do rely on aggressive skimming and strong water flow in large part for this>
After I bought a used R/O system, the tank became miraculously clean. The undesirable algae was gone. I was amazed.
<this was due, IMO, to the overall attuned attention you paid to the tank at the same time>
Well, about a month ago (after three months algae-free), I noticed some red algae and green hair coming back. This red algae was the fibrous kind that harbors air bubbles and lifts off sand and rock surfaces in strands (not the smoother kind that covers surfaces; I can't keep their names straight).
<perhaps a dinoflagellate (the strands with bubbles)>
I changed the filters on my R/O, but that didn't stop it.
<yes... as per above>
My phosphate level tests fine and I'm certain that overfeeding isn't a problem. So at the most recent aquarium group meeting, someone suggested that my sandbed is probably harboring a ton of nutrient and is the most likely culprit for the green hair and stringy red algae I'm getting now.
<complete bunk... and weak excuse that critics use. At best, it is only true when tanks are run without adequate water flow and nutrient export mechanisms.>
This sounds reasonable, and I attached a photo in which I think you can see the red algae growing beneath the surface of the sandbed (sorry the photo is not great). I'm willing to empty the tank and replace all the sand if this is truly the cause, but is there anything else I can do that's not so extreme (and won't smell up the whole house)?
<this is truly not necessary my friend... increase your water flow (approach 20X turnover for most reef tanks... close to 30-40X for hardcore SPS tanks>
Would something like Bio Chem Zorb or maybe fresh Chemi Pure have any effect?
<not likely... too small>
Maybe PhosBan (though the phosphate tests OK)?
<some merit here... test kits testing for inorganic phosphate only when the majority of phosphate in your tank may be organic>
What's weird is how using R/O cleaned up the tank like magic for a few months and now this comes along.
<again... not the RO, but your increased attention to the tank at the same time: water change, fresh carbon, improved skimming perhaps?>
We also have a 29-gallon FOWLR tank that is nice and clean, so I know the R/O is working.
<yes... overall, its a good idea to use purified water of a reliable consistency>
You folks have always been a tremendous help. Thanks in advance for any suggestions and sorry this message is book-length.
Matt Dietrich
<no worries... and please do write back with an update. No kidding... if you increase water flow in the tank and tune your skimmer (clean frequently, adjust as needed) to get it to collect dark coffee colored skimmate near daily, I assure you this algae will be gone in less than three weeks without any other effort. Have faith my friend. Anthony>

Controversial Topics (Sandbed Depth And Caulerpa Use)
Hello,
<Hi! Scott F. here>
I have read through much of the site but still have some questions.  First I will tell you what I have--the contents of the tank have been together--Ecosystem aside--for about 1.5 years in a 100 gal tank:
My set up is this (for about 6 weeks--I took all the water/sand/rock from the 100gal tank):
60 gal tank
100 lbs. live rock
3-4 inch DSB (fine-medium grain size sand--although more medium than fine)
Ecosystem 40 refugium with miracle mud and healthy Chaetomorpha, red tang heaven, and Ulva and lots of pods/snails
AquaC Remora HOT
280 watt PC lighting (soon to add another 110 watts)
Pacific Tang, Maroon Clownfish in love with his Condylactis anemone, Firefish, Royal Gramma, Rock Blenny, Purple Lobster, two hermits and soon to be removed (although cute) Spotted Puffer as well as one sea anemone.  I would like to make my tank non-predator and ready to eventually contain some corals (ergo adieu to the sweet puffer).
<And the anemones, too!>
I inherited the contents of the tank from a friend and bought the skimmer, and refugium (although the Ecosystem 40 is for a 40 gal I figured it is better to have a small one than none at all at this point--and space is a constraint esp. with a somewhat reluctant spouse who 'doesn't care much for fish' I'm trying to keep it all as inconspicuous as possible).  Everyone seems very happy and all the fish responded very well to the addition of the refugium last week (swimming all around the water return...and the normally shy gamma came out and is now all over the tank). No water problems so far.
Questions:
1. I currently have the 3-4 inches of sand with the rock resting on top in the tank.  The sand is different levels due to the two water pumps I put in--they've blown it around a little (I actually think this looks better than flat sand all the way across).  
<Me, too!>
The manual to the Ecosystem refugium says that I shouldn't have a deep sand bed.  My LFS says that that I should have put the rocks on the bottom of the tank, and then filled the tank with sand (three inches) and eventually the sand would settle into the rock.  Should I remove some sand?  Should I try to put the rocks on the bare tank bottom and add sand like my LFS says?
<6 of one, half-dozen of another...I'd keep the sandbed 3-4 inches, and be done with it...>
Will the DSB in my tank disrupt the refugium system?
<I can't imagine what it would>
I would rather have less sand in my main tank but initially put it all in there since I thought a DSB would be fine (I got it all from my friend with a 100 gal)--also...is it a problem that my DSB sand is not all fine grain but more small-medium grain pieces ( read on your site that fine sand is best for DSB)?
<Well, fine grain is best, but it is certainly acceptable (IMO) to have some larger-grade pieces mixed in. Looks better, too! Do read some of the works of Dr. Ronald Shimek on sandbed composition. Lots of opinions on this topic.>
I have noticed that after a month the sand layer is whiter on top to the depth of 1.5 inches.  Should I simply have one-two inches of sand in the tank since that seems to be the amount of sand that is getting good circulation???
<A lot of the conventional wisdom on sand beds dictates a deeper layer. Two inches may be too deep to be fully aerobic, but too shallow to foster complete denitrification. Again, there are a lot of opinions on this, and new data is coming in all the time. However, I'd stick with the tried and true for now: A sandbed should be 3 inches or more, or 1/2" or less!>
If I need to take out sand and re-do the sand/rock would it behoove me to elevate the rock on a PVC/eggcrate setup for better circulation?
<Can't hurt- but it's not 100% necessary. I'd personally try to leave as much surface area open as possible. You could elevate the rock or stack it to accomplish this>
I really want to do what is best for the long-term/benefit of the organisms.
<Agreed! That should be your goal!>
2. Should I add Caulerpa to the refugium?  I have read pros and cons.  I want minimal hassle and am worried the 'sexual life of Caulerpa' will be too burdensome.  But do the benefits outweigh the bother, or will I be fine with what I have?  
<I like and use Chaetomorpha, myself. It grows, it's an excellent "substrate" for planktonic/amphipod growth, doesn't go "sexual", can be easily harvested, and it's fun to give away to your friends (Everyone wants this stuff at the Club "Frag Swap"! Let everyone else offer their "Blue Torts"- Everyone wants my "Chaeto!">
Thanks for your help--it is very overwhelming and time consuming trying to learn all of this and I appreciate all the time your crew dedicates towards helping people like myself (so hopefully in turn I can help others!).
Saskia
<MY pleasure, Saskia! That's what we're all about! Sharing this hobby that we all love so much! Good luck! Regards, Scott F>

Embracing The Right Methodology (Tank Set Up)
Okay, I've read through the link you sent me on the deep sand bed, and understand that it is not voodoo, but indeed a viable option. Now, my friend does a DSB and excellent circulation, with no other filtration whatsoever besides periodically running a skimmer, but not 24/7, in a sump. His tank is healthy, and there is NO plumbing. Under his tank is completely empty. (very appealing) It seems to me that a sump and 24/7 skimmer would be a better way to go,?,?,?,
<I see no reason not to run the skimmer 24/7>
at which point I am plumbing down to a sump, thus defeating the "neatness" factor he has achieved. In YOUR PERSONAL OPINION, would you go with his set-up? Or a DSB combined with the sump-24/7 skimmer? Or simply the sump/skimmer without bothering with the DSB?
<Nope- I'd run the skimmer 24/7, utilize a sump, and also a DSB!>
While I understand that your website is written in a fashion that lets the aquarist make his own decision.......I am asking for your personal opinion. If you were me, which would you do? Thanks so much. Pat
<Well, Pat- I'm glad that you understand that any advice that you get from anyone- is essentially an opinion, and it's generally up to you, the individual, to make the ultimate determination. I like skimmers (I think that they're essential!), love sumps, and really think that DSB's can make for an amazingly successful system. Go for all three, and I think that you'll be quite pleased! A skimmer is your primary line of defense against nutrient accumulation, while a sump provides extra water capacity, a place for chemical filtration media, and (if you light it) area for macro algae cultivation. A DSB, if properly set up and maintained (i.e.; left undisturbed), can provide excellent denitrification and additional biodiversity. These three systems all compliment each other, and provide ample opportunities for fostering biodiversity and nutrient export processes. Good luck with your system! Regards, Scott F.>

Doing It The Right Way! (Planning A New System w/DSB)
G'day Bob, Scott and the rest of the wondrous wet web wizards of the watery depths! This is Rob here from Down Under.
<Hey there, Rob! Glad to hear from you again! Scott F. with you again tonight!>
I e-mailed you guys a few weeks back looking for advice on my plans for my FIRST marine tank setup. Scott was kind enough to reply and let me know that I was basically on the right track. He then suggested I go back and do MORE RESEARCH!!!!!!! And perhaps revise my plans. I have. I also have many new questions, queries and doubts!
<Oh, man- I sent another fellow hobbyist back to the books! Part of the fun, though! >
So, here goes..... I am planning on adopting the following species: 1 DWARF lionfish (max5"), 2 LARGE tomato clowns and 1 bubble tip anemone as a start, I'll take my time with these introducing the lion first, then the clowns and eventually if all goes well the bubble tip.
<Glad you're "easing" into the anemone...No need to rush>
All are available (reasonably) locally and all are caught with nets by people I know well.
<Outstanding!>
Current plans are for a 150 gal (570litre) tank 48"L X 36"W X 20"H nice and wide, good surface area (see I do read your articles!) I will also be using an under tank sump of 56gal (215litres) I am really hooked on the idea of natural filtration so this tank will get about 200lb's (90kgs) of live rock.
<Terrific! It will be a very stable system!>
Skimming will be by a locally made (Aussie, Aussie, Aussie OY, OY, OY) venturi unit running from the sump and powered by a 650 g/h (2500lph) pump. These units are made by a bloke in Western Australia who started building his own DIY setups years ago. They have a brilliant reputation and are much, much cheaper than the units imported from your neck of the woods.
< Awesome- DO support your "local talent" whenever possible! A good skimmer is such an important investment- well worth it!>
Heating will be from 2 - 300W quality units. Lighting will be by fluoro's,  160W of HO and 80W of Actinic (still some doubts as to whether this is sufficient, especially with the anemone in mind.....Your views?).
<May not be enough...Even though your tank is relatively shallow, you might want to add a couple more tubes...You simply cannot have "too much" light for anemones, in most cases...>
All fluoros are very well reflected and powered by remote, electronic ballasts and will be housed in a custom made (by me!) hood.
<The best kind, IMO!>
Circulation will provided mainly from a closed loop running on the inside top of the tank with various injectors placed at strategic locations and depths. This will be powered by the 1050g/h(4000l/h) return pump from the sump. I will have to run some test's to see if this is sufficient, if not extra powerheads will be employed.
<Sounds nice. If you intend to keep SPS or other high-current loving corals at some later time, you may want to consider a pump or pumps that can push 10-20 tank volumes an hour through the system...Like lighting- you can rarely have too much circulation>
O.K. I hear you thinking, this guy's got it together!
<Yep! Very much so!>
Well that's what I thought too! Until I walked into my LFS (600kms away!).
<I've heard of "walkabouts" before- but 600kms...? You're seriously dedicated! I'll never complain about the 20 minute drives to good LFS in my area!>
You see, I had initially intended to use a wet/dry filter in my sump to back up the live rock and skimmer. However on looking closely at the shops fish and invert display tank (120gal) all they had was lots of rock and a protein skimmer! Nothing else! This was a good looking tank with all inhabitants looking bright, cheerful and full of life. I was stunned and intrigued. On talking to the shop crew (Seth and Kath, they make a good team!) they told me that the secret was all in the substrate. Sure enough there it was, 5-6" of good looking fine coral sand with plenty of activity going on.
<A deep sand bed certainly serves as an excellent nitrate reducing "filter"...a nice thing to have>
Anyway I checked it out on the web and found out all about plenum bed construction, Jaubert's method, anoxic bacteria and 0 nitrate levels. After much research I am planning on this stage of using a deep substrate level (5") in my main tank and constructing a plenum system in the sump. The main reason for not using a plenum in both is that I want to aquascape the main tank to resemble a section of reef I know well from diving and having to minimize the rock's 'footprint' would be difficult. I really need your advise on this! Is the full biological filtration method just a pipe dream and is it beyond a beginner like myself?
<No- it isn't! Embracing natural methods is probably the most simple and effective thing you can do as a beginner, or as an advanced hobbyist! Your idea of using a plenum in the sump is certainly workable. I personally prefer "static" ("plenum-less") deep sand beds, as they seem to work as well as plenum-equipped systems (although there is plenty of debate on this topic among hobbyists). If you are going to go the plenum route, it's absolutely vital that you follow the "standardized" recommendations concerning sand bed composition, depth, plenum height, etc. These configurations were arrived at after enormous amounts of testing by researchers like Jaubert, Goemans, Gamble, etc., and are not just random numbers. Most of the people who claim that plenums don't work are the ones who "modify" the parameters of their plenum. You may want to check out Plenum guru Bob Goeman's http://www. saltcorner.com site for a lot of good information on plenums...>
I am aiming eventually to 'get into' corals so the idea of continuing the biological filtration cycle with the break down of NO3 to NO2 to NO and eventually to pure N is highly desirable. I await your advice with baited breath oh wise and all knowing denizens of the deep! Sorry this is so long winded, got carried away, as usual, if I mention the word "fish tank" one more time I might find myself without a house keeper, bed warmer and long suffering friend! Thanks for your help guys and gals!  Rob
<Ahh Rob- I think that you're doing great! It's so cool that you're doing the "modifications" and "tweaking" to your system before the system is actually set up! The time that you take now to research the various concepts will repay you many times over with a successful tank! I think a well constructed sand bed (with or without plenum), protein skimmer, and sump, fortified with aggressive maintenance procedures (water changes, etc.) will greatly enhance your chances of success. Keep in touch, and best of luck to you! Regards, Scott F.>  

DSB vs. Aesthetics-
Hi Kevin, I hope you're in good spirits. <That I am, thank you!> I am sold on the DSB. I was just curious though about the benefits (if any) on a thin layer of sand. Say 1/2 or less. I have read time and time again Steven Pro's view of either 1/2" or less or 3"-4"(for a 35 gallon aquarium). I can hear him saying that "1"-3" is NO MANS LAND for Denitrification, where it is too thick to be aerobic (contains water with oxygen in it) and too thin to be helpfully anoxic". I sometimes can feel his pain/frustration because he has repeated this so many times in the FAQ's, I am sure he and you other guys are getting sick of repeating it. I made a list of Pro's and Con's of DSB Vs SSB for myself and the only reason that I would even consider a Shallow bed is for Aesthetics only. but it's such a significant factor for me to consider. My tank is only 18" high. Going with a DSB would significantly detract from the swimming room of a FOWLR aquarium. <True, but you need not go deeper than 3.5-4"> Would there be more chores involved with as thin layer than a thick layer i.e. cleaning and stirring sand? <Since you're not worried about disturbing anaerobic areas of the bed, stir away!> or is it really about the same in the end as far as the husbandry of the tank goes? <It's not that much different, but you may need to concentrate on other methods of NNR> I guess that the question I really want to ask is "Is considering a fine sugar sand bottom of 1/2" or less really a waste of time or does it significantly contribute to my tank enough to consider a thin <I think you mean thick here> bed?" <Personally, I'll be running DSB's in all future tanks, FOWLR or whatever. A deep live sand bed in an external refugium would serve your denitrification purpose for you, while you could have minimal sand in the tank. Pick up Bob and Anthony's new book Reef Invertebrates. It's one of a few (actually, can't think of any others) that bluntly address the whole sandbed depth thing without coming to a conclusion on what is "best". It's got all the why's and wherefores on any depth.> It is funny, I went to my local Big Al's to look at their CaribSea oolitic sugar size sand and I though I would pick the brain of the manager. I ask his opinion about DSB and how much sand he thought I should put in. guess what he said, "about two inches is all you need". <Ask 50 people, get 49 different answers...> After that I thought to myself, I shouldn't have asked. But I do know what sand to get through that exercise because it was the one sand the he only had one bag left of. <Careful, I can think of plenty of things that are quite popular that you shouldn't be using!> that gave me a pretty good indication that that's the sand experienced hobbyist's are using. Talk to you soon. <I wish you much luck with this tank and I hope I have been of some help. -Kevin> Cheers. Mike Tol

DSB help 10/30/03
I sent the email below back on 10/6.  To date, things have not changed.  My pH still wants to stay at around 8.6....  
<hmmm... not much to worry about. I recommend ph in the range of 8.3-8.6. You are fine where you are at mate. NSW on tropical reefs is 8.45>
I have changed water twice, 100% volume .  Buffering will not bring down the pH. 
<buffering with ALK minerals indeed can only take you higher. No point adding it despite ridiculous marketing claims of a few products>
What can I do? 
<relax... or read a bit more to get a better understanding (comfort) of how pH/ALK works. Do check out some excellent articles on the web by Randy Holmes-Farley>
This tank has been stuck here now for almost 2 months.  I am considering trashing the DSB.
<good heavens... the DSB has little to do with it mate. Even if it did, it has so many great benefits! Please don't make a fine situation bad with a knee-jerk reaction like this>
but if I do, go to a 1 inch bed, I'm not sure whether the pH will come down then either.    I feed the tank regularly, it has cycled completely, NH2, NO2 and NO3 are at zero, algae growth is minimal.....What to do? Thanks, Frank
<relax my friend. Your tank is fine. Perhaps read some of our WWM articles archived like my piece on "understanding Calcium and Alkalinity". Also, see if you can get your hands on a copy of our new book "Reef Invertebrates" which has the most comprehensive (and extensive!) coverage of DSB, live sand, refugiums, etc among many other things in it. Kind regards, Anthony>

Converting to DSB 
>Howdy Crew, 
Howdy, Marina here. 
>I try not bug you guys without first doing my research, but I don't want to blow up a year old marine tank. Here's the situation: 
29 G 
Undergravel with powerheads 
One powerhead with intake sponge on the tank bottom 
>>I assume this is for additional water movement, yes? 
>350 Tetratec HO 
Eheim canister 
Prizm (yes, I know, I have to clean it every other day for it to work) HO skimmer 
2-3" of mostly coarse to medium aragonite and crushed coral substrate 
25lbs of beautifully encrusted Fiji LR. 
Tank inhabitants are: 
3 Damsels 
4 hermits 
1 banded coral shrimp 
and a recently growing population of Aiptasia anemones. 
>>Lovely. 
>I perform bi-monthly 15% water changes (distilled water and Instant Ocean) and change power filter/carbon/PolyFilter every two weeks, maintenance the Eheim every month, but I still have to add buffer to raise pH above 8.2 every couple days. 
>>This is because you're using distilled water, which I'm sure has all the buffering capacity of RO/DI water (that is to say *none*). It really should be buffered BEFORE you even mix the salt. 
>All other, Ammonia/Nitrite/Nitrate/Phosphate read 0. I want convert to DSB for more buffering (I have bought 30lbs) of fine aragonite, but really don't want to capture everyone and pull all the existing substrate and LR out. 
>>Gotcha, but know that if you continue to use the distilled water without buffering before you mix the salt you'll still likely have pH jumps. 
>Is there a way to gradually add the fine substrate to the existing substrate and remove the powerheads from the undergravels? 
>>You wish to remove the undergravel filtration completely, yes? 
>Should I add or remove some of the external mechanical filtration?  
Thanks, Randy R. 
>>Alright, I'm going to assume you wish to convert entirely to a DSB, sans undergravel filtration. You won't need to pull the live rock out, but you'll need to move it so you can remove the undergravel filter plates. This process is going to really stir things up, so I'd be sure to have the canister filter cleaned, ready for a few more quick cleanings with all the detritus that's likely to be stirred up. So, dealing with one side at a time (may be a good idea to allow a week or two in between, just to be safe), remove filter plate, shift present substrate, carefully add wet new sand (rinsed, please!), then shift substrate back over. The more carefully you do this, the better, as you'll disturb your bacterial colonies less. I don't think you'll need to disconnect the canister filter, especially with the lovely Prizm you've got there, but do continue your maintenance schedule with both. Once you've got the deep sand bed in, I assume you know you can't vacuum it as you do an undergravel filter. Know that it can take quite some time for it to become well-established, so the less you can disturb it, the better. Light vacuuming of the CC may be necessary, but not for a while. I hope this has answered your questions, and accept my apologies for the late reply, as the person in whose inbox this was hasn't been able to answer queries lately. Marina

DSB substrate 12/9/03
Hi Bob or Anthony, I love your book! When is the next one out?
<kind thanks... and Vol. 2 (Reef Fishes) will be out in 2004. We hope to have it ready for late summer perhaps>
Is there anything in this hobby other than water which is not controversial?
<good point, although can you please define what you mean by "water" <G>?>
I am planning a DSB for a new 75 gal tank. I was planning on spending $$ for 200 lbs of aragonite until I read Dr. Shimek's papers on substrates. His opinion is that only the particle size (fine) matters and not the composition itself.
<there is merit to this belief IMO and I myself prefer sugar fine aragonite for most applications too (because most folks want/need nitrate control/support)>
I live in SW Fl and have beautiful calcite beach sand which he feels would be just as good.
<depends on what your perspective is. For nitrate control you will need more of it if it is more coarse... and subsequently need better water flow and sand stirring (you or creatures in the tank). And even if it is sugar fine, it will not contribute minerals as well (at all, nearly... none) as aragonite. Aragonite is much better in this category as it dissolves at a pH of still over 8.0... but calcite does not dissolve until the pH dips into the dangerous mid 7's on the pH scale>
He also states that aragonite will not be much of a buffering agent as it does not breakdown until the pH is much lower then it should be. What are your thoughts on this?
<I disagree on the latter. From what I've read in science and hobby literature, aragonite dissolves easily in still higher pH waters (over 8.0) and my practical experience with 48,000 lbs of this sand delivered for my coral farm and used over a decade supports this <G>. Seriously... the half life of sugar fine aragonite is a mere 18-24 months in most aquaria... meaning that your 6" bed will be about 3" deep after 2 years and have contributed so many useful minerals in the process>
Will I have the same results using the local sand assuming all other things are equal?
<good results but not the same. No worries, the mineral loss can be reckoned by more water changes and careful supplementation of your system with calcite instead>
Thank you for you respected opinions.
<thank you for caring to know them my friend... best of luck. Anthony>

DSB substrate II 12/9/03
Anthony, Wow, talk about a fast reply! You and the Crew are great!
<we aim to please... that and we have no social lives and sit by the computer all day. Oh, yeah... we write for a living. Phew... we are not total losers <G>>
The buffering question and at what pH is dissolves seems to be the major difference. But we all know it does dissolve, so those minerals must go somewhere!
<exactly... and many folks (myself included) have noticed that the need to supplement with Calcium and/or buffer is markedly decreased in such systems>
I lean more toward your explanation as you certainly have used
enough of it. I suppose in the overall scheme of things, the price of the aragonite is one of the least.
<yes... true. And it yields so many natural benefits>
I shall plunk down the $$ and buy some!
<have you heard about buying this same material from Home Depot Stores packaged as play sand (formerly South Down brand)?>
(you don't have stock in the sand mine do you? :))
<heehee...nope. Its a rule around here.... we take no free samples and as such can remain unbiased about recommendations/critiques>
Thanks again
<best regards, Anthony>

Building Up a New Deep Sand Bed
Hi guys hope you are well mailing you from South Africa.. Feeling somewhat depressed after our knock out of the cricket world cup (That's if it even exists in the States)
<I can totally sympathize with you. We're no threat in the cricket world, but my friend from Cape Town is in serious depression over this, too...Chin up! Scott F., hoping to cheer you up today!>
Quick Q I currently have a 100g Reef tank with +- 2inches of medium to large crushed coral that has been my sand bed for over a year and is full of nice little critters. I'm purchasing a 125 G tank and am planning on using your deep sand bed method. Should I put my existing sand at the bottom and then my 3 inches of fine sand on top or vice versa and will this size still be ok to use ?
<Well, the "deep sand bed" concept seems to favor a uniform bed of aragonite in the "sugar fine" sand grain size. The uniformity is supposed to foster proper dissolution of nutrient within the sand bed. If I were doing what you're doing, I'd probably distribute some of the existing sandbed material into the new sand bed, to help "kick start" it. The majority of the sand bed should be the fine grained variety to take advantage of the beneficial processes a sandbed is capable. Obviously, you don't want to waste the beneficial life forms that are in your current sand bed, so just try to utilize what you can>
Also my local pet shop has told me of fine sand that is very rich in Calcium and gives off Ca for about 5 years. What is your experience with this and do I still need to add Kalk?
<Well, this sounds like they are describing the Aragonitic sands that are available, like CaribSea's "Aragamax" products. It's true-one of the benefits of a deep sand bed of fine aragonite is that it will provide some dissolution of calcium and other minerals over time. However, I would not consider a deep sand bed a substitute for other methods of calcium supplementation, such as Kalkwasser and/or a calcium reactor>
Thanks guys. Werner Schoeman
<Any time, Werner! Have fun building up that new sand bed...Regards, Scott F>

Goin' Deep (DSB Questions)
Wow Scott, asking that substrate question just opened a larger can of worms.
<Rinse them thoroughly before feeding them to your fish...LOL>
I've been reading over the FAQs re: sand beds all morning and am thoroughly confused.
<Welcome to my world, man!>
First let me tell you more about my setup if I may.  I have a 125g tank with an Ocean Clear Canister filter supplied by a Blueline 1100 gph pump.  I didn't know any better at the time and followed the advice of the LFS to have the tank drilled through the bottom for the intakes and returns (two of each).
<Doesn't sound too bad to me...Can be modified (?) to work with a sump, maybe? Lot's of potential here...>
This is what's making the planning of live rock so difficult.  Trying to figure out how to arrange it and not block the returns.  Both returns are aimed at the surface for surface agitation.  I have also installed two air stones in the back corners for more water movement.  I have a Remora Pro skimmer that produces a couple of cups of dark stinky stuff every couple of days.
<Excellent- dark, stinky skimmate is a thing of beauty!>
I also have an Emperor 400 that I keep carbon and Polyfilter in..
<Polyfilter rocks! Best sure to rotate out the carbon and Poly Filter regularly>
I cut the carbon out of the filter pads and rotate in new clean ones (bleached and dried) with water changes.  I believe
I have at least 10 times water turnover per hour.  I have 120 pounds of crushed coral substrate that is probably close to 2 inches in depth. I think I finally figured out why I had such persistent algae.
< Me, too! You're on to something here...keep going>
Now, I was reading in the DSB FAQs that in FO tanks there can be a lot of detritus accumulation in the sand bed which would fuel algae.
<Well, there certainly can be. However, a well managed deep sand bed (with occasional light stirring/siphoning of only the top 1/2" of sand can avoid any potential problems...You don't want to disturb a DSB>
What would be my best bet? Bleach and reduce the amount of my existing crushed coral, or go with sand.  If I go with sand, since it is fish only, should it be around 1/2 inch deep or go ahead with the 4 inches?
<Well, either would work. I have kept many tanks successfully both ways. Take also into account the kinds of fishes that you are keeping. If you are a Goatfish or Dragon Wrasse fan, or keep other fishes which dig  deeply into the sand bed, this may not be such a good idea. I kind of like the DSB look, some people don't like the aesthetics of the "ant farm" effect that a DSB can show. Frankly, I would go with the DSB. When used in conjunction with regular water changes, filter media replacement (really important in a system designed around largely mechanical filter systems), and overall good husbandry techniques, you should be fine.
Sorry to keep bothering you on this holiday weekend.
<Believe me, man- not a problem! Your talking to a guy who gets excited about making twice weekly water changes and cleaning his skimmer regularly...Glad to be of service!>
Thanks again for all of you help. Vince
<Any time, Vince! Have fun, whichever route you choose! Regards, Scott F>

Depth of DSB 7/7/03
First, Anthony and Bob; I'm enjoying your new book. A lot of very interesting reading. Anthony, thanks for the inscription.
<very welcome my friend... thank you :)>
In it you bring up that 3 inches of sugar size sand is the min. for NNR. Do you have any studies that back that up? Want to know for when I am talking to people about their tanks.
<Dr Rob Toonen has released some prelim data on such matters... will have full report soon I hear. Other data exists (some of the original work) from French academic aquarists in France dating back to the late 1980's/early 1990's (Jaubert, Ounais). To be honest though... I'm really speaking from a decade of practical experience. I used 48,000 lbs of the sugar fine aragonite sand for my mariculture facility. Heehee... this combined with similar reports from colleagues led me/us to the statements>
The other question is about the "half-life" of 18 to 24 months you bring up on page 36. I've not seen that in any of my tanks with aragonite DSBs.
<indeed... 'tis because of the commonly variable pH that works in the favor of aquarists in this case (not dissolving the sand consistently/fast enough... but at the expense of dissolved bio-minerals)>
I have a number of tanks with 3 or more inches of aragonite that are 2 to 3 years old and do not seem to show that in any of them.
<without a Ca reactor, such tanks usually do not have fast coral growth either (scleractinians). No worries at any rate>
Could this be caused by having too many borrowing detritivores or animals like pistol shrimp? Thanks, Ray Pollett
<no my friend... really just a matter of adequate water flow and various faculties to dissolve the material. A matter of grain size too if larger. Kind regards, Anthony>

Re: Deep sand bed
Dear Anthony, Thanks for your advice again.
I just came across articles about the combination of tribased pelletized carbon and "right now" bacteria as a fast means for denitrification. What's experience or views about this?
<the industry has seen many such products with miracle claims for more than 20 years... <<Longer than this... RMF>> one hasn't panned out yet. The very nature of denitrification in an anoxic environment cannot be bottled, liquefied or pelletized. I'd be very surprised if they work if this is their claim. Quite frankly... DSB is so simple, effective and proven (not to mention inexpensive!) I have no desire to pursue another method currently. DSB is my strong advice for denitrification>
Regards TFChow
<best regards, Anthony>

Clumping sand
Anthony, Ughh.  C'mon, buddy, yer killin' me.  I set this tank up in January, so I honestly do not remember (with 100% certainty) which brand I used, but all of the local LFS's carry CaribSea, and I purchased my substrate locally -- and yes, it is medium grade.
<indeed... this is a common complaint>
Also, my substrate depth is less than 3",
<heehee... that's what I get paid the big bucks for <G>. Not a surprise here either>
but I CANNOT stand the "ant farm look" of reef tanks with 4" - 5" substrate depths.  I'm sorry, but I find it *very* ugly.  
<Your aesthetic preference is valid. If you do not like the look of a DSB then you simply need to find some other way to manage nitrates. No biggie. Which do you hate more... DSB or weekly  water changes (or more)... perhaps less fish... whatever it takes. Its your tank. However, 1-3" sand is not an option IMO. It takes way too much effort to keep from clumping or becoming a nutrient sink. 1-3" sand is not deep enough for denitrification, yet too deep for aerobic faculties. It just sucks in the long run (2+ years). Especially with medium or course grains: Traps a lot of detritus, requires massive water flow in the tank and weekly siphoning of the gravel, so to speak. To other people though, this is of little trouble. Personal preference.>
I used 60 lbs. of aragonite in my 75 gallon tank, about 1.5 - 2 inches deep overall.
<Ughhh>
Why is depth of substrate a possible mitigating factor for this particular problem?
<penetration (course grains and not too deep) of spiked water in a low pH environment where fusing can occur more easily (calcite has to hit 7.6 or lower to begin dissolving but aragonite can do so at 8.3!>
Would adding 20 lbs. of a another brand or type (fine Fiji pink, for example) help me any?
<nope... the grains will settle... might make it worse (no ideal medium for a given faculty to exploit to the fullest>
The number of seemingly innocuous pitfalls that this hobby possesses is truly amazing.
<very well stated my friend>
Anyway, one of your statements: "You were dosing slow enough, but perhaps the concentration in the slurry was too rich. It is a simple matter of too much or too fast." was encouraging.  I will work on 'tweaking' my dosing speed and/or concentration.  In the mean time, any thoughts on how to address the substrate *quality* issue would be greatly appreciated; but I won't increase the depth substantially.  
<no worries... if you can otherwise control nitrate accumulation, I'd recommend siphoning sand out periodically until you get to no more than 1/2" depth. At this point with good water flow in the tank you will not have to service it much anymore>
I apologize for being stubborn on this one point, but I really think that the "ant farm look" is quite unattractive.
< no worries at all. We all have our preferences. You might consider an inline bucket full of sand downstream and out of sight for DSB nitrate control if necessary>
I am, as always, very grateful for your time and consideration.
<our great pleasure>
Your fellow hobbyist (with concrete slab substrate), Mark Schwartz
<with kind regards, Anthony>

Nitrates reduced by Deep Sand Beds (DSB) - 2/11/03
Wow!  I didn't expect it to work that quick!  
<yep... literally 2 weeks for most proper deep sand  beds (4" or more)>
My nitrates were 80ppm for months no matter what I did (FO tank) and I converted from CC to DSB last week, and they're already down to 20ppm... how very cool!
<good to hear, my friend!>
Thanks for the great website and advice!
<our pleasure>
Now I just have to remember to keep it stirred!  (Not shaken  heh heh)
<or seek active detritivores>
David
<best regards, Anthony>

Fact, Fiction, And Nutrient Export...
I am in the process of setting up a new tank. A 135 gallon Floribbean biotype.
<That should be cool! I'm envisioning the "eye candy" in this reef already! Scott F. with you here today!>
Not necessarily a full blown reef in the true sense but their will be a fair amount of gorgonians as well as whatever life comes on the gulf rock. Is 90 lbs. enough rock for bio filtration or do I need more?
<I think that this is enough rock, for the most part. If you maintain a deep sand bed, this will provide significant biological filtration/denitrification, as well>
Now to my main questions. Their seems to be a lot of contrasting opinions and conflicts as I reed through your FAQ's.
<Well, much like in the hobby at large- everyone at WWM has their own interpretation of many aspects of reef husbandry...You have to take any and all advice with "a grain of salt", and draw your own conclusion in the end...>
1) Sand bed: Bob Smith said he prefers a 1/2" shallow sand bed. Yet others swear by 4-5 inch bed with a plenum. I would rather save the time and expense and use a 1" bed. But would this provide significant denitrification as well as enough depth for some of the Caribbean wrasses I intend to keep?
<Actually, there really is little disagreement and a lot of fact on this topic. The rule of thumb with sand is 1/2" or less, or 3" or more. One half-inch of sand is not enough to provide denitrification; neither is anything less than three inches. Sand beds between 1/2 inch and less than three inches are more or less a biological "no man's land", not deep enough to reduce nitrate, but too deep to be aerobic. This will result in the formation of the dreaded "nutrient sink", which has the potential to create long-term nutrient accumulation and the resulting nuisance algae blooms that accompany it. My advice- Go with a 4-6 inch bed>  
2) Sump: Do your prefer an "in line" Ecosystem type setup, or leaving a standard sump in place and using the refugium in a separate closed loop?
<Actually, in my opinion, a refugium should be supplied with raw water from the aquarium or sump, so you certainly could have a dedicated pump just for the refugium...many ways to accomplish the same thing...>
3) Size: Bob Fenner has made reference to the largest sump possible. Yet when I look around many configs. Most only have a mud area the equivalent of 10-15 gallons. What gives?
<There are so many variables here... I'm not going to try to interpret what Bob meant (well- yeah, I am!), but he correctly points out that a larger sump gives you many benefits, among them the ability to create larger "mud" chambers (if you're into the "mud" thing), provide room for protein skimmers, mechanical/chemical media, and simply add to the overall system volume...Think about it: A 100 gallon tank with a 30 gallon sump is essentially a 130 gallon system (well- almost, because you wouldn't run a sump "filled to the brim" at all times..), so you get the picture here...As Anthony likes to say- "Dilution is the solution to pollution...More water is a good thing!>
4) Plants: I recently read a published article stating that mangrove filtration is not as effective as first thought.
<Mangroves really grow to slow to be considered an effective, rapid means of nutrient export in closed systems. they offer other advantages, such as their leaves contributing to beneficial microorganism growth and their roots offering shelter and spawning areas for a variety of different animals. A cool addition to a display, but I would not view them as a viable nutrient export system>
On the other hand their is now information that Caulerpa produces chemicals that can be harmful to corals.
<Very true...Caulerpa does produce a number of substances which can create problems for corals in closed systems, has a propensity to "go sexual" (releasing it's reproductive products into the water column, degrading water quality), and is just plain "aggressive", often overtaking and smothering more desirable animals with it's rapid growth. That's why my personal favorites are more "purposeful" macroalgae, such as Chaetomorpha and Gracilaria. They are more "stable", grow rapidly, are not overly invasive, and are easy to harvest. All in all, they are much better macro algae for nutrient export purposes>
As you can see about the only thing I can find clarity on is a flow rate of 3 - 5x mud sump area.
<Well, like I said before- everyone has an opinion...What works for me may seem absurd for you...But you need to be able to sort through "facts" and "opinions"...never an easy process, but all part of the fun of this awesome hobby of ours!>
I am hoping you guys can help make sense of this as you always seem to do.
Forever grateful, Ken
<Hey Ken- I'm glad that you turned to us...Feel free to contact us again any time! Can't wait to see how your system turns out! Regards, Scott F>

Triggers and Sand Beds?
All of your responses have been extremely helpful to me so far.  Keep up the good work.
<Glad to help!>
A few more questions.
<Sure...>
Question 1
Is there a Trigger species that I could house in this 90 gallon for the long term?
<Honestly-none. Sure, it can be done, but I think it's not such a good idea>
If none, then what species or type of trigger would work in this tank if bought small (1.5 inches) and then eventually put in a larger system (180 gallons)?
<Many of the triggers available would be fine, with the exception of the truly larger (like the Niger and "Titan" triggers, etc) species...The more "reasonably sized ones" (max of 9-10 inches) could stay in this setup for a couple of years, if you start them as juveniles, IMO...but they do grow fast!>
And, how many years could he live in the 90?
<Maximum of one or two years, depending on the other inhabitants, feeding, etc>
Question 2
All of that crushed coral gravel (aragonite based) that I have in my tank was bought under the assumption that it would be the best choice for a tank with a trigger in it.  Can a DSB work with this messy eater?
<Well, not with the "detritivorous species, such as the Odonus, Balistes, Balistoides, and Rhinecanthus species. Definitely more possible with the Xanthichthys species, like the Crosshatch Trigger, Blue Chin, and Sargassum Triggers. These are much more "reef compatible", and usually are planktivorous in nature; less likely to dig up a sand bed...Let's face it, though- a trigger is a trigger...anything can happen...Hope for the best, be prepared for the worst...>
I was under the assumption that it wouldn't because the trigger would eat all of the necessary critters that live in the sand.
<Entirely likely with most of the more commonly available species>  
Also, how do you vacuum the sand to get rid of detritus? (The detritus that would presumably accumulate because the critters that eat it would themselves be eaten by the trigger)
<With a true DSB, you really want to avoid disturbing the bed as much as possible. If it makes you feel better, you can siphon maybe the top 1/2 inch or so...>
I have spent much time perusing your site, and although I have learned much, I still cannot arm myself with enough info to make a good decision here. A detailed explanation here would be much appreciated.  Thank-you.
<Well- once again, the concept of a deep sand bed and a trigger together is essentially a roll of the dice! It certainly can work with some species, but it can also backfire miserably...Unfortunately- it's your call on this one!>
Question 3
If I do keep the crushed coral,  is 4 - 5 inches a good amount?  Or should I just have 1 inch?
<I personally would use an extremely shallow layer (like 1/2 inch or less with this stuff...Unlike the finer aragonite substrates, this stuff can become a serious nutrient trap over time, especially if kept at a 3-5 inch depth...Yes- it can, and has been done by many people...but I wouldn't do it. Why not just a sprinkling of fine sand, like CaribSea's "Aragamax Sugar-Sized" oolithic sand? It looks nice and can be easy to keep clean in a 1/2" depth.>
Question 4
I have heard that if you have less then 4 square feet of space for a DSB it is worthless.  You might recall my other questions about a refugium, 36 inches deep, 13 inch by 20 inch footprint.  Would an 8 inch DSB be worthwhile in this refugium?
<Honestly, I have not heard that argument before. If you're talking about a 5000 gallon tank, then I'd agree that 4 square feet of DSB would have minimal impact. However, with a deep sand bed, the much more important issue is the depth...$ inches or more, with a maximum of around 10 inches (frankly, I'd quit at 8" myself. These depths can most readily foster the necessary beneficial processes occurring in the DSB>
Question 5
I know you have answered questions on this previously, but tell my please if I have this correct.  Above mentioned refugium with 8 inch DSB (not live sand) 50 lbs of LR suspended above the sand by PVC and egg crate (will eventually make the sand live).  Will this cause any problems if I do not buy critters to stir or slowly move the sand?  Do I have to do any maintenance in this set-up or is it a set-up and forget about it sort of procedure?  Can this refugium stay running like this maintenance free for years?  (I have heard horror stories of DSB causing noxious chemical releases in aquariums)
<Well, in my opinion, I would not call a DSB or refugium completely "maintenance free", but I suppose that minimal attention is acceptable. There are, of course, lots of differences of opinion on this... As far as sand-stirring creatures are concerned, many of the more commonly used creatures actually tend to decimate the very processes we work so hard to achieve...Perhaps a few snails and maybe, maybe, a small brittle star...but that is fine, in my opinion. Unless the aragonite absolutely turns into a "brick" over time, I don't see the danger of not stirring it...again- perhaps just stirring the top layer would be fine. And, yes-inert materials will become "live" after a brief period of time. You may want to check out sand bed expert Bob Goemans' great site, saltcorner.com, for more information on sand beds (although Bob favors the plenum approach, a number of the dynamics are similar in a "non-plenum" equipped sand bed...>
Thanks again for all of your advice.
<Any time! Hope I was helpful! Regards, Scott F>

DSB in main tank
Hi Bob!
Why do you recommend placing the DSB in a sump vs. in the Display tank?
<Yes... either>
I've searched your site to no avail for the answer (the DSB Article is a blank page, and it's not addressed in the FAQ's).
<Needs to be written, added, thanks. <Is now> Read these files on refugiums: http://www.wetwebmedia.com/refugium.htm and beyond>
I am (slowly) setting up a 92 corner tank-the sump will be a 20 gal.15"dia. x 24"h Hex (or, if I could house an in-sump skimmer, maybe two, one for a refugium w/ DSB & macroalgae and one for equipment ---those are all that will fit under cabinet). Do you feel it would be worth it to include a DSB with such a small footprint?
<Mmm, yes... and perhaps a good hang on skimmer would do here... My selection input on WWM.>
Thank You! Erik Nelson
P.S. Saw a "Yellowtailed Moray" the other day @ the LFS. It gave me the "eye". Any opinions on this species? I know you recommend the non-piscivore(?) eels, but I really would like to keep cleaner shrimp alongside one.
<Mmm, maybe take a look through our coverage on muraenids: http://www.wetwebmedia.com/morays.htm and fishbase.org
Don't know this common name.>
P.P.S. My wife says that eels "turn her on". WOW!
<Wow indeed! Be chatting, Bob Fenner>

Retrofit of a DSB and Protein Skimming
Hello there... it's been a while since my last question, and once again, I would like to thank you in advance for taking the time.
<You are welcome.>
My nitrates are at around 100, which isn't too bad because it's a FOWLR, but nonetheless, I want them controlled for the happiness of my fish.
<Good, it would be better for their overall health to have the nitrates lower.>
My 100G tank has a 40G Rubbermaid sump that holds a TF1000 protein skimmer. The main tank has about 90lbs of LR and only a 1" layer of fine LS. My family of fish include:
Naso lituratus - Naso Tang - 5.5"
Rhinecanthus aculeatus - Picasso Trigger - 3.5"
Balistoides conspicillum - Clown Trigger - 3.5"
Premnas biaculeatus - Maroon Clown - 1.5"
Diodon holocanthus Linnaeus - Porcupine Puffer - 3.5"
Here are my questions:
1) Can I simply add in more