Re: New Reef Setup, Regarding substrate   9/11/07 
Dear Bob,
Thanks for the response.
I need some advice on the initial setup areas.
I am trying to use my existing tank instead of tearing it apart and building a new one ($$ waste $$) this tank is a 4.5'L X 2'D X 2.5'H bow-front.
This tank is running (far below potential I must say) as of now from last 1 year.
I plan to revamp this rather than spend on a new tank.
Regarding substrate -
Can I have the following layers: UGF (not functional) + base rock buried in crushed coral + 2-3" fine beach sand?
<Better to have more or less... Please read here: http://www.wetwebmedia.com/dsbdepth.htm
and the linked files above>
I expect that the sand would fill in all the gaps that exist in the crushed coral and base rock and remaining would be a layer over the top.
Would this cause any problems?
<Possibly, yes...>
Reason for this layering is to raise the substrate by a few inches and reduce water column depth (30" currently) to facilitate reach ability for maintenance and light penetration.
<All gets mixed eventually... unless you install a screen of sorts... as you'll find by reading...>
Looking forward to your opinion :)
Thanks Again
Ranjith
<Welcome! Bob Fenner>

BB Reef! Substrate y/n  6/7/07
Guys!
<Hello>
Just a short sweet question? Is it better to keep a bare bottom Reef than having the coral sand below it? Thanks in advance.
Regards
<While there is a lot of arguing on many of the reef forums, I much prefer a sand bed, both for how it looks and what advantages it offers. This does not necessarily mean a DSB, although that is what I use. A shallow sand bed, less than 1 inch, also can work.>
<Chris>

Please could you offer me some opinion over the use of sand in my reef aquarium?   - 04/27/06
Hello WWM crew,
<Good evening Bob, Jen here.>
                         Please could you offer me some opinion over the use of sand in my reef aquarium?
<Sure!>
On setting up I had a purely cosmetic, (although I'm sure slightly beneficial), thin scattering of coral sand on the aquarium base. Detritus build up has meant that I have removed most of this as it seemed easier maintenance wise and coralline algae has since colonized the glass improving its bare look. I live in an area of soft water here in the UK and have recently been having buffering issues,( not helped by a faulty pH meter).
<Understand that one.>
Now it has been suggested by my LFS and some fish keeping friends that my chosen brand of salt is one possible contributing factor to this problem,
<Could be, depends on the mix.>
( KH had dropped to 5 and pH 7.6), but use of a reef buffer has brought things back to a more healthy level,( KH 10, pH 8.2). It was also suggested that adding a 1" to 2" bed of sand would help prevent recurrence of this problem, that and a new pH meter!), but I am concerned at the detritus problem becoming an issue again. Will a deeper bed of sand and the accompanying clean up crew if purchased,( conches, sand sifting stars etc), help prevent build up of detritus?
<I personally am a proponent of sand beds, and sometimes DSB in the reef set up.  I would suggest that about 2 inches and then the addition of the appropriate clean up crew would help you with the issue.  Remember to include many critters that will stir the bed and aerate it, also those who may consume detritus.>
I'm basically after your collected insights as to whether sand is the way to go, and if so which type and how deep?
<This would be personal preference.  I would suggest aragonite mix approximately 2-3 inches deep; deeper if you wish.>
The tank is 340 liters after displacement by the 45 kg of live rock within. Its 60 cm deep, 45 cm wide and 150 cm long. The
system has been running since last June.
              Thank you in advance for your help.
<You’re very welcome, good luck with this.  Jen S.>
                                   Bob Mehen, Cornwall, UK.

Making A Stand With Sand (Sandbed Composition)
Hi,
<Hi, Scott F. here with you tonight.>
I've had a 125G marine tank setup for about 2 years.  Initially it was going to be a FOWLR. A few months into it I discovered that two other engineers at work have reef tanks.  I made the "mistake" of talking to them and looking at some pictures of their tanks.
My focus quickly shifted to converting it to a reef tank.  I love it.  I've been reading books, magazines and internet info. pretty steadily for the last 1 ½ years now.  If I had it to do over again I would have done quite a few things differently.  Learning is fun and expensive.
<Yup, I know how that can be!>
I upgraded the lighting last year and have upgraded water flow and a new skimmer this year.  The next step that I would like to take is to increase the depth of my sand bed.  I have a few quick questions about how to pull this off without causing harm to the fish and corals that I already have.
<Sure, glad to help.>
My first question concerns what size sand to add.  I currently have about 1.5 inches of aragonite sand (1 - 1.7mm grain size).  Should I add more of this size, or go to something smaller?
<Well, it all depends on what you want to accomplish.  A finer sand have been proven to denitrify quite effectively.>
I'm not sure how risky it is to mix sizes.  I've read differing opinions on this.  If I do stick with this size, how deep should I go?
<As you read through your own research, there are varying opinions.  I mix sand sizes in my tank and it seems to work out ok.  It has not proven problematic for me.  As far as depth of your sandbed, my rule of thumb is one-half inch or less, or three inches or more (up to six inches, or so)>
Secondly, how do I add it?  Is it better to add a little at a time, or try to get the new stuff underneath the existing?  Either way should be a challenge.
<Personally, I have added it all at one time and have not experienced any problems.  Your water may be cloudy, but will clear in several days.  Monitor your water chemistry carefully.>
Thanks for your help.
Larry
<No problem Larry.  I hope this information has been useful for you.>
P.S. I'm reading Anthony and Bob's new Reef Invertebrates book.  It's great!
<It is a great resource and, as a matter of fact, has a tremendous amount of research on sandbeds.>

Sand Bed Query
Hi, you have been so helpful l in the past and I was hoping that you could help with another problem. I have a 29 gallon reef tank that has been up and running for about 10 months or so. Everything is going fine the fish seem to be happy and healthy. The problem is my sand. I have 30 pounds of live aragonite Fiji pink sand and it's turning colors. First is was that ugly brown diatom algae that was growing all over everything. Now that has turned to green algae on the glass and my sand is turning red. I tried to sift the sand myself to keep the top layer from turning colors, but that wasn't working to well. I even brought 3 sand sifting star fish hoping they would do the trick. But so far very little progress. The red is in clumps and it's in the back of my tank. The front is still kind of brown. do you think it's from my light? I have a Current USA Orbit Compact fluorescent with the moon light. They say that the bulbs are 65watts each, dual daylight & dual actinic. Do you think that could be the problem? If not what could be doing this. The tank looks so much brighter when the sand is white. Please Help
>>>Hey Heather,
First of all, fairly new reef tanks sometimes do this, no worries really. Secondly, have you taken steps to introduce sand bed fauna into your tank? I like to grab a few pounds of "grunge" off the bottom of the live rock bin at the LFS. Sand bed kits are also available online. Without the needed critters, a sand bed will not function properly. Also, have you checked your nitrate and phosphate levels? How much do you feed? Are you running a skimmer? Have you done any water changes recently? How is the current in your tank? Is this fine or course sand? It should be fine, almost sugar-like. Larger grains can be present in smaller amounts. All things to consider.
Regards
Jim<<<

Large and Fine Live Sand
I have a 75 gallon reef tank that has a deep sand however the grain size is not fine but medium.  I read that the most effective size is a "sugar fine" grain size. I have live rock several brain corals, a hammer, a frogspawn, a leather, mushroom, green polyps, xenia --- fish include a Purple tang, Lawnmower blenny and a Red-lipped blenny.  My water parameters are in range except for my nitrates which is the reason I am inquiring about the deep sand bed.  My primary question is will it be effective to mix fine grain with my already existing medium grain.
<Yes, but I would try as many inches of the sand you currently have (4-5) first... measuring nitrate at least weekly... and see how this works out. Bob Fenner>

BARE BOTTOM REEF?
Hey WWM, <IanB on call tonight>
A question about substrates for marine tanks.  I would prefer to have no substrate to eliminate the greatest amount of trapped particulate matter as possible,<Bad idea> yet am not sure about the negative impacts on marine life.<do read http://www.wetwebmedia.com/deepsandbeds.htm>
<http://www.wetwebmedia.com/marine/setup/filtration/biological/biofiltr.htm>
I understand the question is still contestable, but considering I wish to keep anemones, polyps, Amphiprion ocellaris and tube worms, is it advisable to go with the "bare bottom" approach,<definitely NO> or will a light scattering of aragonite sand really improve the hospitality factor of the tank to its inmates ???<again read through http://www.wetwebmedia.com/deepsandbeds.htm>
Thank you in advance for your time
Andrew Hough <your welcome, IanB>

Substrate - Reef System
Hello to All at WetWeb,
<Hi Peggy, Don here tonight>
Am adding a 6" sand bed (Aragamax sugar-fine) to my existing 72-gallon reef.  Is it necessary to remove all rock before adding the substrate?  I have a ribbon worm residing in a big piece of base rock, and I hate to mess with it if not absolutely necessary--hard on him for sure and on me because he's quite large and creeps me out when he slithers throughout the rock, especially if the rock's in my hand during removal!!:)  Also, any ideas on the best way to add new sugar-fine substrate to an existing system without having one massive cloud in the tank--especially considering it'll be about 140 lbs of sand to get a deep bed?
<I would not remove the rock as it is more stable sitting on the hard bottom than atop 6" of sand that is 'dynamic' and always changing/moving. Get a high flow pump and a couple trash cans/tubs that are food safe. Pump the water into the cans removing the inhabitants along the way. Then pour in the new sand and pump the water back in. Viola! All done with no cloud.>
Many tanks (bet you haven't' heard that one before, uh??),
<tee hee, good one.>
Peggy
P.S.  Love the new book--I'm wearing it out already!!!!!!!!
<Yes, another invaluable resource, eh? Will pass along. Don>

Substrate and beginner questions - 8/26/03
Hi All...
Love your site. I'm learning a lot. <Fantastic to hear> This is my first saltwater tank. <very well> I have a 29 gallon fish only so far tank with live rock and live aragonite sand for the substrate. When I was doing the initial set-up one LFS told me I would need 30 to 40 lbs live sand for substrate and around a pound of live rock per gallon.  I went out and bought about 40 lbs live cured rock for the tank and then added 40 lbs sand. My question: is this too much substrate? <It is best to look at it in inches. I (we) recommend about 4-5 inches in substrate depth. Check this out: http://www.wetwebmedia.com/deepsandbeds.htm and check out all of the blue links as well. Lots of good reasons to have a deep sand bed.> I've seen many forums that say only 1 or 2 inches of substrate should be in the tank. <HIGHLY disagree>  If it's not too much, what should I do in terms of keeping it healthy? <Every six months to a year add a scoop of live sand from either another reefer or a local fish store. Many places online also sell live sand like www.ipsf.com>  I currently have 1 red fire shrimp, a cleaner shrimp, a peppermint shrimp, 4 hermit crabs, 2 clowns, 1 purple Dottyback, 1 yellow tang and a yellowtail damsel. <A very high fish load for such a small tank.....> Ammonia, nitrates, and nitrites are all zero. <For now.....Keep up your water changes> We would like to have a sea star and maybe an urchin but don't know what kind to get. <Be sure to research before adding any animal. Urchins and starfish tend to have a varied diet. Be sure to research your choices very thoroughly before purchase. It is a moral imperative.> We see those chocolate chip stars in the LFS around here a lot but I would like to have a red one if possible. <There are beautiful red serpent stars and brittle stars that are quite beneficial to the aquarium as they tend to eat the fallen and uneaten food leftover or missed by your fish. They tend to be a little hardier and forgiving. -Paul>
Thanks so much for your input.
Carla

Crushed Coral versus sand
Hi
<<Good Day to You!>>
I am new at marine set ups.  I have a 65 gallon marine aquarium.  I have 80 lbs of crushed coral in the tank.  However, on reading most articles including your FAQ I notice that sand seems to be the choice of all of you.  I plan to get the live rock soon and am just trying to get the salinity and ph working first.  My question is, is there a difference in using the crushed coral and if so, will it work for the reef tank that I eventually want to have running?
KC.
<< As you have read, a deep, sugar fine, sand bed is the recommended solution at this time. This does not have to be in the main tank. You can setup a deep sand bed (DSB) in a sump or in a refugium, both of which will make your life easier in the long run. If you don't have a sump/refuge then 4-6 inches in the main tank would be recommended by most. The reason for this are many, but the crushed coral is at least going to be a detritus (fish gunk) trap and you don't want to go there!
Don >>

He Digs Fish That Don't Dig!
This will be a SPS tank with strong lighting and brisk water flow. what I don't want is sand sifters in this tank. My 55 still has my first fish in it and I am fed up with this relocation of what ever they see fit. These are damsels that like to dig. I just want things to stay put . Most of my rock in my 125 are large pieces to give me a more open sand look but still achieve a reef. I assume a little sifting is good???
<Well, some people even siphon the upper 1/2 inch or so of their DSB's, or employ animals like brittle stars and sea cucumbers to do the work. Either way, many of the beneficial "infauna" that reside in the sand are destroyed or disrupted.>
But digging like an inch or two is not.
<Correct, digging deep into the substrate can cause a major disruption to the nitrification process occurring in the sand bed> Can you give me an idea? Best tang? Yellow, Purple, or the Copper?
<Well, it all depends on what you want the tang for (i.e; algae control, or just plain enjoyment, or both..), and what his/her companions will be. My all-around choice of the species that you listed (BTW- I don't know what a "Copper" Tang is...?) is the Yellow Tang-Generally hardy, adaptable, easy to feed, sociable, and peaceful.>
What about blennies? I would like to occupy all levels-mid, upper, and lower levels of the water column.
<Well- there is a huge variety of blennies to choose from. You can include the Meiacanthus ("fang blennies"), which are mid water swimmers, the "Sailfin" blennies, which tend to swim throughout the water column, and the "grazing" type blennies, such as the "lawnmower" blennies, which tend to stick to the bottom of the tank. All can do very well, provide reasonable variety, color, and interest, and most stay smaller (less than 4 inches). And the ones I mentioned don't dig! Really good choices for reef tanks, IMO>
Thank you
<And thank YOU- for stopping by! Regards,  Scott F.>

Substrate
WWM Crew, First I would like to thank you for answering all of my questions quickly and efficiently. My 120gal. fish only tank is recently undergoing changes to become a reef tank as they are much more challenging and rewarding.  So far I have added more live rock, (approximately 90 total lbs. and will hopefully end up around 130lbs.when another shipment arrives.)330 watts of actinic lighting and 110 watts of daylight lighting, Amiracle wet/dry filter with Mag return pump, (I forgot the model but it pushes about 400gal/h.) and one Maxi-Jet 1200 powerhead but I'm waiting for the other one to arrive.  I am also trying to put money aside for a high volume protein skimmer but a firefighter's salary isn't exactly luxurious.
<I'm a teacher by day. HA!>
I currently have an undergravel filter plate with approximately 1 1/2" of crushed coral on top (recipe for disaster).
<Yep>
I want to add a fine grain live sand but I don't know if I should put it on top of the plenum and coral or remove all of it and only have sand.
<If you're going shallow, go very shallow. Like 1/2 inch with no UGF or gravel underneath. Just a 1/2" sand bed>
Now for my second question: Deep sand bed or a Berlin style "sprinkling"?
<If I were redoing my sand bed, I would build and install a plenum system and I wouldn't use UGF filter plates for this purpose. Author Bob Goeman's offers convincing evidence of plenum effectiveness>
Do fine grain sand beds require vacuuming or only a simple water change?
<Always vaccum out any obvious detritus that is sitting on any sand bed>
I know I cheated and asked three questions instead of one but it would be greatly appreciated if you could help me out.
<You got my ideas! Hope that I've helped. David Dowless>
Thank you.

Pure Aragonite Sand - 2/23/03
I have read Dr. Shimek and 1300+ Southdown posts. <Makes a man out of ya> Do you have any experience with  "Pure Caribbean Aragonite from Petroglyph"? "Grain sizes vary from 0.18 to 1.2mm, perfect for reef systems." Allegedly oolitic. <Actually, I use Nature's Ocean oolitic in my 30g Indo Pacific lagoon tank. A little expensive but I really like the results.> They sponsor some web sites. <Yes, very good about supporting the industry.> I would be having it shipped in and need about 280lbs. <are you doing a 4 to 5 inch deep sand bed?> I have Googled your site with no luck. <Hmmm.......you're right don't see it anywhere........in any event I am sure it is a fine product. Check out the many aquarium forums and see if anyone is using it in their tanks. Get some opinions/reviews. In any event, I like their aquarium calculator tool for finding the pounds needed for sand bed depth in an aquarium. Good site overall. Thanks for the link. Paul>
http://www.purearagonite.com/facts.html

Just a little sand? - 3/10/2003
Hi - a really quick question:
<Ok.  Scott V. here with a quick answer>
I have a 75 gallon set-up with 75lbs of live rock (Fiji and Bali), running a Remora Pro, carbon, power heads, etc.  I have a percula and a three stripe damsel (some hermit crabs), and am still stocking the tank.  I want to add a Tang, maybe Gobies.  I would also like to add some inverts down the road.
My question is, I received some advice and have about 3/4" of Tahitian Moon Black Sand as substrate.  Now, this is not aragonite - do I need to add live sand, or an aragonite based substrate?  
<I would replace entirely, but in this case is more dependent on what you desire as the end result>
Will the Tahitian Moon cause any problems in my tank?
<Not directly.  I believe that sand is silicate free so it should not directly cause any problems.  However, with ¾” you are adding no benefit either, while detritus can accumulate in the sand resulting in nitrate problems.  The higher nitrates will result in having to scrape algae much more frequently, which is something we all enjoy so much.  There is also no benefit in maintaining the Ph and calcium levels.  I would remove as much as you possibly can and replace it with aragonite, as either a deep sand bed or plenum.  In http://www.wetwebmedia.com/marine/setup/index.htm , under “Gear/Components” you will find links to FAQ’s on both Deep Sand Bed and plenum set ups.>
Thanks for the help,
<No problem, and enjoy!   Scott V.   >
Jason

DSB or Crush Coral in a Reef tank
Howdy Guys,
<Hi Annette, Don here tonight. >
I have searched your website for a clear cut answer to whether I should convert my 75 gallon cc substrate to a sb or DSB.  
<Wow, if you find any clear cut answers in the hobby/obsession, let me know will ya? >
My plans is to have reef/fish system.  The bioload will be at it's limit with fish.  This is the plan for fish; 1 fire goby, 1 yellow tang, 1 flame angel, 1 regal tang, 1-2 common clowns, 1 royal Gramma, 1 algae blenny.  As for corals and such I don't plan on having any real delicate specimens.  Starfish, mushrooms, anemones, maybe an open brain coral are some possibilities.
<Hmm, the tangs will need a lot of territory and may become aggressive with each other and other inhabitants>
This is my problem I cannot decide if I should convert to a sb or DSB with these specimens.  I read somewhere that a DSB has a tendency to accumulate wastes but also heard that it helps with nitrates unless a high fish bioload is present.  I am very religious with cleaning about every 8-10 days with a 10 gallon water change.  Currently we have an Eheim filter, lg. protein skimmer, power heads, and will be purchasing a UV sterilizer and about 75 lbs of live rock.
<All sounds good!>
Any direction on what to do would be very helpful.
<I believe that with the addition of corals the DSB advantages will outweigh the disadvantages. You may need some additional cleanup, burrowing snails will help with this. I am having good luck with Nassarius and Cerith. At least in the sugar fine sand, the matter 'sits' and doesn't get trapped in the substrate. If you decide not to go with the DSB, a sugar fine bed of less than 1" would be the other option. The CC (crushed coral) traps a lot of 'gunk' Hope this helps, Don>
Thanks,
Annette

DSB or Crush Coral in a Reef tank
Hey Don,
Thanks for the quick reply.  
<No problem>
Hopefully I will have good luck with the Tangs, what you mentioned has been a concern of mine too.  I am still waiting for the availability of a good regal tang specimen, hard to find.  We saw one today at the LFS and it was badly beaten up and was constantly running into things, plus it had very bad color (Ick maybe).  Could you believe he would sell it for $45, normally $90, I wouldn't even pay $5 for a fish that looked that bad.
<Very wise, too many folks buy a fish that looks 'healthy' even though others in the same tank are obviously diseased. Or, believe they can nurse it back to health. I your case, it would have been silly. Kudos>
        Just to let you know for people who are looking for good fish at a good cost tell them to check out Saltwaterfish.com.  I have had outstanding luck with them.  The fish arrive healthy with gorgeous colors and no nipped
fins plus they have a 6 day guaranty. and free shipping on orders over $75. The draw back is some fish are not constantly stocked like my Regal Tang. They also carry corals and invert. plus live sand and rock with free shipping.
<Stay the course, buy healthy livestock and you are on your way to a lot of fun! Don>
Thanks Annette

Substrate
Hi Bob, Steve, and Anthony,
I've been looking over the FAQ's on substrate and somewhat confused still. I am building a reef tank. I'll eventually be getting live rock among fish and corals. I just recently bought and placed CaribSea Aragonite Special Grade Reef Sand (1-2mm in size ) inside the tank about 2" deep (44 gal corner...no water yet inside). I did read from Steve(?) that he had this substrate and was not happy.
<Yes, it was I that wrote I have that sand and am not happy with it.>
My question is this, just short of buying something else, how deep should this be exactly. I've read from 1/2" up to 4". I'm worried about the toxic pockets that may be produced if there is too little
or not enough of aragonite. I also read about placing a screen mesh over a portion with another layer on top.
<This is probably your best option. Use fiberglass screen for windows from a hardware store. On top of that, I would add another 2" of very fine grade sand.>
Not too familiar with that nor what that does exactly.
<The fine grade of sand is better for critters to live. Having inoculated my sand over a half dozen times, this particular grain size does not seem to encourage worms or much of anything else. The other benefit of the fine sand is it stops detritus from settling between the grains of sand.>
Also, is it necessary to place a small amount of live sand on top of the aragonite.
<It is nice for inoculation, but you could also use your liverock.>
Thanks for all the help. Mike from Cleveland
<You are welcome. -Steven Pro>

How much live sand?
Great incredibly informative website.
<Thank you from all of us.>
I'm setting up my tank (reef) for the first time since the great Northridge Earthquake with the following parameters:
60 gallon Aquasystem with built in wet dry
<You may want to consider removing the W/D media.>
Fluval 304 canister filter (ceramic media removed)
90lbs live Fiji rock (in 2nd week of curing)
Remora Pro protein skimmer
One Powerhead
Lighting ?? (2 fluorescent and 2 Blue actinic) I can't remember the name but I purchased from Marks Tropical Fish in Studio City.
My question is this: How much live sand should I have? 1.5"? 3"?
<For reef tanks, I prefer to use a 4-6" deep sand bed, DSB.>
Is live sand better than Aragamite?
<Live sand is generally seeded aragonite sand. I usually use almost all dry sand which I seed with liverock and/or some livesand. I would purchase the livesand that is not already prepackaged.>
Which would you prefer?
<See above notes.>
Darrin from Sherman Oaks, California
<Good luck to you. -Steven Pro>

Aragonite's Impact on pH and Nitrates
Steven,
I just went to the LFS and purchased 20 lbs. of the 'Natural Ocean
Bio-Active Live Aragonite Reef Sand'. Is this a good product, how does it
rate?
<I have never used the product myself. We have Southdown in such abundance in Pittsburgh that I have little experience with anything else. As long as it is sugar fine grain size, it should be ok. FYI, I do not put much faith in any livesand that comes prepackaged in a bag and sits on a dry goods shelf.>
I am hoping this will reduce the nitrates and maintain pH in my 180
gallon fish only setup.
<Twenty pounds is going to be hard pressed to do anything in a 180 gallon tank.>
I have 2 connected sumps, the second sump has the return pump and skimmer.
<If you can, the skimmer would operate far better if you had it receive raw tank water, pre-W/D filtered.>
The first sump is the Wet/Dry with about 12 X 12 inches extra space. Where's the best place for me to lay down a sandbed and how thick should I make the substrate?
<Wherever you can place it and 4-6" thick.>
I have Caulerpa in there just sitting in the water but it has not grown much. Any help would be great!
<Having the Caulerpa attach to grow would help.>
Thanks again, Chris
<You are welcome. -Steven Pro>

Marine Substrate
Dear Anthony, Steve, or Bob:
I have a 65 gallon reef tank with approximately 100 lbs LR and has about 3" of crushed coral substrate on the bottom. The tank dimension is 48"L x 24"T x 12"W. As you can see the tank is quite narrow. Only ½ of the substrate is exposed, the rest is under the rock. All the information I got from your website suggests a substrate of crushed coral just not the way to go due to its tendency to trap debris. Based on the suggestion, last week I went out got few bags of topical play sand by Southdown.
<Lucky you to live in an area with Southdown.>
I know the best way to go is to replace all crushed corals with sand however, it just too much hassle with all the LR, coral, and fishes.
<And the preferred way.>
The easiest way is to vacuum the ½ exposed crashed corals trying to get out as mush debris as possible then gradually add about 2" of sand on top of the crushed corals let it filled the gap.
<A bad idea.>
The more difficult way is to take out the ½ exposed crashed corals (by vacuum?) and replace with 5" of sand.
<Better, but you might as well bite the bullet and do it all.>
I like to have your opinion as which ways is more beneficial without put too much stress on the inhabitants.
<If done right, removing everything and adding a new DSB should not be too stressful for you or your fish. First, mix up some new water, maybe 20 gallons. Then, siphon off clean water into a bunch of buckets. Then remove the liverock into more buckets. Catch the fish as you can and place them into the buckets of clean, old water. Scoop out all the crushed coral. Add the new sand and then liverock. Next, slowly pour the old water back into the tank, taking care not to disturb the sand too much. Add your fish and then top off with as much new water as needed.>
As always appreciate your expertise. Thank you. Wayne
<You are welcome. -Steven Pro>

Substrate/Alkalinity Q's
Cheers, Anthony or Steven.
I'm sure Bob is having a great time in Cozumel, I have snorkeled there myself a few times, I would live to go diving there but when I go more then a few feet under water it feels like my head is going to explode.
<I feel the same way about Alk questions... now what was your question.. Oh, riiiiiight <G>
Anyways I was hoping to get your guys opinion on the substrate I was planning to change. Currently I have about 3 inches of crushed coral (mistake # 1), 
<oh, ya... detritus pit>
I see what you guys mean by detritus trap. So before placing my live rock, I siphoned really well and removed about 2 1/2 inches of the cc where I placed the rock, so there's about 1/2 inch or less under/around the rock. 
<Very good!>
The rock was placed last Sunday and I did a water change last night and the cc around the rock was almost as dirty as the 3 inch section of the tank. 
<hmmm... shouldn't be that bad>
I fed the fishes very little during this time period, my water flow isn't great but I don't think it to be that terrible either. 
<ahh... most people drastically underestimate the need for current. In a fish only tank 6-10X is minimum... with reef and live rock displays you need MUCH more. I have about 1500gph in my 50 gall reef and is barely looks like I have moderate flow!>
After I minus the head pressure, flow is approx. 1500 gph on a 125 gal FOWLR. 
<yes... not bad at all... may just need to be more strategically adjusted>
I just want to get this substrate/depth thing correct because I have another 45lbs curing right now and am going to order another 90lbs in the next few weeks and don't want to have to disassemble the rockwork every week to siphon the cc. I have since gotten 100lbs of fine oolitic sand by E.S.V. I couldn't even guess on the grain size but I would definitely say it is finer than sugar. 
<excellent... I like the grain and brand just fine>
This is where I am totally stumped, it seems like everyone is in agreement here in not having a DSB in a heavily stocked tank with messy eaters as mine. 
<is it more challenging as much as I love DSB>
The label on the sand states it can provide denitrification in as little as 1.5 inch depth 
<I disagree that this happens in many tanks... more often than not no>
but I fear this depth is too much for my tank. BTW tank mates are vol. lion, wolf eel/Dottyback-not sure witch is the proper name, niger trigger, yellow tang, Naso tang. 
<the eel is the only one that will stir the pot too much>
Do you agree with removing the cc and going with the fine sand at a depth of a 1/2 inch or less? 
<the 1/2 of sand is fine once you get the water flow adjusted or upgraded. You should have enough flow so that detritus stays suspended and is carried to the skimmer(s)>
If you guys agree with the sand should I first place the rock on bare bottom and then pour sand around the rock or sand first then rock on top? 
<that's how it would be done>
I currently have 90lbs Fiji rock, is it ok to add another 90lbs Kaelini rock or just stick with another 90 lbs of Fiji? 
<your call>
One more thing if I may? I have currently seen my ph rise from the 8.1/8.15 to the 8.25 range or better just from aerating over night and mixing salt for a day or two in advance. 
<excellent>
Currently using the Kold Sterile system and then I aerate the new water overnight, it then reaches a ph of 8.35 and alk of 4.9DKH, 
<very low alk>
I then add salt, no buffer and 24hrs later readings are ph 8.22-8.25, alk 16.8DKH. 
I have the Kold Sterile plumbed so that it could precede the tap water purifier/DI to lower my alkalinity, could I just mix up 20 gal of the Kold Sterile water and then 20 gal of the Kold Sterile water followed by the tap water purifier DI and then I should be able to reconstitute the water to more appropriate values?
<more appropriate for what?>
I have yet to use the twp with the Kold Sterile but when I used just the twp I was lucky to get 30 gallons and got sick of replacing them. I still have a cartridge left over from about six months ago that was only used for about 5 gallons and it is still damp inside, is it safe to reuse this cartridge? 
<yes>
Calcium after a water change is about 380 but I refuse to use any calcium supplements until it reaches 350 for fear of this snow storming event I seen a lot about since my alk is on the high side. I really value your guys advice, thanks so much. Mike
<the alk is a bit high if it lingers long... but the Ca under 400 and the alk slightly over 12dKH is fine and can continue if consistent through regular water changes. Both levels should not me max high but one at a time is safe. best regards, Anthony>

Setting Up Live Sand
How do I put my live sand in my new tank? The water is already in and circulating in tank and sump. I am concerned that it will get suspended in water and get in sump and skimmer and filters.
<<Not to worry, turn off circulation, release sand at bottom. Turn it on and let er' rip! Only very fine particulates will be suspended and be skimmed/filtered out or settle. If settling in sump bothers you (most are designed to trap particulates) then vacuum that out. Remove any vegetative matter etc. from screens, filters, powerheads. Be happy! Craig>> 

Tank question
Good Afternoon,
I looked on your site but didn't find the answer to this question. I am trying to decide on a substrate to use for my 40 gallon breeder tank for saltwater. I currently have a 20 gallon high saltwater tank that is doing really well. I have dolomite as a substrate, no live rock, 2 external aqua clear filters and an air supply. All of my levels are stable in this tank and the fish are doing quite well but I am going to a little bigger tank. 
<I am glad this system has worked well for you, but I do have some suggestions. Dolomite is a poor buffer because it only dissolves at very low pH. Aragonite or coral based substrates work much better. Also, if dolomite does dissolve, it is very high in magnesium which can be a problem. Also, I always strongly recommend live rock, even for fish only systems. Power, trickle and canister filters are expensive, maintenance intensive and don't control nitrate. Live rock is also expensive, but requires little or no maintenance and controls nitrate. Also, unlike artificial or non-living decor', live rock never needs to be cleaned!>
I'm seeing all of this talk about crushed coral and sand (DSB). The dolomite in my tank is working well but a lot of dirt accumulates in it. I do regular water changes once a week and siphon the gravel. I would like to possibly add sand to the tank,
<My rule of thumb for sand in tanks is to use one of three options: No sand, coarse and shallow (4-5mm or larger grain size, not more than 3/4" deep), or fine and deep (1mm or smaller grain size and 3" minimum deep). All sand will trap detritus, so the idea is to be able to get it out or for the critters living in the substrate to process it. Larger grain sizes allow easy siphoning and critters to live between the grains. Fine sands allow critters to burrow and don't let detritus penetrate, giving large animals time to eat it. Deep, fine beds of sand also are capable of processing huge amounts of nitrate. Grain sizes from about 1-4mm are the worst of all worlds... they are hard to vacuum and very few critters are able to live in it. Whatever you choose, I would recommend that you use at least 50% aragonite or coral based substrate.>
but I am not interested in having live rock in my tank. I had a 55 gallon before and all of the bugs were horrible and overrunning my tank with live rock, especially the bristle worms. They were everywhere and even in my filters. Once we broke down that tank and sold it, I found a bristle worm that was close to 6 inches long. I can only imagine how long it would have been stretched out. NICE!!!!! NOT!!!! That freaking sucker hurts when they get you!!!!!! 
<I understand some peoples aversion to bugs and worms, but I am such a fan of these animals, I feel like you just insulted my mother! All of these "bugs and worms" were cleaning your aquarium for you! Bristleworms are generally harmless, and only occur in large numbers when the system is overfed and/or allows detritus to accumulate. Properly fed systems with strong water movement and an occasional "rock dusting" rarely have large numbers of bristle worms. I strongly encourage you to consider live rock and the free labor force that comes with it!><<Mmm, RMF disagrees, as will anyone who has been stuck but good by some of these fireworms... their notopodia can have very sharp elements indeed>>
Anyway, could I still have sand in my 40 gallon tank without the creepy crawly things? I just want fish and a nice looking tank. Would I be able to go into the tank for the water changes and stir up the sand a bit to clean it???? What would you suggest??? Or should I just go with the crushed coral and stick to my weekly water changes and siphoning for the new tank???? 
<My suggestion is to welcome the creepy crawly things! However, if you just can't do it, I would suggest a thin layer of coarse Aragonite or crushed coral substrate that gets vacuumed often. This will give you the aesthetics and allow you to remove wastes.>
I know that live rock is a good thing, or so they say, but after my bug experience, I want no parts of it ever again. Thank you very much for your time. Your website is terrific!!!! Jennifer 
<Best Regards, and I hope you will give live rock another chance! AdamC.> 

Questions Regarding sand bed and fish compatibility
Let me start off by saying sorry for such a long post here.
<No worries>
Hi, Bob this is my first question to you and I am sure will not be the last. I have been reefing for about 2 years and I have to say on a skill bar I would give myself a 3.5 out of 10. That being said here is my tank info. I am setting up (transferring from a 46 bow with crushed coral 3.5 to 4" in depth to a 75 drilled and I am going with sand "SouthDown" I am going to go with a 1.5" depth.
Equipment is as follows:
Lighting 2ea 250watt MH 10K
4ea 24" VHO 2 Actinic White and 2 Super Actinic
Filtration
Wet-dry (I will probably not use this or just use it as a remote power head for water movement)
Canister (for carbon and nitrate sponge).
Chiller Aqualogic Drop in 1/4hp
29 Gallon sump Mag 18 as a return
CPR HOB Fuge (I am planning on a DSB with macro and LR Rubble).
Water movement Tunze 6060
Live Rock 80-90 lbs.
Skimmer Euro Reef 5-2
Calcium Reactor Still shopping for one
Controller Medusa
<Lots of nice gear>
My 46 was/is over stocked and nitrates were higher than I like. I am pretty sure the crushed coral has something to do with this as it traps a lot of detritus and even though I have a huge clean up crew and do regular water changes and vacuum it is still higher that normal and I want to go over to sand.
Livestock Purple fire fish, 2 Maroon clowns, Yellow tang (probably going to give/sell him) Coral beauty and Flame angel, Scooter Blenny and Lawnmower blenny. All the fish are under 2.5 and as they get bigger I will probably need to replace them with smaller ones. Two clams and 2 BTA's (1 red 1 green) along with the clean up crew I wrote of above. I keep pretty much just hard corals and 1 or 2 softies. I am going to also get 3-4 Shaving brush plants for not only looks but also function in the main tank. 
I will be adding two of my favorite fish down the road they are Laboutei Fairy Wrasse & a Geometric Pygmy Hawk. 
My questions: 
#1) I cannot put a deep sand bed inside my sump due to my skimmer, chiller, and return pump will be in there and I am not sure if they would be harmed by sucking up sand and there is really no way to separate the sump. So would the HOB Fuge with DSB and macro be enough along with the Shaving plants in the main tank?
<Should be>
Or not enough to even bother with?
<Well worth bothering with>
My goal with the fuge is for nitrate control and also a place for critters (pods and such to grow and reproduce) 
<Will indeed help with all these>
#2) Do you see any problems with the 2 fish I plan on adding down the road with the current livestock I have now.
<No... but will about "top off" this volume system>
All the fish I have now have been in the tank for about 1.5 years with no problems getting along or nipping corals or my clams.
Thanks for you time and if you see anything that I am missing or need to correct please let me know.
Thank you 
Bruce
<Do set up the two systems in parallel for a while if you can, be careful re new additions, quarantine incoming livestock... you should do fine... I foresee a much larger upgrade in your future... perhaps some dive, adventure travel... Bob Fenner> 

Substrate/Sand beds confusion 1/19/04
Dear Bob, Anthony & Staff,
<cheers... Moe in the middle>
After getting advice from my LFS. I started to take out all of my substrate which was live sand about an inch thick. They told me to have either 4" or nothing at all.
<any sand depth can be made to work, my friend, with adequate water flow above it and sand stirring.
Now I'm down to about a 1/4" in the tank but it starting to clump up and has that dirty look to it. I have a lot of current in the tank and when I tried adding more it looks like I'm going to blow my corals off the rock.
<the problem is not that you have too much flow, but rather that it is not diffused adequately (you have limited laminar outputs from a water pump or your powerheads). Do a keyword search for "Goodbye Powerheads" to make a closed loop manifold to better distribute water flow>
My problem is at this point I'm frustrated and am not sure if I did the right thing by taking all that sand out. I would like to add sand to the tank to make a deep sand bed but I think the right way to it would be to remove all the rock first. It has taken me a year to get things really going and I'm worried that if I take that rock out and add the DSB how my fish and corals would hold up? I was also thinking if I can leave the rock in and pour from 4" in the front to nothing in the back?
I'm confused on what type of sand to use after reading this statement.
"Live Sand: Is the latest and not-so greatest sub-specialty in "reef" keeping. Though this stuff has lots of microbes, it also presence many potential problems. Introduction of pests, parasites and pollutants not the least of them. Unless you're utilizing very little (a few grains thick) of this stuff, be wary of it going anaerobic. Keep your eye on it for dark spots"
<the above statement is remarkably ignorant (as in uninformed) and incorrect>
I have made many improvements to my tank with the help from your web site. Thanks again!
<all good my friend... and please do consider reading our coverage on DSBs, living substrates, etc. in "Reef Invertebrates" - it is comprehensive if I may say so. Anthony>