Playing In The Sand (Pt. 2)
Scott:
<At your service!>
PVC idea worked great!  Easy as pie!  Boy that sand looks a million times better than the coral rubble... course it looks a little weird at the moment as only half the tank is done - kinda like a beachfront almost
<Hey- nothing wrong with that! LOL>
- I went somewhere between 4 and 5 inches in depth... Looking forward to next week!
<Yep- take it slow...You'll appreciate the results of being patient>
(One week is enough time to allow the sand to become "live"?)
<I think a week between "additions" of sand should be okay. You may want to "juice it up" a bit by adding some healthy live sand from a reliable LFS>
Thanks heaps!
<My pleasure! Good luck with your new sand bed!>

Aragonite sand  - 2/15/03
HI Bob ,
<Anthony Calfo in your service>
Is Southdown sand considered fine sand? <yes... sugar-fine oolitic/aragonite> and is it good to use for a DSB. <the best in my opinion at 4-6" or more>
I have a fifty five gallon tank with about 3 inches of Southdown sand.
<That would be the minimum for efficient denitrification IMO>
Some corner areas are turning black . Is this normal ?
<Yes, likely... unless you notice a sulfur smell (rotten eggs) which often indicates a lack of good water flow and/or stirring in the tank>
.Tank has been running for 4 months.   
<Ahhh... no worries, the tank is too young to go anaerobic without extreme neglect (not likely here). The coloration between the glass in sand is limited to that thin film/area and is from indirect light causing dark algae>
I was going to raise this to 5 inches this weekend . Do you think this is a good idea or should i leave it the way it is and get more sand sifters?
<Both if the sand sifters are hardy (like bullet/dragon gobies or blue-spotted yellow watchman gobies>
Thanks  Chris
<best regards, Anthony>

Substrate depth/marine
Hello Mr. Fenner,
One last question, hehehehe.....
Flying Fish Express suggests that I purchase about 90lbs (3") of substrate for a 55 gallon tank, preferably Aragonite (or 60% Aragonite and 40% live sand). I think I remember reading on your site that a 1" of substrate will do fine (that's if you don't have a UGF). What do you recommend?
thanks,
Greg
<The one inch will be fine. Bob Fenner>

Southdown vs. other sands - 2/21/03
Sorry to bother you again <no problem.> I've got a local ace hardware mere blocks from my house and my question is this IS there a difference or something special about the Southdown play sand that makes it preferable to other "play sands" the ace near my house carries their own brand of play sand, could this be used just the same? <Not the same type of sand by a long shot. Please look through the wetweb google search tool as this topic has been covered many times here. Use Southdown as the keyword. There is some really great information there. I would not use the Ace Hardware over the counter play sand, if it were me.>  It's $2.99 per bag, not that that's relevant LOL.<Yeah......it's just money! Who cares about that?!? Paul>

Re: Southdown vs. other sands - 2/21/03
ok thanks, <my pleasure> I will have to get some from the shop then, as the home depot near me doesn't carry the Southdown. <yeah, same here. Are you on the West Coast? This stuff is mined in Florida and seems to only be distributed on the East Coast for the most part. Of course, there are always exceptions to the rule. Sorry to hear that Southdown is not available in your area. Check out the links from the search. Interesting stuff there. You can always see if someone can freight it for you. Check around the forums here and at other sites as sometimes it is offered there. Good luck! Paul>

Substrate depth on new tank
Hi guys,
<Hi Greg, Don here today>
I have a quick question regarding Marine Substrate? I've got a 55 gallon tank with about 45lbs. of live rock and about a 2" layer of Aragonite across the bottom. Is this too much? Is it too late to remove some of the sand? The tank has been cycling for about 2 weeks now. Also, would it be beneficial to place the live rocks on some eggcrate? Thanks in advance.
<Well the recommendation is for less than 1" or more that 4". You do not say what the end game is here so some assumptions have been made. Since the tank is brand new, I think I would remove some substrate and try to sell it to a fish buddy, or save it to replace your substrate down the road (store dry and as air tight as possible). This may add a week or so to the cycle process, but remember: good things are worth waiting for. I do not believe it is necessary to put the rock on eggcrate for long term. Don>
Regards,
Greg

Crushed Coral Depth?
I have had my SW tank for 9 months and have been adding live rock (now 52lbs in a 55 gal tank). Reading your web site and others this past week I became concerned that my 55 lbs (Carib Sea, Florida, 5-10 mm) crushed coral substrate was too thick (approx 1.5 - 2 inches) - I am not using an UGF and the articles mentioned to keep the substrate to 0.5 - 0.75 inches in this case as it mentioned a couple of gases that can develop that are toxic to
the inhabitants (fish and corals).  This morning I read an article on your site that encouraged a thick bed (see excerpt below):
Substrate question
I have about a 2.5 inch bed of crush coral in my 55 gallon
tank. I want to add another inch of Flamingo Pink on top of the crush coral, is this OK or will it kill a lot of my biological in my crushed coral? Also would the Flamingo Pink be ok with gobies (stirrers). Thanks, Jim >> Should be okay... density, size wise of the new/old substrates... with the gobies as well... but will the two mixing together be okay with you lookswise? They will. Bob Fenner
QUESTION: Can you please tell me what the best approach is as I am very confused on how thick the substrate should be.
<Well, there are lots of different opinions here. The prevailing thought is that sandbeds (or gravel beds) under 3 inches in depth are too deep to be fully aerobic, and too shallow to foster complete denitrification processes. With coarse substrates, such as crushed coral, there is the added concern of detritus accumulation. With proper substrate maintenance, and the possible inclusion of sandbed "stirring" animals, this type of bed can be successful...just keep an eye on things>
I am also sharing the rest of my setup for any general comments/feedback:
55 gallon
52 lbs live rock and crushed coral substrate
Magnum 350 Canister with 2 BioWheels
(2) MaxiJet 1200 and (1) PowerSweep 228
Coralife Power Compacts 260W (Actinic and Daylight)
Skimmer - Prizm
Supplements: SeaChem - Calcium +3 (Saturday), Buff (Sunday), Trace
(Tuesday), and Vita (Thursday)
Feed only frozen foods (varied)
QUESTION: SeaChem Reef Success Calcium +3 is easy to add, but is this a Calcium Chloride rather than Calcium Hydroxide?  Should this concern me enough to change this to something else (Kalkwasser, B-Ionic, Kalk, etc.)? What do you recommend?
<Not familiar with this particular product, although I think SeaChem makes some excellent ones. You may want to contact them regarding the specifics of the product's application>
Livestock: Rabbitfish, 2-Percula Clown, 1-Purple Firefish, and 1-4 stripe Damsel
Janitors: Serpent Star, 2-Emerald and 2-Red leg Crabs, 11-Snails (Astrea, Bumble Bee, Turbo, Margarita)
I will start to add coral over next few months and a Mandarin Goby in another 3- 6 months.
<I'd avoid the mandarin altogether in this tank, to be perfectly honest. To many competitive feeders. Although I commend you on holding back on adding the fish until your tank is further established, I think that it's really a fish that needs a setup dedicated to its specific needs and dietary preferences (like amphipods and copepods)...>
QUESTION: Any feedback you have on this setup and the direction I am going in will be greatly appreciated.
<Sounds okay so far. You didn't mention anything about maintenance procedures...I'd utilize smaller (5% twice weekly) water changes in this tank, to really get to nutrients before they have the chance to accumulate and degrade the water quality. Also, you may question yourself on te use of the vitamin and trace element additions...If you are conducting regular water changes, you are usually replenishing these substances in the process. If misused, these products can lead to nuisance algae blooms. Finally, make sure that the skimmer is cranking out at least a couple of cups of dark, yucky stuff a week>
Thanks for all your help - both with the questions above as well as your extremely informative web site - it is a tremendous service to the hobby!
<So glad you find it useful! It's our pleasure to be here for you! Keep reading and learning, and enjoy your tank! Regards, Scott F>

Substrate
A real quick ?
The dude at the fishy store told me the best substrate is sand with perhaps a small amount of live sand in my 75 gallon tank.  Right now I have 1/2 crushed coral and 1/2 crushed Aruba Puka shell.  He said that this may cause a problem with Nitrites...is this true?  Should I go with sand?  If so - how deep?
Thanks for your help!
Jeff Wagner
<Please read here: http://www.wetwebmedia.com/marsubstr.htm
and the linked pages (in blue, above) re your questions. Bob Fenner>

Make A Sand Decision
Hi Bob, I wanted to get your opinion on the great sand debate.
<Actually, Scott F. here today>
I have read dozens of opinions on using normal play box sand from HD (by Paragon), all negative.  However, not one of these people admits to ever having tried it, they just all "know" it's bad.  Do you have direct experience with this or a similar product?  It seems ridiculous not to use it if it's actually OK and only "folklore" is stopping us.  What do you think?
<Well, there may be some merit to the opinions. I personally have not used this product, but I have used the infamous "Southdown" play sand, and it works quite well. It is an Aragonitic product, and provides a lot of good benefits (calcium supplementation, proper grain size for denitrification, etc). I have heard that many regular play sand products contain a lot of impurities, ranging from metals to silicates, so what appears to be a great "bargain", could actually be an expensive mistake! Do check with the manufacturer, if possible, as they may be able to give you some idea as to the composition of the sand. Hope this helps! Scott F>

Substrate
Hi guys, Bryan here, it has been awhile. I have a few questions. First is regarding substrate. Setting up a 75 gallon FOWLR. In the main tank am going to add 1/2"-1" of Carib sea Arag. sand. Adding a 20 gal tank under the stand for a DSB w/ more LR. Is it alright to use the sand for a DSB or better to use s/t like special grade reef?
<Better to use the fine grade of sand. I have the Special Reef Grade and do not like it/do not recommend it.>
Also I read on the F&Q that I can set up the 20 gal refugium w/ DSB and LR w/o any lighting. Is this fine if I decide to go this route?
<Yes, is fine for cryptic animals (sponges, etc.) but adding lighting would diversify the refugium.>
Last question. I am looking for egg crate to go into my sump and can't seem to find any. If you have any suggestions please let me know.
<Most any hardware store. It is used for overhead fluorescent lighting fixtures.>
Thanks Bryan.
<You are welcome. -Steven Pro>

Re: Sand & Stars
Hi, thanks for your prompt answer.
<<Hello, you are quite welcome.>>
In your mail you said that "perhaps it's time to put a little more sand..." but Anthony says "5 inches or more or 1" or less... right now I have a 1/2" - 1 1/4" from the front to the back of my tank...
<<I had to call Anthony on the phone to make sure we both sing the same song. To clarify without putting words in his mouth, it is his observation that an inch or less is a zero-sum; no harm, no benefit. In between one and three inches is certain disaster - the sand bed will be neither anoxic or anaerobic. Something between 3 and 6 inches is best advised - three is great, four is better, five even better and so on.>>
So I think I will run for a Brittle star... (one? two? <<depending on the size, one, perhaps two, no more.>> my tank is a 200 ltr with sump) My actual animal inventory is: 1 damsel yellow tail, 1 damsel
blue devil, 1 tang, 4-5 blue legged hermits, 4 Turbo snails, 2 little peppermint shrimp, 1 banded shrimp. nothing will fight with the Brittlestar?? <<There aren't many things that 'fight' with brittle stars, the seastar would bail out rather than fight.>>
Thanks again. Carlos
<<You are quite welcome. Cheers, J -- >>

Crushed coral to sand
Hi Bob and thanks for your info on my copper problem...here's another one for you. I just decided today that since I'm going to have to get rid of my copper filled crushed coral, 
<very wise>
to upgrade some and I have a question for ya. I purchased a Amiracle wet/dry filter and am going to get rid of my under gravel filter and go with a sand bed. How thick should I go with the Arag-alive sand. 
<IMO the so-called "live" bagged sand is quite unnecessary if for no other reason than price. At best it has bacteria in it... does that mean the sand simply wasn't washed before it was bagged? It certainly doesn't have zooplankton, polychaete worms and most of the things that aquarists regard as desirable components of live sand. For that you can get a handful (literally) of live sand from an established aquarium (LFS, aquarium society member, friend, etc) to inoculate a bed of cheap dry sand and all will become live very well in as little as two weeks for a lot less money (and not supporting a misleading practice)>
I have two tanks I'm going to do this with...the first being a 110 gal and the other a 55 gal.
Thanks Robert
<the depth of the sand depends on your purpose and the livestock kept. Small fishes and reef aquaria where denitrification is desired will want more than 3 inches (ideally 5+) of sugar fine media (like Southdown sand from Home Depot... see message boards). For large fishes, messy fish or frisky foraging/burrowing animals the sand bed may need to be rather shallow (1/2 inch) and denitrification accomplished through other means including extra water changes. Best regards, Anthony>

Southdown Sand
Which Home Depots have Southdown sand. Home Depot near me do not. RGibson
<<Greetings Ralph... Home Depot has a ridiculous number of stores around the country and there's just no way for us here at WetWebMedia to keep a tally of who keeps Southdown sand in stock. Your best bet would be to either ask this question of Home Depot directly or perhaps pose this question on our forum, http://wetwebfotos.com/talk where you can get a diverse set of opinions. Cheers, J -- >>

Lava Rock and other stuff.
Hello guys, how are you today?
<very well, my friend... I hope you are well too!>
I'm setting up a 60 Gallon Marine Tank. It will measure 123 Cm. x 51 Cm. x 36 Cm. I will put two 40 watt bulbs (1 actinic and 1 daylight) and I'm planning on making my own sump instead of buying a Tidepool 2. The pump I will be using is a MagDrive 1250GPH. ( I think this will be enough)
<indeed enough water flow but perhaps add more daylight tubes in the future for light>
I found two bags of lava rocks in my house, you know, those used for the charbroilers? I already boiled them in water and now I have them in a plastic box with salt water, an air diffuser and some Stress Zyme each day, to colonize the bacteria on them.
<whoa!... don't put them in the tank and don't bother buying such enzyme products at all... rather a waster of money for most>
Today, a friend told me that lava rocks are the worst for marine aquariums, because they have heavy metals and toxins. Is this true? 
<yes... it may very well be true. Indeed some risk involved here since lava is volcanically formed. I would never recommend it. Carbonate material is always better>
I even have a very good book that tells me that they are the best. 
<I wouldn't be surprised if it is the CIG series... a poor and inaccurate reference>
I'm only planning to put them in one of the media bays in the sump, because in the aquarium I'm planning to put normal live rock. What should I do? What is the best biological filter for the sump?
<if you use it... I don't think it is likely to kill animals, but may impart nutrients for a terrible nuisance algae bloom>
What can you tell me about the bed? What kind of sand should I use and how deep?
<less than 1/2" if just for aesthetics, 4+inches of sugar fine aragonite sand if you want denitrification>
Is the SEACLONE skimmer good? 
<it has a BAD reputation with aquarists>
I live in Venezuela, and stuff here is very expensive. This skimmer that in the US costs $99, here costs $230. 
<my goodness! Many folks here wouldn't even take it for free let alone pay good money for it! What other brands are available to you?>
Is it possible to put it in the sump?
<there are many models that can go in the sump>
My LFS tells me that keeping the salinity at 1.019 will keep the Ich off and other parasites and the fish live happy. Is this OK??? 
<it is OK but not exactly true... the lower salinity is more favorable to the fishes and less favorable to the parasites, but there is no guarantee that it will prevent Ich. My friend, you really must have a small quarantine tank to all new fish, rock and invertebrates in first. Please read through our WetWebMedia site for advice on QT protocol... it is critical to success. Please never put a new animal directly into your tank from a LFS or anywhere!>
what are your suggestions?
Thank you very much for your time. Julio Grossmann
<with kind regards, Anthony>

I was born to Rubble
What a great crew. You have one of the best jobs in the world.
<Yes, agreed... does not feel like a job at all>
You didn't drive to/from Dallas did you? Damn, if you did and I had known, I  would have asked you to pick up my fish tank I have in storage there. :)
<Ha! Did drive... and would have picked up (was some 400 pounds lighter on the return>
Sigh. What did you leave in Dallas?
<Four hundred pounds of Korallith, some calcium reactors and books mainly>
When you have time, if you can dig around for pictures that show the Firefish  environment I would love to see them!
<Mmm, good question... maybe I can use your request as a springboard for a column...>
Oooh, a rubble zone article -- yes, yes, yes!!!
<Call me Barney (Rubble!)>
Okay, here are some questions:
How deep should the rubble be? Should it be just a single layer, or towards the back of the tank should rubble be put on top of each other for several layers?
<Large, chunky bits on top... finer materials down first>
Do different soft corals grow near each other there or is it rather sparse?
<Mixed... some species near, most are spaced a width of a colony apart or more>
If only one softie should be included, should it be only one coral that is allowed to grow huge, or should it get fragged and put in several different spots in the tank?
<Depends... on what you want to do (culture, cuttings), but do start all smallish, spaced apart>
Should the softie (colt, finger, toad stool, whichever it is) be on a bigger
piece of live rock, or should it be on the very bottom of the tank, getting a foot hold in the rubble?
<Species dependent as well as what you want to look at.>
Okay, if I read correctly last night, you think an inch or two of sand covered with rubble would not cause Cyano or algae. Wouldn't it be a nutrient trap because debris would get caught and then decay in the sand rubble?
<Not much... in a vivacious growing system, there is little nutrient to uptake>
You could always try staying up all night and then all day...
<Too old... have memories that used to be able to when I was a pup... but  probably just dreamed that bit up. Bob F>
I know I could do that ten years ago!
MM
<Ha! Make that your age back for me. Bob>

Rubble Zone Tank
Hi Bob,
<Hello Madison>
How was your Indo trip and MACNA?
<Fabulous on the first, and just back and shaky from driving to and fro to/from MACNA... it was very nice>
I've been thinking about the rubble zone tank... I'm not sure if it can work.
<Why not?>
If I take 1" of sand and then throw in rubble found in dealers tanks and hammer live rock into little pieces to create rubble over the bottom of the aquarium, what would be my biological filter.
<Yes...>
Not the sand, it will not be a DSB. A DSB would not work with rubble everywhere, it needs to be open. There would not be as much live rock as in most other tanks, so the rock isn't going to do it.
If I did it this way, would I just be creating a great environment for algae blooms and Cyanobacteria to thrive in?
<Not likely>
If I didn't put the rubble in and went with a 4 - 6" DSB, well, it  wouldn't be a rubble zone anymore.
Any thoughts on making a rubble zone work?
<As they say in the Nike ads, "just do it"... am sure the rubble by itself and likely with deep sand would be fine>
Do you still have jet lag?
<You are like myself... "para" sympathetic, yes... still not "caught up"... and suffering for it. BF>
MM

South Down Sand
Dear Steven Pro,
Thank you for your quick response! One Last question, today I purchased 8 bags of the Home Depot Southdown sand and once home, I noticed the following changes as underscored.
Soft Texture
Sterilized
Silica Free
Not recommended to traction or aquarium use
Everything else is identical including the SKU. Are you aware of this change and should I be concerned about the statement saying that it's not recommended for aquarium use.
<I have eight bags myself sitting in the garage, so I went out and looked them over for the disclaimers you have seen. Mine only say that the sand has been sterilized. The silica free statement is a good thing. I have no idea what soft texture is, but the "not for aquarium use" sounds to me like a legal disclaimer or something they added to appease the other companies that sell/market their sand. I would not worry about it. I do not remember if I mentioned it previously, but I would sift the sand. I have found pieces of quartz rock in the sand. Southdown packages a lot of other materials for landscape use and there is a possibility of other things slipping in. Again, nothing to be too worried about. The stuff is so cheap, any potential risk is far outweighed, IMO.>
Thanks again, Ron Allard
<You are welcome. -Steven Pro>

DSB substrate question
Good morning (or maybe noon, if you're east coast),
<It is now the afternoon here.>
I'm building a DIY refugium with a DSB. I've seen you recommend Home Depot Southdown sand before. I went to my local Home Depot and they did not have anything by that label, but they did have "playground sand." It was sugar-fine, composed of crushed marble, taken from calcite ore.
<You do not want calcite. It does not dissolve nearly as well as aragonite. There was a very good article in the October 2002 issue of Tropical Fish Hobbyist by James Fatherree discussing the differences.>
It was labeled as over 99% silicate free. Is this essentially the same thing as Southdown?
<It does not sound like it.>
Would this work for a DSB or should I consign myself to the high prices of my LFS?
<I would continue to search for a better product. There are several online vendors now selling Southdown like sand. I would also ask a local marine aquarium society. They could probably direct you to someone that sells Southdown or a similar product.>
Thanks for your counsel, John
<Good luck! -Steven Pro>

DSB substrate question
Good morning (or maybe noon, if you're east coast),
<Ahh Hi John, West Coast, a fine sunny morning!>
I'm building a DIY refugium with a DSB. I've seen you recommend Home Depot Southdown sand before. I went to my local Home Depot and they did not have anything by that label...but they did have "playground sand." It was sugar-fine, composed of crushed marble, taken from calcite ore. It was
labeled as over 99% silicate free. Is this essentially the same thing as Southdown? 
<Hmm, don't know if this is crushed marble or coral? There are several versions from Southdown of Caribbean aragonite sand. Some is labeled "Southdown Plays and" and some "Playwright play sand". You are looking for Caribbean aragonite, "mined" from the Caribbean. Also, look in the Garden Dept, not the concrete dept where they will send you for sand. If the bag is from Southdown (on the back label) you can confirm the contents by calling Southdown at (800) 526-1753.> 
Would this work for a DSB or should I consign myself to the high prices of my LFS? Thanks for your counsel, John
<Yes. It will work fine. You may also seed it with "live" sand from your LFS or LR. Go for it, we can't get it out here! Craig>

Substrate for big Australian tank and Seagrasses
Hi Anthony
<cheers, mate!>
I'd like your advice on suitable substrate/s for our 600,000L display tank, 
<glad to share an opinion>
remembering that the water depth will be six meters and the habitats we're to show are sand, coral, seagrass and rock. In Shark Bay there is a small bivalve (Fragum erugatum) which proliferates in the hypersaline areas to the extent where its empty shells are harvested and sold in large quantities. The processed shells are typically 8mm diameter, hard, white and I assume composed of calcium carbonate.
<yes... some form of calcite>
Recently the processors have been crushing this shell to a 1mm to 2mm grain size and selling it as an aquarium substrate. I was thinking of using the same crushed substrate in our tank for the "sand" and some of the "coral" sections. How thick should I make it here? 
<that depends on your intent and to some extent the livestock. If you have no other means of denitrification and will consider a deep sand bed methodology in the display proper, then we need 15-30 cm bare minimum. And in such a large display... I really must say that 30-60 cm would be quite nice. The advantage is that it will provide natural plankton (nanoplankton, bacteria etc) and naturally denitrify will little support. The disadvantage is that it could be a liability with inadequate water flow and become a nutrient sick and support dreadful nuisance algae. Nuisance algae could be further mitigated if the material is rich in silica, which as a mollusk it is quite possibly so. My advice is to get a assay of the materials composition and compare it to a known "safe" substrate commonly used by aquarists or public aquaria. That will tell us first if we can even continue to consider these crushed shell as a candidate>
Do you think this substrate would also suit the "seagrass" section, or would it need to be finer than this? 
<I must admit... I am somewhat concerned that this is a little too course for seagrasses and good denitrification (if the bed is shallow). Here in America, we commonly culture Thalassia and Syringodium (some Zostera too) in muddy fine substrates ranging from .2 to .5 mm>
I would like to grow local species of seagrass and notice that the natural substrate is a lot finer than this, and more silicon-based rather than CaCO3. 
<interesting about the silica. I'm not sure if it is utilized or simply tolerated by the grasses though. Still... if the course media is to work at all... I am sure the grasses will need to be planted rather deep... 8cm minimum.>
Would I be better off using the same substrate as found in the bay, or would this silicon-sand be likely to encourage diatom blooms? 
<indeed... I'm concerned about excess silica in a closed system where large water changes are not convenient if necessary>
Perhaps I could have some of the shell substrate crushed a bit finer if this is important for seagrass. 
<if possible that might be ideal. Do know too that the dry substrate will need to age for some months before it can support the seagrasses. When you collect the grasses, you will need to collect them like plugs (large cored berths) if you are to have any chance of successfully transplanting them. Perhaps you can just take a little extra natural substrate with you and seed the dry crushed shell in those few spots where grasses are planted early while we are waiting for the rest of the bed to mature and the grasses to spread> 
I notice many seagrass species have roots that penetrate at least 300mm into the sand. Should I make our substrate in the "seagrass" section this deep? 
<it does not have to be quite this deep in my opinion... but they do need deep beds and anoxic conditions. Hence the need for deeper substrates if you use courser media (the course media allows better/unwanted penetration of oxygen rich water)>
Is it possible to have the substrate too deep?
<not likely at all... if you said you wanted it 90cm deep, I would have no complaints!>
One other thing I have noticed is that the sand in the bay seems to be quite nutrient-rich - when you dig down 100mm or so it becomes a grey color rather than white and smells rather organic. Do seagrass species use nutrients in the soil for growth, or are the nutrients obtained from the water as for other marine plants? 
<they derive nutrients from roots, stems and leaves... but a rich substrate is quite important>
If the soil is a major source of nutrients, do I have to enrich my substrate before it will support seagrass?
<yes... recommended here as per above with this soil buried in little pockets where you first transplant seagrass plugs>
Our construction is still going forward, although rather slowly. 
<all in good time... like fine Australian wine :) Ahhh... if only I were sipping Shiraz/Sirah right now!>
At least six months until we can put water in it. Gives me plenty of time to learn all these important things :) I'll send more photos when the tank is at full height.
<excellent, my friend. I'm looking forward to it!>
Thanks again Pete McKenzie
<Pete, do look over these links for advise on transplanting seagrasses. Some very good information on harvesting and transplanting techniques.
http://chl.wes.army.mil/library/publications/chetn/pdf/cetn-v19.pdf
and here:
http://chl.wes.army.mil/library/publications/chetn/pdf/cetn-v11.pdf
With kind regards, Anthony>

DSB, etc.
Hello again:
<Greetings!>
So, I read info on your site about LS and DSB's until I was bleary-eyed (and still have not finished).
<I know that feeling as well!>
I then went out and bought some Southdown Tropical Play Sand that I saw mentioned. Then I realized after putting some in, that 4" is a whopping 20% of my 55gal tank depth. WOW!
<It is a trade off for everyone.>
I was surprised it was so DEEEEEP. I already suffer from tank envy, and the thought of losing that much height pains me.  I read on your site that someone had a 29gal, and your crew said that they probably would not need it so deep because of the lack of size.  Is there a more accurate sand-to-depth percentage to use as a general rule that may be better?
<Not that I am aware of...either very thin, like less than an inch Or deep with 3 inches on the shallow end of DSB and 4 inches + even better>
maybe a surface-area-to-depth?
<I've personally never heard of anything like that. DSB's are somewhat controversial, therefore opinions differ. Compare the DSB idea to the concept of a Berlin tank. They are the exact opposites yet many experts believe DSB's are the only way to go...just as many think they are just a nutrient sink. You must read/learn and decide for yourself. I had to make the same decision for my tank.>
I did not catch any info on that on your site (yet).  If AQ <AQ=Aquarium?> husbandry success is truly on a case by case basis (isn't it?),
<Quite frankly, people that are serious enough to read/learn about water management, disease, stocking, etc. and buy a few books will be successful in this hobby. It is the people that buy a tank, put in salt water, and start throwing in critters that leave this hobby with their wallets lighter and a chip on their shoulder. You are well on your way to being a success. Keeping learning.>
How would I know without trying lesser depths that it is working or not?  
<The differences will be subtle either way.>
Also, I read you can siphon out your old CC substrate instead of the messy way.
<Not if the CC is really big pieces. Small pieces the size of  freshwater gravel will siphon out easily. Just get a cheap gravel vacuum and hose from any good fish store. Buy the largest size you can find.> Is this by using gravity alone?
<Yes!>
What thickness of tubing would I need? 
<See above.>  
Thanks for your helping "the new guy".
<Don't worry my friend. All of us were new once! There a lots of differing opinions in this hobby. You need to read everything available and then decide what makes since for your aquarium. You're on the right track! Knowledge is power! David D.>

CC vs. LS
I recently had a 72 gallon reef-ready bowfront FO tank set up last week. I am cycling it with 9 damsels that have been in for about 6 days. Here are my questions:
I currently have a substrate consisting of crushed coral. I have heard several people say that sand is a
better substrate. Is this true? 
<It all depends on what purpose you hope the substrate will serve. If you want the substrate to look good and help buffer the water, crushed coral will be fine.  I would caution against having a deep bed of CC because it will become a nutrient sink in short order. Use a thin layer only. In a reef tank, sugar sized sand will slowly release natural calcium, help to buffer the PH, and if the bed is 4 inches+, it will aid in nitrate reduction.> 
Is it better than CC? 
<IMO not for your situation.  For a reef tank?  Yes.> 
Also, I have heard people say that you don't have to vacuum sand. Is this true? 
<We don't vacuum sand the same way we vacuum CC, that's for sure! The sand will quite literally vacuum right out of the tank. But you will need to very gently vacuum the surface of any obvious debris when cleaning the tank. If using sand be sure to either have a thin bed (one inch or less) or a thick bed (4+inches) of sugar fine sand. Otherwise you will create a nutrient sink> 
If I decide to change the substrate, should I wait until the tank has cycled? 
<Either way you're going to interrupt the biological process happening in the tank if you remove all the substrate at one time. I suggest taking a little out at a time over a period of a few weeks.  Slowly add the new substrate as the old is being removed.> 
What is the best procedure for doing this? 
<See above>
Thanks for our help. Jerome
<My pleasure Jerome.  If you haven't perused the wetwebmedia.com website, please do so.  The site contains thousands of articles and facts and issues relevant to the keeping of saltwater and freshwater fish. Have a nice evening! David D.>

Live sand question
Hi James the salty dog or whoever reads this, 
<Hi Shawn>
I looked over the link and asked my local fish places about it and have decided to just go with sand only. I have one last question regarding the live sand. I remember reading one response, I could've sworn it was on page one of the live sand questions and I've re-read both FAQs twice now but I can't seem to find it again. I thought I read on one of the responses that it is ok to buy play sand from home depot to use in your aquarium and to seed it with some live sand or live rock. Is this still ok or has it been found not be safe now or anything.
<I would not use it because of the high amount of silica present, additional algae food source, and it will do nothing to help keep your pH up.> 
Sorry one more question, the live rock I'll be getting for my tank is most likely going to be uncured and since I'll have an empty tank and I plan to cure it in the tank would it be ok to just add the sand while it's curing or should I wait till it's done curing and then add the sand? 
<Problem with that is with all the die- off from the rock, it will be harder to vac the crud up with the sand being in there. James (Salty Dog)><<RMF would like to throw in a point here... HD sells both a near-pure silicate "Play Sand"  and a "Southdown" product that is almost entirely carbonaceous... there is very little silicate content in the Home Depot Southdown product... this last should work fine.>>

Sea Sand Bed - South Africa 3/30/05
Hi guys & girls fantastic site!! I have a question: in about a month's time I am going on holiday to our eastern coast of South Africa (Durban). I currently have a 400litre tank with a medium depth sand bed consisting of crushed coral and aragonite. I was wondering if I can bring back some sea sand back from the coast to give my live sand a boost. The sand by our coast consists mostly of just plain sea sand and crushed shells. Can I use this, isn't it too fine in size ? What do you recommend? Thanking you in advance. Werner Schoeman 
<There are many caveats to this. Temperate animals will not survive long in your tropical tank. Also, temperate sands may not be coralline in origin, so they won't add to buffering capacity and may contain undesirable elements. Pollution is also a concern. "Live sand" is (or should be) collected off shore in tropical regions near reefs. Best Regards. AdamC.>

Just How Small Is This Place!? II - 04/28/05
Thanks Eric. 
< Most welcome. >
Also, I recently got rid of my sand substrate because it just seemed to give me problems with making parasites linger in my tank. I want to get a fine gravel type substrate. Would dolomite and crushed coral be comparable? Do they have similar benefits or is one better than the other? 
< Crushed coral is the better choice, aragonite even better. >
Couldn't find anything about dolomite in the FAQ'S.
< I assure you this subject is well covered...a simple Google search on the words "dolomite", "crushed coral", or even "marine substrate" will yield many hits. >
Thanks again.
< Regards, Eric R. >

Marine sand source
Hello to all,
My quest for sand continues.  As the company that produces Southdown sand is no longer in business and the only place in the United States that still has some is in the central states I have found another possible source for sand and would like your help. :)  There is a company in Monterey that dredges up sand from the bay.  They sift it and kiln dry it and package it for sale.   The lady I spoke with today says it passes a through a 20 ?? sieve. 
<A physical sizing... twenty average grains lined up end to end would equal an inch... about this size will fall through openings in such a strainer>
Is this something that would work in a reef tank??
Thank you,
David
<Mmm, likely not... probably is largely silicate based... Please read here re: http://www.wetwebmedia.com/marsubstr.htm and on to where you lead yourself through the linked files at top. Bob Fenner>

A Million Grains Of Sand...Free For The Taking?
Hello,
<Hi there! Scott F. here today!>
We are heading to Jacksonville, Florida for a week this summer.  We are staying at a family friend's house on the beach.  Is it possible to use the beach sand in our aquarium? Brian
<Well, Brian, this is a pretty common thought for us crazy hobbyists...I mean- why not? It's right there...it's free, it's...well- actually- it's probably a really bad idea! Besides the fact that beach sand is a fairly precious natural resource (in my area, the sand at local beaches helps prevent erosion, and this is really important!), sand collected near or on shore could contain all sorts of potential pollutants, ranging from simple organic silts to possibly toxic chemicals or agricultural runoff. Most of the packaged sand that we buy at the LFS is not beach collected, so it is generally free of these potential pollutants. Personally, I'd resist the temptation and fork out the bucks for pre-packaged sand. Enjoy your vacation! Regards, Scott F.>

Sand
Hello and thank you for all you do :) <You're welcome>
I have been reading about Southdown sand and what I have found is this.  
Their supplier went out of business so they don't have the tropical play sand anymore.  I tried Quikrete and Basalite and their products are not aragonite.  Do you have any idea if there is anyone selling sand at decent prices.  I just spent $200 putting sand in my 100 gal refugium and now have to sand my 150 gallon tank. <David, I've been hearing the sand Home Depot sells is Southdown sand.  I'm sure Mr. Fenner will see this and maybe he can confirm. James (Salty Dog)>
Help,
David

Mystery Sand...
Dear Crew,
<Scott F. your Crew member tonight!>
I know this topic has been covered extensively on your site and throughout the net. BUT... A fellow aquarist and I just ran into a pallet of "Yardright White Play Sand" at a local store. We've been HUNTING for Southdown substitutes all around but of course we cant find it. The bag says that it its made from marble, and we brought our "Vinegar" test kit with us and it bubbles.. so we bought some.... We both want DSBs in our new tanks. I've seen Aragamax, and its not near as white as this stuff.  Is this the right stuff?????
THANKS!
<Hmm...since this stuff is not aragonite based, I wonder about its buffering capabilities and level of purity, despite its apparent solubility. I'd be more inclined to pass on it for this very reason. Do check with other hobbyists to see if they have used this stuff with success, but proceed with caution. Good luck! Regards, Scott F.>

- DSB, Sand Selection, and DIY LR Questions -
Hello, WWM Member!
It's so nice to have such a great resource to help those of us without a lot of hobby experience.  I'm still in the planning stages for a 70-90g peaceful reef tank, and I'm confused on certain points.  I have done TONS of reading on WWM regarding these questions, and I haven't found consistent answers... perhaps some of my questions have no conclusive answers!
First, regarding DSBs.  I know that optimally, 6"+ is best.  Is 6" optimal? <Six inches is the minimum, not optimal. Eight to ten inches would probably be optimal, if not always practical.> If not, what's the optimal depth?  (I know that making it too deep can cause hydrogen sulfide problems; at what depth do problems develop?) <Not sure this is empirical. I have a 12" DSB sump that's been running for a year and have had no problems with hydrogen sulphide. Think sulphide problem may result from sub-optimal depths, where the proper bacteria that would make use of this stuff do not exist.>
I've done a lot of reading regarding substrates, and I'm confused.  I've read that Jawfish and other burrowers are best kept in fine sand with some coarse material to aid their burrowing, and that these fish move around the bigger pieces to their liking; I've also read that coarser material mixed in won't harm anyone.  However, I've also frequently read that you shouldn't mix substrate sizes so channeling/packing is minimized. <I mix substrate sizes all the time - especially in the fish tank - seems to allow for better fauna development in the substrate.> So, the question: if I'm keeping Jawfishes, gobies, and the like, what should I do?  Should I stick with pure sugar-fine aragonite sand, or add some crushed coral, or add even coarser material like crushed shell? <I'd do all three.> If I should have coarse material, what ratio is best? <Perhaps 1/3 of each.> I just want to make sure they have the best substrate possible.
Also, I'd like to make some GARF Aragocrete "Reef Tables" and a couple caves for my tank (I'll have plenty of "real" live rock, of course).  I've heard some people have no problems, and others make claims that the cement adversely affects tank chemistry.  What's the truth? <The truth is that anything cementacious would need to be cured for a while - months - in a weak acid solution (vinegar would do) to help bring down the highly alkaline nature of cement products.> Would I be foolish to use Aragocrete, or will I be fine? <No... this has been done for decades in public aquariums and the like - is perfectly viable as long as you take the appropriate precautions.>
Oh, one last thing, if I may.  I plan on principally keeping quiet fishes, like gobies, Banggai Cardinals, blennies, and perhaps a Jawfish or eventually a mandarin (with a refugium, of course).  But... I (and my wife) would love to have a yellow tang (Zebrasoma flavescens).  Would it be too boisterous or aggressive a feeder to mix in this type of tank? <Would be fine.> I'm worried that the other fish wouldn't get enough food... Also, is there any species of clownfish that could coexist peacefully, as well, or are they too aggressive? <My favorite are the true and false percula clowns - they seems to be the most docile of all the clowns and seem to get along with just about anyone that won't eat them.>
Thanks so much for your time and help; I truly appreciate your advice.
Scott
<Cheers, J -- >

Marine substrate
Hello All
I want to first say thank you for all the great info on this site.  :)  Done much research into my nitrate problem and have formulated a solution due to all the great help already posted.  Only could not find one last answer.  
For my deep sand bed is it ok to use sand from an home improvement store?  
<Yes... if carbonate based... steer away from silicates. Please read here: http://www.wetwebmedia.com/marsubstr.htm
and on to the links at the top, till you're satisfied>
Oh yeah one last one... My current substrate is of the big variety, yes I know one of the reasons for my nitrates anyway when I create my DSB can I pour the new sand over the existing substrate?  Thanks again for all your help, this site rocks
Cheers
Fargo
<Keep reading the links... Bob Fenner>

Live Sand? - 06/20/05
Thanks for that.  When you say sugar-fine sand bed you are not referring to live sand?
<<Nope.  You can use any sugar-fine sand...even silica sand (I can hear you gasp <G>.)...though I confess I prefer to use aragonite when available.  Just seed the "dry" sand with a bit of sand from your mates tanks or from the LFS and it will become "live" in short order.>>
Also I should put some critters in the refugium as well correct?
<<Depends on what you mean by "critters."  If you mean amphipods, Mysis shrimp, copepods, bristle worms, and the like...then the answer is yes...if you mean shrimp, crabs, small fish, etc. ...then the answer is no.  The latter defeats the purpose of the refugium.>>
Thanks for the info you guys rock.
<<From this old rocker...Regards, Eric R.>>

Local sand
I was wondering if sand from a local freshwater sandpit could be used for substrate. I would seed with some live sand. It is in a 1000gal tidal pool/fuge I am constructing. Time is not an issue and I can wait for it to become live sand. Also wanting to use some local stones as rock, porous limestone type. plan to seed the rock with pods etc. will this work. it would cost a small fortune to buy from LFS or online pre- cured, etc.
<If these materials are indeed calcium carbonate based you'll be fine. I would ask the folks who run the sandpit the composition of the material there... if it is more than a few percent silicate based, you would be better off seeking out another source... for reasons stated here: http://www.wetwebmedia.com/marsubstr.htm Bob Fenner>

The best sand bed situation?
I've been reading your site for days. I cannot find a definite answer on sand beds.
<Welcome to the club. Sand beds have to be one of the most debated facets of the marine aquarium community. Everybody has their own opinions and methods, so there really is no "definitive" method of keeping a sand bed.>
I have a new 125 gallon all saltwater fish tank. I have 50 pounds of Aruba crushed shells (Puka shells). is this the best way to layer the bottom of my tank.
<As they say, there is more than one way to skin a cat. Out of the many ways to go with a sand bed, not any one method is decidedly better, or decidedly worse than the next. You should check out the following wealth of informative links and make an educated decision as to what course to take.
http://www.wetwebmedia.com/marsubfaqs.htm 
http://www.wetwebmedia.com/marsubfaq2.htm
http://www.wetwebmedia.com/marsubfaq3.htm 
http://www.wetwebmedia.com/marsubfaq4.htm 
http://www.wetwebmedia.com/marsubfaq5.htm 
http://www.wetwebmedia.com/marsubfaq6.htm 
http://www.wetwebmedia.com/marsubfaq7.htm 
http://www.wetwebmedia.com/deepsandbeds.htm 
http://www.wetwebmedia.com/marsubstr.htm >
Do I go an 1" or 4"? Can I, should I mix it with a sand base? Overall what is the depth you suggest I should lay down?
<Once again, it is a matter of what you think will work best in your situation.>
Thank you so much for your time and response.
<Glad I could be of assistance. Good luck, Mike G>
Thomas Duffy

Home Depot Sand Response
Previously posted:
I thought I read on one of the responses that it is ok to buy play sand from Home Depot to use in your aquarium and to seed it with some live sand or live rock. Is this still ok or has it been found not be safe now or anything?
<I would not use it because of the high amount of silica present, additional algae food source, and it will do nothing to help keep your pH up.>
*****************
I would like to respectfully disagree with this response. The Home Depot sand that is referred to here, [which] used to be the 'SouthDown" brand, is not silica based sand. It will indeed help with keeping your pH stable. It dissolves in vinegar, silica- based sand will not do this. I used around 300 pounds of it for my tank and it has been doing wonderful for nearly 2 years now. I believe the Southdown name changed to Yardright, but I'm not sure.  You can always test it by dumping some vinegar on it. 
<Thanks, Bill, but you did not mention Southdown sand, and if you were using it for nearly two years, and doing wonderful, why are you asking about it? Seems to me you've done your own homework. James (Salty Dog)><James... this gentleman was chiming in on your previous day's post... FWIW, I do agree with him... the Southdown product is almost entirely carbonaceous, very little silicate content... RMF>>

Southdown Sand
James,
I'm sorry, I wasn't clear. It wasn't my question originally. I just read it on the FAQ's yesterday and thought I'd pipe in, and share my experience with this fellow and other readers. Home Depot is the only place that carried the Southdown brand that I'm aware of. So when I read Home Depot sand, I assumed he was talking about Southdown. Sorry for the confusion. 
<Bill, yes it was confusing. Apology accepted. James (Salty Dog)> <<Sheesh. RMF>>

Sand bed
Hello All:
<Scott>
I am considering changing my sand bed from a plenum to a sugar grain DSB. I would like to just add the sugar grain size sand to the existing bed but I am worried about an anoxic situation that will produce sulfur dioxide? 
<Maybe... but not if the system is otherwise managed properly>
I am worried about a nutrient sink with the grain size specific to a plenum. Maybe I should leave well enough alone!
Thanks
Scott
<Maybe. Plenty on plenums, substrates archived on our site: http://www.wetwebmedia.com/ Bob Fenner> 

Substrate Selection
Hi WetWeb crew,
I looked over your other answers about live sand and well my question is pretty stupid and basic compared to everyone else's but I'm really new at this. Anyhow I am starting with a 50 gallon tank (48x12), aquatic ProClear pro wet/dry filter, and I'm trying to decide the best substrate to start with. I plan on getting live rock, but with the live sand I'm not really sure what is best. I like the look of the crushed coral aragonite stuff, but my bf who just recently got into marine aquatics 7 months ago told me that the crushed coral might not be compatible with some life forms? 
Like if I want to get star fish or gobies or other types of sand sifters. I have looked but I haven't seen anything that says sand particle size affects which critters you can get, except for an ad for this really fine particle sand saying it was more gentle on gobies' gills. Would it be ok to get the crushed coral and still be able to get sand sifters or would the large size of the substrate harm them when they try to sift through it? I also read that the crushed coral is better than regular sand because it buffers your system more, so would that be the best to use or do you guys feel that regular small grain sand is better? 
Sorry for being so long winded in my question and thanks a bunch!!
<Shawn, I suggest you read through this link. It will inform you better on your choice of substrate, more so than I can do here. http://www.wetwebmedia.com/marsubstr.htm. James (Salty Dog)> 

Alternative sand substrate
Hi Mr. Fenner,
I've been reading in your daily FAQs, and older FAQs from lots of people that use the Southdown play sand from Home Depot.
<Yes, a dear acquaintance is quite "buff" (she) from hefting several pallets about this far to the west (California)>
Unfortunately, I live in Montreal, Canada, and we do not have that brand here. Although we do have the Home Depot store chain here.
<Do make inquiries... if you can get a few pet-fish friends together, perhaps a whole pallet or two can be special ordered, shipped up>
They do carry the line of different types of sand of another brand that is called Quikrete. I've looked at the sands, and while they do have what they call a common blend of sand that has a warning on the label that says it contains silica in it, 
<It does, in high concentration>
they have another blend that is labeled for sand-boxes that has been washed, cleaned, and dried, and does not say anything on the label about any silicates in it. Have you ever heard of this brand because the company is in the States? 
<This natural product is not consistent... you can look with a magnifying glass, low powered microscope to easily assess how much silicate/sand is present... the shinier, flatter, smoother "poker-chip" like pieces...>
Would the fact that nothing is on the label for the play box type about silicates make it safe enough to use in a reef-tank, or it means nothing, and I would be better off not chancing it? 
<Worth investigating further. Please do post your query to our: http://talk.wetwebfotos.com/ and other bulletin board, chatforums in the hobby... some folks will certainly have recent personal experience here>
I figured that if this sand is catered to sand-boxes, they would know enough not to make it health hazardous for the children that will be playing in it, since the silica is a known cancerous agent.
<Umm, actually... most everything is a "cancerous agent" (in point of fact our bodies are quite cancerous... not a joke)... in quantity, type of exposure... In the grand scheme, scale of things, large particles of silicon dioxide (a very common, ubiquitous component of the surface of this planet) are relatively non-toxic>
I would really like to find an alternative to buying something like the CaribSea brand because around here, the cheapest I've found for CaribSea is $32.00 for 15lbs., while the Quikrete brand for instance costs $4.95 for 50lbs. What a difference in price eh!!!!
<I'll say! See my comments above...>
I've also looked online at the CaribSea brand, and while it is cheaper a bit, once you add in shipping etc. it comes out to the same price. I just think it is crazy to pay that high price for sand, ( while the composition of the CaribSea brand might justify the high price, I would really prefer an alternative if it would do just as well, as this hobby is expensive enough!!).
<Agreed... but not for the industrious! Bob Fenner>
Thanks in advance,
Greg N.

Is Pink Fiji Sand O.k. stuff?
Bob,
Thanks for the help lately. Much appreciated.
<You're welcome>
Is there any reason not to use Pink Fiji Sand in my main tank? I plan to have stars and maybe a sand sifting blenny. I forgot who it's packaged by, the packager is something like Custom Imports (they package aragonite sand also). Anyways, it's made for marine tanks, but wanted to make sure there wasn't any reason not to use it. 
<None I'm aware of>
I already have a sump with a plenum using aragonite sand to help with buffering, but wanted something a little more fine and appealing in the main tank. I assume you have to keep an eye out not to get this stuff too deep, in case of it going anaerobic. Do you recommend a max or min depth?
<Not really... but to do as you suggest... keep it stirred, an eye on it...>
Thanks again. Got your book (CMA) last week, love it...
<Ah, good to hear/read. Be chatting. Bob Fenner>
Dan

Moving Substrate to sump, and what kind of Carib-Sea to get?
Bob,
Thanks for your help recently.
<You're welcome>
I'm adding a 20 gallon or so sump to my 38 gallon FOWLR. It will have a plenum and macro-algae. I currently have Carib-sea Geomarine crushed coral in my main tank, about 1" deep. I want to change to sand in the main tank.
<Good idea>
Three things:
I want to use the crushed coral from the main tank as the bottom layer in the new plenum for the sump. Is this the right size crushed coral for the bottom layer, and is it o.k. to use the current crushed coral? Or is there a better bottom layer material.
<Should be okay... use a plastic screen mesh (like material available for screen door replacement) on top of this layer and finer material (likely coral sand) on top...>
I want to change to sand in the display tank. I'm hoping you are familiar with the different Carib-sea kinds of sand.
<Yes>
What is the best choice for the main tank. It won't be a deep sand bed. The choices are Carib-sea pure Caribbean Aragonite(0.18-1.2mm), Carib-sea Aragamax(0.5-1.02mm), or Carib-sea Special Grade(1-1.7mm) I would like to have a blenny or starfish in the main tank.
<Myself... would go with the last (Special Grade)>
Of the three Carib-Sea choices above, what is the best choice for the top layer of the plenum?
<As stated>
Thanks a million, you're an excellent resource, and your book should be arriving on my doorstep today courtesy of UPS.
Dan
<Be chatting, and taking up your time... pleasurably, my friend. Bob Fenner>

Mixing sand grains
Hi Guys,
<Harrow>
Quick question please! I have a med sized sand (CaribSea Aragonite)
<ech...>
and bought additional sugar sized 
<woo-hoo>
Is it okay to place the sugar sized over the med-size? 
<not recommended if your goal is denitrification (all fine for that). If not, please at least add screen between layers with course grain on the bottom>
My plan is DSB about 6" deep. 
<excellent!>
Thank you guys you're doing a mighty fine job of educating us.
<thank you for saying so, good sir. Anthony>

Substrate
Anthony, thanks for quick response on last question.
<my pleasure, good sir>
Some questions about substrates.  I currently have Seaflor Aruba Puka in my 75 gallon fish only.
<beautiful but not at all functional without serious water movement and activity on the substrate...speaking from experience>
I was looking at switching to CaribSea special grade, but not sure if that is the best choice, would like some input.
<equal size grain of whichever you choose... closer to sugar fine (oolitic) is better for denitrification. whereas coarse encourages more natural amphipods and the like>
I'm planning on taking a third of the old out at a time. How long in between taking another portion of substrate out?
<no hard and fast rule on this one... monitor nitrogenous elements to be sure. Intervals of weeks and not days for perspective>
I was the one with the Koran and Naso and you recommended leaving my biomedia in my CPR wet/duty along with adding live rock.
<yes... as a hardcore reefer (rock only) it took a lot for me to admit it...hehe. But the bio-load will be significant when these fish mature>
Question is....I've seen that Seachem has a product which is a biomedia called matrix to replace the BioBale/bioballs.
<I have no love for bio-bale...but I am quite content with bio-balls>
It is suppose to complete the nitrogen process by turning nitrates to nitrogenous gas, is this stuff good/bad your input.
<no experience with it, but dubious under a good bio-load such as yours>
Reason I'm asking and no surprise to you, I've been getting an increase in nitrates, even with regular water changes (B/C of wet/dry). thanks Bryan.
<indeed... the more efficient the bio-filter is as the fish grow, the worse the nitrates will get...almost ironic. You can look into various denitrification filters... some DIY (coil, Deep Sand Bed, batch, etc) but water changes will always be a best bet. Consider automating the water changes. Inquire if you go this route for assistance. Best of luck to you, Anthony>

Silicate based sand
Robert,
I'm looking into silicate based sands for my marine FOWLR tank. The only reason is that I can fill my 80 gallon long with 3 to 4 inches of sand for
$5 versus the $200 for any of the local aragonite sand. Some people say this is fine. Others say it isn't.
I realize that with silicate based sands I'd get no PH buffer and I could have a problem with nuisance algae. Then again, I've also read that the algae won't be any more of a problem than with aragonite sand. I can seed the sand with GARF grunge (I live about 5 miles from GARF so that's not an issue at all) but I'm curious to know if there is any reason silicate sand wouldn't make a good live sand bed.
Any thoughts? I'll probably get the aragonite anyway, but I'm just really curious.
<Please read here: http://www.wetwebmedia.com/marsubstr.htm 
I would not use a silicate based substrate in nearly all types of marine set-ups... for the reasons you have listed above and others in the article cited. Bob Fenner>
David Rencher

Re: Silicate based sand
Oh, you mean I could have just read the website for the answer? DOH! How silly of me to forget. Thanks
<Thank you my friend. Be chatting. Bob F>

Sand 
I just need a small amount of sand for the bottom of a 20gl tank. My LFS only has bags of it in 30lb. increments and it's very expensive. Is it ok to just get some sand off the beach or within the first few feet of the shoreline and really rinse it thoroughly or would it be polluted and unusable? Thank you.
<Please read here: http://www.wetwebmedia.com/livesand.htm and the associated, linked FAQs. There are other companies that will sell, send you smaller amounts including just a few pounds of "safe" LS to seed your system. These are linked on our sites. Bob Fenner>
Elizabeth K. Birdwell

Substrate Questions
Hi again, and thanks for the excellent advise as usual!
I have another question about the type of substrate to use for my new 180 gallon fish only tank. I prefer to use a very thin layer of sand grade for the substrate instead of a course coral substrate based mostly on what I was reading in the WWM FAQ's. I noticed someone stated course substrate is harder to maintain, more detritus and "bugs" can develop in the substrate. Is this true?
<All three are true, the first two are disadvantages, the last part about bugs is a good thing.>
I was told be someone else not to use sand for a fish only tank, not sure exactly why.
<Bare bottom tanks are very easy to clean, but can be ugly.>
I have a good protein skimmer, (DAS BX-1) and it appears to be working fine now on my smaller tank in keeping the nitrates down, (around 15-20p) . My intent is to keep the nitrates really low and eliminate much of the extra debris / detritus that develops on the bottom of the tank. If sand is ok, how deep should the bed be?
<For good denitrification and no settled detritus, use a 4" sand bed of fine sugar size aragonite.>
Any suggestions would be great!
<Have a nice night. -Steven Pro>

Sand Preference
I'm working on going to a deep sand bed. Quick question. If I go to 4" or so for the deep sand bed, is it better to use Carib-sea Seaflor (about 1mm) particle size, or the oolitic Aragamax (0.3-1mm)?
<I have some of the Carib-Sea Special Reef Grade stuff and do not like it. I much prefer their Aragamax product.>
Will the smaller grain size be too easy to disturb with high current flow flowing through the tank (12x).
<Not unless directed down at the sand. I have never had a problem with it and many of the tanks I setup have flow rates approaching 20X per hour.>
This is for a fish w/ LR system. Just not sure what the better substrate is. I would figure the Seaflor product since its been out longer and I've used it in the past. Not sure if the sand would be just too fine. Any insight would be appreciated. -Jim
<The larger grain size tends to allow detritus to settle between the sand particles and requires regular vacuuming to keep clean. Also, I had have a terrible time getting anything to grow in it. I have inoculated it many times with various worms, many starfish, and pods and they do not do well. -Steven Pro>

Substrate Follow-up
With all due respect Steve, I just want to question your advise on using the 4" substrate of aragonite in my particular setup. This is going to be a large fish only tank. I do not plan on keeping any small invertebrates or fishes used for stirring up the surface of the substrate, (in order to create the denitrifying aerobic bacteria).
<You don't really need any small fish to stir your sand. Most of this can be effectively accomplished by the tiny critters that make the DSB their home; bristleworms, Chitons, amphipods, copepods, spaghetti worms, etc. I merely mentioned the DSB possibility because you referred to eliminating nitrates in your question about substrate options. I thought that was where you were going.>
Shouldn't I just use a very thin layer of aragonite to avoid any problems?
<A thin layer will be fine. -Steven Pro>

The Opinion of Aquatic Experts
Hello WWM Crew, I have a couple of questions. Is it true that you should not have a big bed of aragonite? I have 270 lbs of Aragonite in my 180 gallon tank and have been told by 2 different people that I should remove it and replace it with crushed coral since the Aragonite will turn into a mush and retain all sorts of nasty things.
<Definitely not what I would do. I prefer to use a deep sand bed, 4" or more of fine aragonite sand.>
The other thing they said is that I should not run the skimmer 24 X 7 that I should only run it a couple times a week or that otherwise the LR won't get the nutrients that it needs, this was told to me by two supposedly "Aquatic Experts". Is this true or are they just out of their minds?
<I strongly disagree on both counts. Do not just blindly follow my opinion or recommendations. Get the advise of others. Read books, magazines, and online chat forums to formulate your own educated opinion.>
Once again thanks.
<You are welcome. -Steven Pro>

Silica in my puffer tank
Hi ..I have a new Tank (4 weeks after maturing) and I have 3 puffers in there...before I knew any different I used tap water and that has resulted in horrible brown water ..I have since moved on to RO water .. although reassures it will not hurt my cherished puffers I wondered if there was anything we can do top speed up the process of getting rid of the silica ..we have a poly filter and have put carbon into the filter .. thanks a lot Steve
<Mmm, there are a few things... some chemical filtrants, using other organisms to take up the silicate... but I would just wait... time and regular maintenance will resolve/solve this issue best. Bob Fenner>

Substrate question
Fond greetings to all of you at WWM
<and kind regards to you my friend>
Sincerely hope everyone had a great holiday with good food, good drink and most of all family and friends. 
<and you as well <smile>. In fact, we haven't stopped... Steve and I out to sunny California to visit our good friend Bob. A great feast and fellowship planned for tonight>
Anthony, thank you for your very prompt reply several days ago regarding my question on a used protein skimmer. I've decided to opt for an AquaC EV 180, rated for tanks up to 150 gallons.
<outstanding... you will not be disappointed>
Now, I have a question about substrates. I did a search on the WWM site looking for the answer but couldn't find exactly what I wanted. In one of the articles about setting up a marine reef tank, Mr. Fenner wrote, "Calcite with magnesium impurities. Coral sand, crushed oyster and coral rock. These are the most suitable media and buffers.
Size (2-5mm), shape (spherical), grading (all the same), and circulation (2+ gsfm, the more the merrier) have been gone over under properties."
My question: Is Mr. Fenner saying one can use coral sand OR crushed oyster and coral rock OR a combination of all three. Could I mix up all 3 types to use as a substrate? 
<not recommended... each/some have advantages over others. All are calcium carbonate... some calcite (crushed coral, shell)...some aragonite (best IMO for buffering)>
Actually, if you can, I'd appreciate you telling me if there is a particular brand name 
<no brand recommendation... all aragonite in the country is collected by one company and repackaged. Just buy the cheapest. Fine aragonite sand from Home Depot (South Down brand) is quite popular>
that you recommend that I can tell my LFS person to get in case he doesn't already have it on hand. I looked around on the internet, but a lot of places don't tell you the properties of the substrates they sell. I did look at Custom Aquatic, Kent Marine (their Biosediment looks like it might fit the bill), Eco System's Miracle Mud,
<I'm not impressed with the latter two regarding value for price paid. You literally need to be paying mere tens of cents per pound>
and Kordon Aquarium. Problem is, I just don't know which one to choose. The tank I'm setting up will be a 140 gallon with no UG filter (unless that's necessary); the AquaC skimmer, Tidepool 2, a Mag Drive 7 and Mag Drive 5 and JBJ lights. I plan on adding 75 to 100 lbs. of live rock or more if needed and, after 4 to 6 weeks (if all goes well), I'll begin adding some live corals (but no SPS corals or clams as you cautioned against that due to the lighting). 
<and do be sure to hold off on putting any coral or livestock in until most all live rock is in. Any added later must be cured at home (never trust any shipped rock to be cured)>
Then I'll introduce (after dipping/QT) 1 to 2 fish a month, some scavengers, cleaners, etc. Many thanks for the awesome site and the equally awesome advice! Diane (down in the Louisiana bayous and still eagerly waiting for delivery of the CMA book)
<best regards, Anthony>