Cement Background  11/05/08 Hello all! <<Hiya Jay!>> Quick question about cement backgrounds. <<Okey-dokey>> I made a background from Great Stuff foam, dead rock, and type II Portland cement. <<Okay so far ?though you could have omitted the cement and just gone with rock/coral bits and the Polyurethane foam>> It looks really great, but the gray color is boring. <<Will change, with time in the system>> Is there a pigment that I could add to the cement that is safe for marine fish? <<There are pigments that are meant to be used with cement that are suitable. Most home centers (Lowe's/Home Depot/etc.) will carry these, though you will likely be limited to terra cotta, black, or tan. These are usually a dry powder that is meant to be added to the wet cement at time of mixing. There are also liquid pigments available that *might* work to dye a finished/cured piece ?but I don't know how well this would hold up under water>> I was too nervous about using a pigment before, but the background has been up and running for 3 months now with no ill-effects to the fish. <<The biggest danger with cement products is the very high pH of the initial mix. But "curing" in freshwater will leach out the pH elevating compounds and render the product relatively safe>> Thanks, Jay <<Hope this helps. EricR>>
Re: Cement Background  11/05/08 Eric- <<Jay>> Thanks for the quick response! <<Quite welcome>> I did cure the background in freshwater for 2 months and then saltwater for 1 more, so the pH is stable. <<Excellent>> What I would like to do now is attach some replica corals (Natures Image or another quality brand) to the ledges for color and hiding spaces. I thought that I might use an epoxy (any suggestions?) <<An aquarium safe epoxy putty should suffice. You can buy from your LFS/etailer ?or pick up some RectorSeal epoxy putty in the plumbing section of Lowe's/Home Depot/etc.>> to attach the "corals" and then cover the epoxy (once it dries) with a thin layer of colored cement to make it look more natural. <<The epoxy will attract Coralline and other settlers rather quickly, really. And adding a fresh and wet cement mix to your system, even in small quantities, may cause pH/other issues. Do be aware?>> I did buy the dry mix tan and black color additives from Home Depot, (though I never used them because I could not find any info on their use in marine aquaria). <<As far as I know these oxides are not harmful to aquatic life. Although, I have only ever used them before in freshwater settings. But like the cement itself, I would think them to be safe after �curing� to leach any possible toxic compounds>> Thanks! -Jay <<Happy to share. EricR>>

Marine Aquascaping…Building Large Rock Structures – 03/01/08 Are there any products or substances such as mortars, plasters, or plastics that can be used in marine aquariums to fuse together pieces of dead or live rock and build large rock structures? <<There are…though for building a structure from “live” rock you will be pretty much limited to “mechanical” fasteners of some type (e.g. – Acrylic rods inserted through holes drilled in the rock) as using something like a hydraulic cement; though it could be applied “submerged”, will raise the pH of the water too high (about 12.0) and destroy the life in/on the rock>> I am looking to build a rock structure to hide a series of standpipes and returns in the center of a tank that will be 48" tall. <<Will require some thought/planning…but can be done>> I am worried that just gluing together the pieces will not be stable enough at this height. <<Indeed… Best to use some type of “skeleton” or frame upon which to attach the rock…and easily crafted from PVC pipe and fittings>> I have heard that products like Thorite are better than "standard" cement for this type of application. <<About any good “concrete” mix used with a plasticizer admix should work, I would think. But going this route, the end product is going to be VERY heavy>> I have also heard that there are water-proof plaster products that can be used however my goal is to use products that do not require long term curing due to leaching. <<I don’t know that a “plaster” would have the “strength” needed…as that provided by a concrete (aggregate) product>> Any suggestions are appreciated. -Adam <<I think for both performance and to lessen weight, a foaming Polyurethane adhesive may work best for you. The Polyurethane foam will not only form a chemical (glue) bond, but will “expand” in to the irregularities of the rock creating a mechanical bond as well. The Polyurethane is amazingly “sticky,” and is inert, as well as surprisingly strong, once cured (about 24hrs). You can get it in “black” from aquatic (pond) sources, or use the slightly less expensive GREAT STUFF insulating foam found at most any home center/hardware store. I suggest you build the structure in segments outside the tank and then assemble/glue the structures together with more foam in the display. Don’t forget to use a PVC framework to support the rock and foam…and do be especially cautious if using the foam in/around an acrylic tank as it may disfigure/etch the acrylic on contact. I used this material to build some large rock structures on PVC frames for my 375g reef some four years ago, and the foam/structures have held up very well. Regards, EricR>>

Reef Aquascaping…Do I need All That Rock? – 02/20/08 Hi, <<Hello>> I have a 75g tank. It has about 75-80 pounds of rock. 30 pounds of it are 3 gorgeous 10 pound Marshall show pieces. <<Nice…though maybe a bit large for this size tank (matter of opinion)>> I am sure you know how costly that was, well at least to me. <<Indeed>> A friend keeps pushing that I need to buy a lot more rock, and it must be purchased at one time, before I can hire his service to redecorate. <<…?! Hmm, I wouldn’t be too quick to do this…I think we hobbyists often add “too much” rock to our systems; only to discover effective water flow throughout the tank is difficult to achieve , corals have no room to grow, fish have no room to swim/exhibit normal behavior , etc. The rock you have now will likely handle your bio-filtration needs just fine…and if you have a substrate, this too will provide much benefit/support re. Much better to not overfill the system with rock, in my opinion>> Why? <<Perhaps misguided advice…perhaps trying to make a sale…don’t know really>> I am disabled and the rock I bought previously, I bought a little at a time at another store. I need the reasoning behind this statement. <<If the rock is not cured, buying and curing all at once (outside the system) reduces the repeated hassle…but there is no reason you can’t also do this piecemeal. Of course, buying fully-cured rock from a reputable source you trust takes away this argument as you can add as little or as much at time as you want>> Am I just being pushed for sales? <<Is “your” friend…what do “you” think?>> Also, since Marshall is lighter weight, is the poundage weight equal to what is needed by another type of rock, or is less weight ok? <<The lighter more porous rock should provide more benefit/bio-filtration per pound than a denser heavier rock, yes>> I have had my tank up for a year. I have gone very slowly. <<Ah, patience! A very rewarding virtue here>> I have ONE percula clown, a brittle star, a few snails and hermits. I recently added my first corals, two tiny little frags. <<”Slowly” indeed…>> My other question. I have received so many conflicting information regarding tangs, from others. <<Ah well, the hobby is rife with opinion…and you won’t find it any different here [grin] >> Some say 75 is not large enough and recommend a 100g. In Fenner's book, page 304, he states at least a 50. <<…and then dependent upon species>> This book was revised in 2001. Has he changed his opinion on this since? <<Let’s ask him…Bob?>><Is posted... RMF> I hope he still agrees with that statement, since I would love a tang in my 75g. <<If you stick to a small aquarium hardy species, and overstock the tank, then yes, I feel you would be fine adding a Tang to this tank. I think either Zebrasoma flavescens (Yellow Tang) or Ctenochaetus strigosus (Kole Tang) would make a suitable addition>> One more question. <<Okay>> Since the tang will be in a 75g, will it be more prudent to have more open swimming area at top, or is it ok to keep stacking rock. (Remember I have 75-80 pounds) <<”More open swimming area” gets my vote>> On a final note, I was thrilled to find this site. <<We too are happy you found us>> I cannot read Mr. Fenner's book enough. It stays on my coffee table so I can pick it up whenever I want, and guests find it a lovely sofa table book. Stacey <<I’m sure Bob will be pleased to know. Regards, EricR>> >Better than Oprah? RMF<

Sponge... Adding A Dried Tree Sponge To A System... Not A Good Idea! – 09/14/07 Hi. Is it safe to put a dried Red-Orange branching sponge (Ptilocaulis sp) to a saltwater tank for decor purposes only? I have a 55 gal. FOWLR and I find it attractive to put one of these together with my live rocks. Thanks. <No. This is not safe. These can be quite toxic when they die and can wipe out your system. A dried dead one sounds like a recipe for disaster to me.> Larry <Cheers, Mich>

Clay in aquarium?    8/30/07Hi there, I've been browsing thru the site and it looks very helpful. I was wondering, i have a small clay pot which I'd like to put in my marine tank as a decoration, is this a bad idea? Could dust / particles be dangerous at all? <If it's an un-painted ceramic pot, it's probably fine. A lot of clown fish breeders use un-painted ceramic pots. On the other hand, some aquarists fear that heavy metals might leach out from the clay. There might be something to this worry since clay has a great capacity for absorbing heavy metals. Then again, some clays are highly valued for their ability to absorb, retain and stabilize heavy metals. So, either clay is toxic and to be avoided, or, we should be using it as a filter. Does that answer your question? LOL j/k Ok, seriously, if it's un-painted, commercially fired, well rinsed and hasn't been used for anything else, then I'd say it's fine (especially if this isn't a reef tank).> Kind Regards, K. <Best, Sara M.>

Making inserts for large aquariums, materials  – 06/15/07 Greetings! I've been checking out your site and am really stoked on you're wealth of information! I have built several large scale tank inserts over the years and I am always looking for new products. <You've seen the "natural" backgrounds made in Europe?> Currently we have a large insert project getting underway and I was looking for a texturing putty to apply to polyester resin forms. Typically we will sculpt a positive shape and apply many coats of resin an fiberglass over the form to make a 3/8" to 1/2" thick insert. We have used an epoxy coating in the past which is very tedious to mix and there are numerous curing steps after the application. <Yes... these are all I'm familiar with... unfortunately> Is there a polyester resin friendly putty type of product out there? <None that you can put underwater permanently as far as I'm aware> I need a product that is fish safe, sculptable, easy to mix and apply and preferably minor curing steps. The epoxy product we've used in the past is good for end result but very labor intensive. Just wondering if you guys have come across anything worth testing? Thanks so much for your time. Mike <Are you familiar with CRF's? Concrete Reinforced Fiberglass? For very large projects this is what we used for artificial habitat base. Bob Fenner>

Styrofoam, Next Time PVC, perhaps Starboard.   2/20/07 Hello! <Hi there MJ!  Mich here.>      I have searched high and low using specific search strings for this question.  "Is Styrofoam safe for inside the aquarium?"  I have a 200-gallon half cylinder that I placed some blocks of Styrofoam in to prop up the rockwork for aquascaping purposes.  I used 2" rigid wall insulation for this purpose.  The sticker on the insulation says that it is chemically inert.  My fish are healthy and my hermits love life.  Refugium is growing well.  Should I worry about this Styrofoam breaking down over time and releasing nasties into my tank? <Sounds like a nice system.  To be perfectly honest I don't really know the answer to this question.  I would be a little leery as I have kept this type of insulation in the basement and over time it gets a little crumbly and nasty.  That being said, if it's not causing you any obvious problem right now I think I would just leave it alone.  RMF comments?  <<Mmm, Styro is chemically inert... but does tend to fall apart too much to suit me. RMF>>  I do have a suggestion for the future.  PVC piping is commonly used to support rockwork and I think is a better option as it won't react or breakdown. There are multiple ways of doing this from actually constructing frames to simply cutting large PVC piece with a saw.  There is also a product called starboard that is used in the hobby and is know to be inert which is good if you are lining the bottom of the tank.  Good luck!  -Mich> MJ

Tufa rock and Mexican food <Anthony Calfo here whilst Bob makes his way to the land of Oz and a little magic on the Great Barrier Reef (as I understand it, the "magic" part is an all you can drink beer party after a week of diving)> Thanks for the unbelievably swift response. <that's easy for Bob... he types fast because he is usually incontinent from the amount of water and spicy Mexican food that he consumes> Well, the Tufa isn't in the tank yet so we haven't done any damage. We are growing a prolific crop of BGA though.  <skim aggressively, my friend and increase water flow if possible. A good dark cup of skimmate daily for a couple of weeks will knock out the BGA without you lifting a finger> Not enough $ to bring the LR load up to where it should be, I suppose.  <bummer about that Canadian dollar thingy> Is it safe to let the tank proceed with its cycle without any changes other than to increase the photo-period?  <sure, just go easy on the feeding an bio-load until more live rock possible> To siphon off the copious quantities of water necessary for mechanical removal will really stress my septic system as well as my wallet. The system is only two weeks old at this time with a 2"crushed coral substrate and a few pounds of live base rock. Usual drilled tank (most expensive gift I ever received), sump box, wrong inline pump, 79 degrees water, S.G. 1.023, Sal 31, yada yada yada. Thanks for everything. The improvements are proceeding forthwith (already returned a replacement silent one this AM.) Cheers, Fred. <best in your endeavors, my friend. Anthony Calfo>

Tufa has been removed Thanks for the informative response the other day.  <always welcome> The Tufa rock has been removed, not only from my tank but also from my property. The vendor kindly refunded my purchase price on the returned goods. <a good way to honor/keep a customer> This evening I was again reading the FAQs and noticed with alarm that I have one of the well advertised and less well loved Lifegard pumps. It is presently on its second motor. <yes... the "Not-so-stainless steel" shaft that leaks> It will not receive another. Given that the life expectancy of this circulator is certainly limited I am in the planning stages of replacing the thing. <a great pump for freshwater though> The manufacturers rate the capacity of their pumps in the face of various head losses. Without going to engineering tables, what do you use as a rule of thumb to add head restriction for 90s and other fittings in addition to the easily measured physical lift from sump to tank? <add one foot of head for each elbow, valve connection and ten feet of horizontal run in addition to the height> My tank is 48 x 18 x 20 inches and came equipped with a 1 1/2" standpipe. I built an 18 Gal sump to increase the water volume a bit and to have a place to add essentials. Would you be so kind as to recommend the appropriate MagDrive (as they are available locally) to hustle all of the water around at the required rate? <I believe that there is a mag 1100/1200 that would be quite comparable to your Lifeguard if you are otherwise pleased with the flow> I sincerely enjoy the fruits of your collective labors. Cheers, from B.C., Fred. <thanks kindly, northern friend! Anthony Calfo>

Wood in salt water tank?   8/11/06 Hey Crew, <Hey there!>         I have a 45 gallon salt water set up. It consists of local North East fish and crustaceans caught in NJ, and Long Island waters. I enjoy making realistic decorative environments. It has been running for two years. I have new miniature wood lobster trap which is unfinished. My question is can you put wood in a SWT? I know I would have to soak it for a while to get it to sink. Thanks for your help. <I wouldn't, but you could.  Make sure that the wood isn't treated in anyway.  However it a tank, just like in nature, it will start to break down.  It could also be a harbor for algae, bacteria, and start to pollute the tank.  In other words, it won't last long before it starts to have detrimental effects on the chemistry (not to mention visual) aspects of your tank.  I would try and find more inert decorations.  Have a good one, Jen S.> John M.

Aquascape... Mixing crab-eating morays, using a Jeweled Damsel from the TWA, Moray system/s, acclimating new livestock...   8/3/06 Morning, <Now the afternoon here... Yikes, got to "kick out the jams"... whatever that means> Just a quick question... or at least they always start out that way.  I'm looking at doing a 200gallon predator tank that will include both a snowflake and zebra moray eel, a Russel lionfish, and a couple of others. From reading your FAQ's, it sounds like in that large of an aquarium the two morays should be ok together?   <These two species, likely so> I also just bought a jeweled damsel on the advice of on of your FAQ's... since this fish will eventually get to be around 6", a good fish to cycle my new 200gallon tank and should be ok with a lion and the morays? <Mmm, likely okay to cycle, will get along> My damsel is pretty brown looking with the diamonds on his back... does this sound like a jeweled damsel to you? <Of mid-size/age... okay> Anyhow, my question.... Ok, my third question?   With a fish only tank, I'm thinking a crushed coral bottom hiding a small network of 3"pvc piping to create a more interesting habitat for the morays.  The pipe will open up in a two or three caves that I will make.  Sound like a good idea? <Shore> I just hope that a) a fish won't get down there and gobbled by the eel <Mmm, the two species listed are largely non-piscivorous... see WWM re Foods/Feeding/Nutrition of these two... I have penned, placed articles re...> or  b) something big doesn't die down there.  Would be pretty nasty disassembling my aquascape to remove the pipes to get a dead eel out.  Your opinion?   <Sounds pretty nasty> The real question is (this is number 4, isn't it?) am I ok using a nice black/grey slate to build up the backside of my tank and for the caves? <I wouldn't use slate in marine systems... too two-dimensional with all the drawbacks of same... too likely to have some chemically negative effect> I was thinking of using aquarium poxy to get a nice firm rockwork and like the appearance of slate.  I was also going to use about 100lbs of liverock to get a mixture.  Do you foresee any problems with this? <Yes> Just a note on the 'freshwater dip' for new fish.  Sounds simple, but maybe it is me that is simple? Haha. <?>   After floating the sealed bag in the tank to get the temperature matching for about 20 min.s, I then open the bag and slowly introduce some tank water via a cup without mixing store water into my tank.  When fish is ready, am I correct in saying simply dip the net with the fish in it into some room temperature fresh water for a couple of seconds and introduce new fish from net into my tank? <Mmm, one method... not one I'd use. Please read here: http://www.wetwebmedia.com/acclimat.htm and the linked files above.> Regards, Dave Brynlund <Keep reading. Bob Fenner>
Re: Aquascape   8/3/06 Thanks Bob... <Welcome> And did I mention I finally bought your book?  Why on earth didn't I buy it 3 years ago? <Man! I could've used that 28 cents in royalties way back... devalued now, rats!> What can you recommend as a cheap rock that is attractive? <Mmm, see the various etailer re what's available from the S. Pacific... in bulk, box order quantities...> One of the fish retailers mentioned travertine? (sp?) <Mmm, no... we have this on some of our floors... is made up of various chemicals... formed in nature by "swamps/hot springs"... you don't want this...>   It's white, really porous...  I've read a number of people using the slate for marine aquariums... I guess I trust ya! <Up to you... BobF>

Venus Flower Basket... biological old-timey bathroom sponges as decor   6/23/06 Good day Crew...hope all is well. <About as well as...> Might I have your insights on putting a Venus flower basket skeleton back  in the marine environment? <Mmm: http://www.abdn.ac.uk/~nhi708/treasure/venus/ a demospongian> Seems that they are made up of mostly fibre  glass <Silicate> so I ponder if there would be any concern housing it in a home aquarium  for a long period of time as decor. Thanks....take care. <Shouldn't be a problem... are almost entirely chemically inert... Will likely want to take out, "bleach wash" to clean occasionally (see WWM re: http://www.wetwebmedia.com/clnornart.htm). Bob Fenner>
Re: Venus Flower Basket  6/23/06 Thank you Bob, I'm glad to know I can use it in some of my saltwater set ups....I look forward to trying it. The link you provided does not seem to work, would you concur? <Mmm, works for me: http://www.abdn.ac.uk/~nhi708/treasure/venus/ > Thank you so very much for the advice, it's good to know. Be well. <And you my friend. BobF>
Re: Venus Flower Basket  6/23/06 There we go, that linked worked, I may have been doing something off,  prior. Thanks again. <Welcome> I look forward to trying this out in a marine environment, would you think down the line there would be some sort of breakdown present, after having it   housed for the duration of the aquarium being up and running? thanks. <Some deterioration over time, yes... but likely slow, virtually undetectable. Bob Fenner>

Driftwood problem  6/21/06 Hello crew, I love the site, it has helped me see how little I knew a few months ago. <Ahh, good... Justification for all the resource expended/invested> I couldn't find anything related so here goes:  I have a 55 gallon, emperor 400, Superskimmer, (2) MaxiJet 1200's, and about 50 pounds of LR.  I started out with the idea of an all local estuarine tank. <Neat>   I had a black sea bass and a rock sea bass <I hope these were quite small...> and many local hermits.  The local fish get too large and I decided to restart and let them go.  The big problem is, I had a big piece of driftwood (I know that was dumb) and some local calcareous rocks.   I didn't realize it, but little pieces of wood were breaking off and are all over the substrate. <Yes... interesting material, but needs to be carefully prepared...> I suspect the wood was lowering my ph. <Very likely, yes>   Now, I've switched to live rock with the idea of doing a more typical setup, but I am having a heck of a time getting this wood and other debris vacuumed out of the tank. <Needs to be so thoroughly "vacced" that I would suggest taking the tank down and rinsing and rinsing in a bucket in five or so pound aliquots> Substrate is a mix of aragonite and Tahitian moon sand.  Nitrates are sky high (80 ppm), and I need them to decrease before I add any fish or cool inverts.  Any advice for making this transition and getting this tank clean and healthy. Ammonia and Nitrite have tested at 0 since the initial cycle.  Its funny how little you know when you start in this hobby (and I'm a marine scientist). Thanks, Matt <I'd re-start... this is about the only way to clean out the vast majority of the wood and its ill-effects. Bob Fenner>

SW Lace Rock  ??    6/14/06 Hi Eric or Crew, <Daniel> I was wondering what are your thoughts on using lace rock in the salt water aquariums. Is there any special way I need to clean it? <Best to really "blast" it with pressurized water to remove organic material (most is dug up out of soil...). See below. I have half of my tank set up with live rock and thought it would be a good contrast to use lace rock on the other side. It is a 135 gallon fish only with live rock ..so far. Any info. would be great - Thanks -daN <Mmm, a chance for a more complete "answer" here... I am not a fan of using, or at least carte blanche endorsing the use of "lace, also often labeled/known as Tufa rocks" for marine aquarium use (though more so for some types of FW... e.g. African Rift Lake...) as the descriptive term is not accurate... Some of this rock is calcium carbonate based (principally), derived from sedimentary processes... perhaps from lime-rich hot springs (we've just installed travertine flooring in part of the house... similarly derived)... other sources for this material include pyroclastic volcanic ash that has solidified into rock... The largely calcareous material may be safe, adding carbonate (raising pH, alkalinity), and the volcanically derived material may be largely inert... composed principally of silicate (SiO2, Silicon Dioxide)... but both may have "other components" that may well be to a degree problematic, toxic. If it were me/mine, I'd either stick with "pure" sources of said decor, or at least have questionable ones thoroughly tested. Bob Fenner>

Aquascaping 01-01-06 Hello and thank you for your time, <Hello> I own a 29 gallon bowfront reef aquarium with approx. 8 lbs of live rock and 8  lbs of lace rock. My problem is that the rock I have bought is very dense and  square. I need to know how to aquascape to create a beautiful theme for my eyes  and a practical home for my inhabitants (currently 1 colony of star polyps and  one snail after the death of my neon goby). My live rock consists of a square  piece with a colony of green star polyps growing on it, and 2 rectangular shaped  pieces. I have a cave centered in my aquarium ( 12 in by 8 in) of lace rock with  a hole centered in the middle. I would love a theme of stacked rock with casting   shadows as a result by my power compact lighting. I know I need to buy more live   rock, particularly lighter and more varied pieces, but I need a lot of help with  exactly what kind and how to stack it. <Your best bet will be to search this site and many others on the internet for pictures of other individual's tanks. You can then borrow some of their ideas and make them your own. I would also suggest using smaller pieces as they are much easier to shape and position. I personally think a "lagoon" style would look great in a bowfront. All you do is make 2 stacks of rock, one on each end of the tank. This leaves the middle area open for your fish to "cruise" and it is a great break from the traditional "wall of rock" reef design. Another benefit is the ease of cleaning and increasing flow in a tank this style. My last piece of advice, never stack rock against glass as it will cause dead spots. Travis>                                                                 -B. F.

Painting on a Background (9-16-05) Hi there! Good evening, Leslie here with you this fine evening.> I am getting ready to set up a 60 gallon FOWLR system. I am considering painting on a background. Using your search feature, I found that you recommend using water-based latex paint. I was just wondering if you had a recommendation on the type of brush to use. <I find rollers work well. I use a thickish one.> Also, if there are any drawbacks or risks associated with painting on a background, could you please share them with me? <Nope there are no risks I can think of. I do however have a few tips…  Be sure the tank back is clean and dry before applying the paint.  The paint should be applied to the outside of the tank. Let the paint dry thoroughly between coats. Do also be aware that the paint can peel and chip especially with the use of hang on the back equipment.> Thank you in advance for your counsel. Pat < You're most welcome, Leslie>

Driftwood in Marine Setup  8/16/05 Crew- <Craig> I have a 30 gallon mini-reef with a 5" DSB. Would you advise removing a sizable piece of driftwood that has been in the system since setup (approx. 8 months)? <Mmm, if it's taking up space you'd rather use in another way...> The tank is stocked with 45# of LR, one Fu Manchu lion (3"), one four-stripe damsel (2"), and one blue velvet damsel (2"). <Surprised the Lion hasn't sucked up the damsels as yet> The invertebrate life includes 2 dozen Nassarius, a handful of Trochus and astrea, and a recently (~3 weeks ago) added colony of green star and button polyps. I do not have water quality problems and I am confident my filtration and lighting are all adequate (from reading and researching your site and others). The driftwood was purchased from my LFS with assurances that it would be fine in a marine setup. I am not so convinced these days, and have concerns that as the system continues to mature, the driftwood will contribute excess nutrients to my system, thus promoting nuisance algae and depressing my pH. <Likely so> Could you spell out the probable impact of driftwood on a marine system? <Mmm, let's see... the descriptive term "drift and wood" is too vague... there are definitely woods that I would not employ in captive aquatic systems (fresh, brackish, or marine), some that "if cured" are safe... even gorgeous... but do all to some extent continue to decompose chemically, biologically... as you state, mal-affecting water quality to extents> The driftwood has a slate base, and removing it will definitely be a significant disturbance on the DSB. Should I drain the tank halfway into a quarantine, moving the livestock to this tank before removing the driftwood and allow time for the system to settle back out? <Yes... a very good idea... Likely a giant mess...> I am not really into making extra work for myself, but given my circumstances, what would you do? <I'd plan on having to drain the whole tank, make a few change-outs of water to remove the likely anoxic mess that will be about the base of the wood> If my concerns are non- issues, that's alright, I would rather be safe than sorry. You know, a Conscientious Aquarist. <!> Thank you for your time Craig     <And you for writing, sharing. Bob Fenner, another one>

Sculpted backdrop for 120 gallon tank 8/9/05 Any suggestions for building a background that will sit behind the tank ( wont have to be limited on material as it will not be in water ) <Oooh, yes... some really neat possibilities here... can be fantastic or attempt to continue or expand on a theme inside the tank itself...> I wanted to build a rock wall with a diver on it and then the top would be a sandy beach with a Lego boat backing into the water. <Neat> I plan top use some of the base gravel that will also be in the tank to blend the two together. My question is if I need to fill it all with clear decoupage or some material to mate it to the rear glass of the tank will it look realistic? <Mmm, likely not... though once it's all up and placed, you might want to add some matching lighting over it to blend in with the tank> Any suggestions.   <Do send a pic or two! Bob Fenner> Thanks for the notes, I'm off to the workshop <In our day we made many such dioramas... for Public Aquariums... some with mirrors on their walls that gave the impression of infinite depth... all were great fun, interesting projects. Enjoy yours! BobF>

Plastic bins as reef structure? 8/6/05 Found some nifty black plastic inter-locking storage bins to support my reef structure.  They are manufactured in Jordan and are for office storage.  My chances on the dyes staying intact and inert......?????  < I'd say they are fine if you like the looks and think they are structurally what you are looking for. > Can I soak them in saltwater for a couple of weeks and determine anything?  < Maybe but I'm not worried. > Not food grade, ok... what are my chances. MJ <  Blundell  >

Crabs and shells from ocean 8/4/05 Hi Crew, <Christy> Can I put hermit crabs or empty shells from the ocean in my saltwater   aquarium?  Do I have to do anything to the empty shells first?   Thanks for any help you can offer. Christy <Please read here: http://www.wetwebmedia.com/clnornart.htm Bob Fenner> How to build a live rock cave? 8/1/05 Hello, Can you please point me to explicit instructions (diagrams might help) of how to build and support a cave of live rock?  I've read that such caves should be reinforced with PVC, but am uncertain how to do this exactly, and how to support the whole structure -- e.g. does it require a complete under-sand scaffold?  I'm new to this hobby, though have read a lot so far.  The tank is 40-gallons (it has 36" longest dimension), we'd like a cave about 12" deep, 10" high, with sand on the floor. Thanks so much for any info you can offer! <Mmm, please read here: http://wetwebmedia.com/lrplacingfaqs.htm and the linked files above... do give a look/see at Anthony (Calfo's) "Book of Coral Propagation" for graphics, more/better explanations. Bob Fenner> Wood in saltwater Good Morning! <Yawn!!!> Once again I've come by to pick your brains! Kind of an odd question but, I have a 75g saltwater tank in the works and I'm wondering if you can put wood inside the tank? (Not driftwood BTW) Does it need to be sealed, and if so what would I seal it with? <Mmm, not a good idea in the long haul... coatings break down... pollution> Something like a polyurethane varnish?  <My favorite material for furniture!> I have a really cool and unique idea for decor in there but I want to know if this will be safe for the fish... Thank you once again for your most valued help!!! Barbara <Worth experimenting perhaps, but realize you will likely have to discard all the contents of the system when the finish fails. Bob Fenner>

Artificial turtle grass? Mr. Fenner, < Blundell here tonight. > I am looking for a supplier of artificial turtle grass. Can you help me?  < Artificial? You mean plastic? I'd maybe look into having a store order you this http://www.naturesimageonline.com/NI-125.htm or just look in local pet stores in the freshwater section. Unfortunately I don't know any product that is specifically made to replicate turtle grass.> Thanks, Gary < Blundell >

Base Rock Query 4.26.2005 What do you call "dead" live rock and can I sell it? I have about 150 lbs of it. <Dead Rock is an expression that is applied to Live Rock that has been dried, and the symbiotic life has perished.  It can be re-colonized, but can take years.  Many aquarists purchase this dead rock/base rock to use in refugiums, etc.  Good luck, Ryan>

Mirror finish on aquarium wall 3/22/05 In using the search tool, was not able to locate anything more about mirrored tint, other than on the back. I have a Question regarding the use of one-way mirror tint to put on aquarium. Would this in any way hinder marine fish? I find that as I'm cycling the aquarium using damsels, I have a green damsel that likes to hide under the rock, they all hide when the lights are out. Also have read that several species of fish are shy. Would putting the tint on the front and sides assist in having them swim around instead of rushing to hide anytime someone goes near the aquarium? And also help in reducing the stress on them? <I agree with the notion that the fish will be less shy and less stressed if they cannot see outside of the tank, however seeing their own reflection in the walls of the tank would lead to disaster. Most fish will act aggressively toward their own reflection as if it were another fish! This will lead to more stress as well as injury as they try to attack the reflection.> I'm thinking it would be a good idea, and also an aid in additional light getting to the bottom of the tank with the reflective nature of it. Plans are eventually to upgrade to 48" 4x65W 50/50 10k/03 actinic with moonlight for a 24 hour lighting on 55 gallon 48" long and keeping moderate lighting requirement corals.  <Using quality fixtures with well designed reflectors is much more important in ensuring good light penetration through the water. Reflective surfaces inside the tank would contribute little (aside from the problems with the fishes). 4x65W PC lighting is plenty of light for most corals.> Much appreciate the assistance, and the presence of this website, I like so many else have mentioned, only wish I seen it before purchasing the skimmer, a SeaClone 150. But, I will be getting an Aqua C Remora soon, as well as 45lb live rock. Thinking the SeaClone will handle the curing of the rock in a Rubbermaid 16gallon container. Other filtration being used are Marineland Penguin 350, Fluval 204 with bio-media and pre-filter foam. <Thanks for the kind words about the site. The aqua-c will serve you much better than the sea-clone. I would cycle the rock with the aqua-c and then replace the sea-clone after the rock is cycled. The power filters that you mentioned are fine, but must be cleaned AT LEAST weekly.> Have about a layer of Aragamax and crushed coral with a layer of fine sand on top of it? 200W heater, also getting another 200W to use while cycling the rock and getting temperatures right for water adding and 10% changes weekly, using Oceanic Salt. In your opinion, do you think I'm on the right track of switching from South American Cichlid over to a marine aquarium with "moderate" coral? The coral are probably another six months to a year before adding.  <It sounds like you are very much on the right track. Be sure to maintain alkalinity and calcium. Kudos on your patience. Running the tank for a few months before adding corals will give you time to learn and practice maintaining water quality and will add to your success! Best Regards. AdamC.>

Questions on Rock Date: Fri, 11 Mar 2005 Hello Mr. Fenner <Just Bob please George> My name is George Vitale. I am a 45 year old male who is changing careers from welding to teaching school. <Outstanding> I have always enjoyed biology and most especially marine biology. My wife and I recently got back into aquaria and I am reading as much as time will permit. I am very grateful and thankful for your book The Conscientious Marine Aquarist which I have read in its entirety and I am recommending it to others. <Ahh, glad you found it useful> I am writing this email hoping to pick your brain about lava rock and Florida mined limestone. In your book you mention that lava rock has long term negative effects on the system. Would you please tell me what those effects might be? <Principally the possibility of metal contamination... but secondarily the fact that this material is "too smooth" (siliceous) and not calcareous... that its presence won't add much to biological filtration or dissolve, rendering calcium, carbonates... buffering pH> Is it the concern over leaching phosphate, and if so would macro algae keep up with those levels? <It might> Also what are your thoughts about using limestone in a large sump (300 gallons) for the biological filter for a 150 gallon tank? <Can be done... crushed coral and other "sea material" is better in that it releases a proportionate amount (about three times) magnesium... other useful molecules> Any help that you might be able to give would be much appreciated even when unable to repay the kindness. George Vitale <Thank you for writing, congratulations on your career change. Bob Fenner>

Eel and Shark 3/11/05 Hello, Can you tell me if Lava Rock would be ok in a tank with a Snowflake eel and bamboo shark? <likely safe... but always some risk/extra algae with terrestrial rocks><<Mmm, too sharp... little help with biofiltration, water chemistry. RMF>> My tank is 65"X25"X25" My filtration has around 100 lb of live rock in my sump 1 canister filter 1 protein skimmer. I can't seem to find anything about Lava rock in fish only salt systems. Can you please help me. Thank you <go to our index page at www.wetwebmedia.com and simply type in "lava rock" in the Google search tool. Enjoy the journey. Anthony> 

Painting underwater? Nope/ 2/25/05 Just a follow up from yesterdays email.  I will go the route of working with glass to make the overflow. My question is, I would like to have the glass be opaque to hide the bulkheads, water churn, etc. Can I use that aerosol spray on the glass that makes it look frosted?  <yikes! no... toxic risk, and not durable underwater. Just ask for art glass instead... any color, texture, opacity, etc> Do you know if it is inert once cured?  <scary list of chemical ingredients> Or is there another solution that would accomplish the same thing?  <art glass like stained glass artists use> Also, not sure if you saw the second half of my email yesterday... would you mind emailing the portion of your book that covers the horizontal overflow. It would be much appreciated.  Thanks! <buried with e-mail/work my friend... and simply have not had the time to dig through shelved archives for the digital file copy. My apologies. Anthony>

"Lava rock" Good day, I obtained an aquarium which was used for many years as a freshwater tropical aquarium hosting parrot fish and Malawi's.  The aquarium has a lot of "lava rock", which is a reddish-brown colour, in it.  I want to change the aquarium to a marine aquarium.  Can I use this "lava rock" in the marine aquarium with African live rock?  If yes, should the "lava rock" be cleaned and how. Thanks. Willie Deysel <Good question... well, most volcanic, igneous "lava" rock is not to be carte blanche trusted in marine aquariums... due mainly to concerns with possible chemical leaching... but... as this rock has been in long use in an aquarium application (albeit freshwater) I am inclined to trust it enough to try and use it. It can be "cleaned"... likely should be... perhaps as far as bleach washing... Please read here re: http://www.wetwebmedia.com/clnornart.htm Bob Fenner>

Terrestrial rock marine safe? 1/16/04 This is a follow-up to my original question I posed on your forum one year ago, about using Lace Rock as base rock. Dis-illusioned with the reply's I received, I decided to use said rock as base. The Lace rocks have been in the tank approx: 1 year and are now covered in red coralline, (actually, some even have more then my Fiji rock), and tons of mini feather dusters. At this stage, it would be hard for a novice to distinguish between this rock and "live" rock. <superficially yes... and good to hear overall> After many attempts, I have yet to see any coral/anenomes settle on any of the rocks....even after I have placed them on the rocks, they eventually (with hours) move. <it is an unnatural surface... many marine creatures are very sensitive about the matter, to the extent that certain larvae will only settle out on specific species of other matter (types of corallines for example)> I will follow up with more info later as I will keep experimenting.... <thank you for this input/follow-up. Indeed, we assume some risk with using terrestrial rock. Seems harmless here but still a bit of a challenge. Anthony>

Paint question... <Hello Rich> First off, thanks for all the help you give everyone. I know I appreciate it. Here is my question. I just finished putting some touchup paint on to a rock wall that I was building using lace rock, egg crate and great stuff. The little great stuff that I did need to paint I used an outdoor/indoor gloss acrylic enamel paint from a hobby store. It's water based so I assumed I was ok since I had done some research into the paint prior to buying it. This stuff was attractive because it was listed as water resistant. Well after using it, my daughter read the label (I know, I didn't) and yelled at me because the label does state that this paint should not be used where food comes in contact with it. It also said not to use within 2cm where your lips may come in contact either. So now I am concerned. The bottles are 2 oz bottles and if I used a total if 1/5 of that 2oz total would be a generous estimate. I used very little to say the least. It's going in to a 220 tank, should I be worried? Should I seal with some other coating? The exact brand is PLAID, plaidonline.com black, real brown, and grey. Thanks for any advice you can give.<Water resistant does not mean waterproof.  That paint will probably dissolve in due time.  The only paint I would safely recommend would be an epoxy based paint that is allowed to cure the correct amount of time before submersion in water.  James (Salty Dog)> Rich Hunziker

PVC Use in Aquarium Hello everyone, and Happy New Year! Does it make sense to use PVC pipe as sort of a skeleton for aquascaping?  I am building two towers of live rock, and I thought I might use PVC pipe in the center to hold them together (i.e. mount the PVC onto a flat board of some kind, burry the board underneath the substrate, and drill holes in the pipe so that I may use ties to hold the rocks in place).  Make sense?  What might I use to mount the pipe to the board? <Use a drill with a masonry bit, in combination with a PVC structure and fuse it together with zip ties.  The rock can be easily drilled to create holes- Then the zip tie should be inserted through, and secured to the tower.  Encrusting algae will cover anything in time!> Thank you very much, I always appreciate your insight! <Good luck, happy reef-building! Ryan> Daniel

Painting acrylic tank If so, what sort of paint would be safe to use? <My understanding is that you can paint acrylic tanks with acrylic paints.> Thanks! Jeff -

Waterproofing Styrofoam - We are currently making an accessory for our aquarium.  The accessory will be made of Styrofoam.  We have heard that epoxy is safe for use in aquariums but need an epoxy that is easily spreadable. Please let me know if you know of an epoxy that spreads easily or if there is another product we can use. <Well... I would think that fiberglass resin, which is really epoxy resin... the fiberglass is a secondary application to the epoxy resin. The resin alone is quite spreadable as well as chemically "hot" which means you'll need to test with the Styrofoam you're using. You might find that stock epoxy resin melts your Styrofoam. Just give it the full amount of time to cure and work with it outdoors and you'll be fine.> Thank you. <Cheers, J -- >

Red lava rock? hi, <Hello there> Thank you for the response about my lighting and gorgonian question. <Welcome> In the past I had bought some porous rock from the local fish store to supplement the live rock, and it's done very well and is covered with polyps and coralline algae.  I recently bought some more rock - but got a porous red lava rock without realizing it wasn't what I had bought originally.  Before I introduce it into the tank, I was hoping to get an opinion if this is ok or a mistake!  This is a 30 gallon reef tank w/ lots of polyps, soft corals, clownfish, pajama cardinals, etc. Thanks, Ben <... Have seen/experienced red lava rock that was both fine for marine aquarium use AND other types that were disastrous chemically, physically... I would at the very least "do a bio-assay" with boiling a bit of water with some of this rock in it, letting it cool, and subjecting some fish and non-fish life to its presence for a few weeks before placing it in my/your main/display tank... You can get/use test gear for iron content... The real, short answer is I would not use it. Bob Fenner>

Can sandstone be used in a saltwater tank? >>>Hello Monte, Sure, you can use sandstone. Don't expect it to transform into true live rock though, it's much too dense. Also, if you're talking about a reef tank, or any tank where coralline covered live rock will be introduced, the sandstone itself well become covered in coralline algae eventually. So, might as well just use live rock. If you're setting up an "old school" fish only tank with no live rock, then coralline algae will not be an issue. Jim<<<

Aquarium backgrounds Good A/F                     I'm  looking to paint the back of my tank. Do paints differ for glass made for  aquarium. Are there any type of texture paints or type of paints out there  specifically made to enhance the color of fish?                                                                        TY <I like water-based latexes... for ease of application (best applied when tank empty, laid down on...), lack of fumes, ease of removal, permanence... black and darker blues are my fave colors. Bob Fenner>

Algae Aquascaping? I have seen salt water tanks with macro algae purposefully placed in for a more natural look. It looks nice, I'm just wondering if it is a good idea. << I think it is a wonderful idea.  Better to have than coral (but don't tell Calfo I told you that). >> I have a 125 gal. that is going to be a reef tank. Would it be ok to use some for aquascaping in a tank with corals? << Oh it is highly recommended that you do.  It provides many benefits. >> If so, what kinds of macro algae could I use and how far away from the corals should I keep them.<< My algae and corals grow right on top of each other.  I would use any of the Dictyota species, and most Caulerpa.  Just not C. racemosa because it is a little too prolific of a grower. >>  A blue tang is on the list of possible tank occupants. I have a feeling it would eat any of the macro algae's placed in to the tank even if supplied with adequate amounts of Nori to graze on.<< Even more reason to have the algae, it provides a great secondary food source. >>  Any input is appreciated. Thanks, Shauna. << Hope it all works out well. >> <<  Adam Blundell  >>

Re: Algae Aquascaping? Lol, I won't tell Calfo. << That is for the best. >> What a coincidence, my algae is growing right over the top of my live rock like it does your corals, who would of thunk it :) I thought it would be a great for tang grazing I just hope it doesn't eat it all before I have a chance to enjoy it.<< Yes this can be a problem.  Here is an idea (although not the most visually attractive idea).  You can place plastic baskets over your algae in some areas to prevent your tangs from eating it all.  Just get some of those green plastic baskets at the supermarket which they use for strawberries.  Then move the baskets around every week or so to cover another patch of algae. >> I should probably keep some extra aquascaping algae on hand for this reason. << Another advantage to having a sump. >> I wanted to make my tank inhabitance feel more at home, any other ideas that would achieve this? We already have a DSB, lots of live rock stacked around acrylic shelving supported by sturdy PVC legs. It creates lots of hidey holes, spacious caves and a cavern behind the LR stack that you can see in to. We are going to add a wave maker and now the algae, corals are coming soon as well as better lighting for them, moon lights, different stages for the lighting to simulate sunrise and sunset. We saw this on a couple of tanks and it looked pretty cool. The people that did this both said they noticed better coral growth and color when they started the different light stages. Any other creative ideas is appreciated, thanks again,<< Well I'm not one to ask for help on "creative ideas".  What I do is throw a bunch of stuff in a tank, and hope it grows and looks good.  I really like hands-free natural tanks. >> Shauna <<  Adam Blundell  >>

Re: 150 gallon fish only tank Thank you for the advice Mr. Fenner, I appreciate very much the time and effort you and your team put into helping rookies like me out.  By the way, I'm a San Diego resident, and the fish store I mentioned in my last email is Octopus Garden.  Your friend/tenant Ron is an...interesting person. <Ah, yes... an original for sure>   My question is do you know a good place around here to get good aquascaping supplies?? I was planning on using lots of live rock, and maybe some synthetic corals.  Also, if I do run a DSB, can I use beach sand from, say, La Jolla shores?.  I can't wait to design and build the interior of the 150.  <I would skip collecting your own sand unless you have a good deal of time to prep. it (rinsing and drying mainly... to avoid pest and pollutants). The aquascaping supplies can be had through local retailers like Ron and Aqua fauna/Aquatic Warehouse... or you might want to make some contacts through the local marine society, trade or hoof it up to L.A. sometime with them for a buy-a-thon. Bob Fenner>

Are Non Living Red sea Fans Aquarium safe? 4/28/04 Hello: I recently purchased some Red sea fans (non living, decorative) to use in my aquarium.  I was told by another person that these cannot be used in the aquarium because they will fall apart. I was also told that the Red portion of the Sea fan was the animal. Are these non living sea fans aquarium safe? Thank you <it depends... if the tissue has been stripped away and the gorgonian (woody) stem has simply been dyed or painted... then it may be safe. If there is still dried red tissue on it... then there will be some rotting. If the sea fan was packaged wrapped in plastic, then I suspect it was/is safe. Anthony>

Are They Safe?  >Hello:  >>Hello.  >I purchased some Red sea fans (non living) to use as decorations inside my aquarium. Someone told me that these are not aquarium safe because the Red portion of the sea fan is the dead animal and will fall apart in water. Are these sea fans aquarium safe? Thank you  >>Hhmm.. well, if you purchased them from an aquarium shop, where they're being sold with the express purpose of being used in aquaria, then even if they *did* fall apart I wouldn't worry. However, if you purchased them anywhere else, then one has to wonder if they've been treated with anything. That would be of greater worry than something that grows in the sea coming apart in water (unless we're talking certain other living organisms, another issue entirely). If you purchased them at, say, a novelty shop, then I cannot recommend using them. Marina

Lava Rock for marine tank? 4/6/04  Do you guys think lava rock should not be used at all in a marine aquarium?  <it can be used... best in large tanks with regular water changes and strong chemical filtration. Not so much out of fear of contaminants, but rather to control the excess algae likely from using dead/uncolonized rock>  I have a fish only tank, and I plan on aquascaping with Live Rock, using Lava Rock as the base.  <you might try building a hollow structure (sawn milk crates or a PVC structure/shelf) to avoid dealing with (nuisance) algae succession on dry/dead (lava) rock>  If I use Live Rock as the base, won't those base rocks die due to no light, and release ammonia?  <ahhh...no. rock rubble zones are deep in the wild my friend. Like... tens of feet deep/thick in the ocean! :) I strongly encourage you to use clean, cured live rock in quantity for a natural and stable system>  Thank you very much for your time! Daniel  <wishing you the best of luck, Anthony>

Lava Rock for marine tank? II 4/6/04  Anthony, Thank you very much for your quick response, and insight!  <always welcome>  One other thing- Like most of us, I am learning as I go, with many mistakes being made along the way. I am taking your suggestion of using PVC pipe for my aquascaping (building two 'towers').  <it is a good way to build large, attractive structures that do not weigh or cost too much (if solid rock)>  I used a piece of PVC pipe once in my quarantine tank- and all the fish died.  <there must have been some contaminant on it... PVC is patently safe>  I found that the PVC pipe had a very, very faint smell of oil...(I know, YIKES!) How can I 'cure' PVC pipe? Boil it?  <no need to. Clean PVC is completely safe. New pipe can generally be used right off the shelf. Do rinse to be safe. Your incident was an unfortunate fluke (someone spilled something on the pipe at the warehouse perhaps)>  Thanks again, Daniel  <best regards, Anthony>

Lace rock and holey limestone 3/29/04  Greetings crew,  <greetings>  While performing my daily ritual of reading the daily FAQ's I noticed Chet Andrews question about lace rock. I'm thinking it may be what I have leftover from my freshwater days, and if I could chunk it in my 125 FOWLR it would be nice.  <not worth the risk, albeit small>  The stuff I have is gathered locally (central Texas) and is sold as "holey limestone". Please see attached photo.  I still have the 3 pieces pictured, and thought they would be fun for my wrasse and pseudo to play in....that is if its ok to put them in. Thanks! Emo  <my advice is the same as stated in the message you cite: the rock is not recommended as it is of undefined composition/quality. Problems can range from harmless but messy fast dissolution to actual contamination depending on how/where it was collected on land (deposits, pollution, etc). Terrestrial rock does not get my vote here for your marine aquarium. Anthony>

Lace rock testimonial? 3/26/04 Hi Crew, I wanted to reply back to the question below, but couldn't figure out how.......maybe you can help.. ----------- I have personal experience using "Lace Rock", (FYI: Its a lava rock that has a lot more "pores" then regular weight lava rock)..... I have used it in both my 165 and 85 gallon reefs as a base rock. They work great as base rocks. <Hmmm... there are advantages and disadvantages to using such dead rock, the latter (disadvantages) including the fact that the matter is uncolonized and in many tanks will first be settled often by nuisance organisms. Furthermore, studies have shown that "culturing" live rock really never does compare to wild rock in terms of quality/bio-diversity. Still... it does have places/uses> I have tons and tons of worms (typical small feathers) "growing" on them. They are not calcareous, and thus no "boring" animals will be found. <this is not correct... the rock is calcareous> They will grow various forms of algae, but I have yet to find coralline type on mine (been in the tanks for approx: 1 year)..... <this is a common problem... slow to colonize> They don't leach (as long as they are cleaned before use). <yikes! another incorrect and unqualified statement. These and any mined rocks practically are of variable quality. In some areas of given deposits, there can be considerable contamination> Bleached, sun dried, and then rinsed out multiple times.....(and repeat). I don't think boiling them would hurt..... <agreed> They will not/not good host anenomes or soft corals, due to the extreme sharp (even down to a microscopic level) edges on the rock. <this is incorrect... and a bizarre statement> As an overall rock to use as base/foundation for "live" rock. I personally recommend this rock, as it is cheap, available everywhere, and most important (for me), has zero impact on the destruction of natural coral reefs. <I'm not sure why/where this testimonial is coming from... but it is grossly in error. This last statement most of all. Lace rock is mined from ancient reef formations which are a non-renewable resource (dead). Live rock is a living and renewable resource of vast quantity/potential. Getting the facts straight :) Anthony>  

Lace rock" and "holey limestone" 3/27/04 Greetings crew, While performing my daily ritual of reading the daily FAQ's I noticed Chet Andrews question about lace rock. I'm thinking it may be what I have leftover from my freshwater days, and if I could chunk it in my 125 FOWLR it would be nice. The stuff I have is gathered locally (central Texas) and is sold as "holey limestone". Please see attached photo. I still have the 3 pieces pictured, and thought they would be fun for my wrasse and pseudopod to play in....that is if its ok to put them in. Thanks!  Emo <using terrestrial mined rocks is a matter of variable risk. Even with carbonate substrates like this, their "safety" is not assured as some are of risk depending on where in the deposit they are minded from aside from issues of pollution from land-based/human activities. If you intend to use it... test it in a QT tank with a hardy fish first perhaps. Anthony>

Using Dead Coral Skeletons I have acquired some large coral skeletons from a marina development site - they are very clean and white & have been in the sun for months. Is it ok to add it to an established tank all at once (there is nothing living on/in them so no die off)? If not -why? Jeremy <Well, Jeremy- there are a lot of reasons why we don't recommend using un-prepared coral skeletons in aquaria. Sure, there might be noting living on them, but there is also the potential that they have been exposed to toxic compounds that can slowly leach into the water. There are no guarantees. The preparation of coral is a careful process, that involves multiple steps of bleaching, etc. It can be done by the home hobbyist, but you really need to test as you go. Do a search on the WWM site using the Google search feature to hear more. Good luck! Regards, Scott F>