Marsubfaq8

FAQs about Marine Substrates 8

Vacuuming Substrate, Algae, Dead Fish, LFS Water Testing II - 05/30/06 Eric, <<Debi>> Thanks for your reply and in answer to your questions 1) No, I don't filter the water I get from the LFS as I assume they are doing that. <<One would think...>> I have however since this started began to get my water from a different one than the first and the story is the same. <<Still worthwhile to test this water yourself>> 2) The substrate is about an inch and is very fine. <<Should not need to be vacuumed then...assuming good water flow within the tank>> The goby doesn't seem to have a problem sifting it, it is just that the top is brown (could this be algae too?) <<Yes>> and always looks dirty and although I have the skimmer, and two power heads, one a Seio 600 or 650 whichever it is and one an Aqua Jet 600 the junk that does end up on the bottom doesn't suspend much if at all. <<...?>> I tried recently adding an AJ400 to close to the bottom to move that more but it seems to heat the tank up too much. I try to keep it at 79-80 and it was heating to 81 with the new power head. <<This is not too "hot" in my opinion>> I live in a very hot area of the country and although I have literally several tons of air conditioning the tank still seems to be affected by the warmer weather and moves up from 79 to 80 without the additional power head. <<Indeed...I am in South Carolina and understand well the temperature issues of hot weather. Perhaps you could position a small fan to blow across the water at the surface of the tank for some evaporative cooling>> It stayed at 79 until the weather warmed up. I didn't really want it to vary by more than a degree so I unplugged the third power head. 3) I have lots of testing equipment and the test results I quoted are mine with confirmations from the two LFS. So I tend to think they are correct. That would make three opinions on the accuracy. <<Understood...but my concern is the test values of the water BEFORE it is added to your tank>> 4) Yes I have tried running carbon and/or Poly-Filter (one and both at different times) in a hang-on back power filter and didn't see any change in the fish's longevity so I am no longer doing that. <<Troubling remarks...but most any system will benefit from continuous use of these medias>> On the calcium level I have read about alkalinity and calcium until my eyes cross, but I don't know what to do about the high number as I don't supplement the calcium it is just that way and doesn't seem to come down much at all. <<Then either your make up water or your test kits are suspect>> Do you know how to lower it; would adding buffer alone like from the number one bottle of B-ionic and not the calcium? <<No, don't do this. The calcium should fall on its own/return to balance from the water changes...unless your LFS is "spiking" the water you purchase there>> I bought some of that a while back thinking I would need it, but never did, so I haven't used it, only the buffer part, except a couple of times to try to raise the alkalinity. <<In your system, with the livestock you have listed, water changes alone should handle replenishment/balancing of your trace/mineral elements easily...something doesn't make sense here>> I did not know if this was good to use just that one buffer part so I discontinued that. <<Good, as just stated, water changes should easily handle your tank's needs re>> So far as the water changes I would love to change less often, I have started the twice a week regimen in order to maybe find out what my problem was with dying fish thinking maybe that would be better. As I read this site there seem to be various opinions on what should be done on that. <<Agreed...and on much everything else as well <grin> >> I too have thought of something poisoning the fish but have no clue why the goby hasn't been poisoned yet if that is it. <<Any common denominators among the fish that perished?>> The blenny hasn't been with me very long so I am not sure what he will do. If he isn't eating the algae that I think is hair algae does that mean it is something different and he won't eat it or is he that picky? <<Many of the fish (and other organisms too!) we acquire as "biological controls" turn out to be something less than expected due to individual/behavioral differences...often brought about by captive life. Chances are a different blenny would clean up the algae...or not...>> That's all I can think of for now, thanks for your help. Debi <<Still think you need to test the water from the LFS...and review in your mind/try to link any "happenings" around the time of your fish deaths. Regards, EricR>>

Opinion on..... outdoor coral beds - 05/15/06 Bob we met at the NextWave at our DFWMAS club in Irving Texas. I was very impressed with your incredible first hand knowledge of the Marine aquaria industry. Which is the reason for this email. I live in Fort Worth but not in the city limits and have no restriction on the 4 acres where I live. There is a 2000 sq foot house also available. Seeing how your from Cali I thought you might like the choice of name for my new adventure......Ripple AquaSource... <Heeee! Have had their wine on occasion...> it's also one of my favorite songs by the "Dead"...the other one being Cassidy which is my daughter name. My wedding song was Sugar Magnolia <Seems reasonable> I would love to ask you a few questions if that is possible, I do like the good folks at Garth and there projects. <The singer or GARF?> The cool thing about this I plan to fund it with a gas lease I have. Funny story lived here 21 years and out of the blue a guy shows up with a gas lease. too funny. I do like the idea of funding this from some unexpected funds from something underground to something underwater. thought about making a 400 foot wall around the front of my place out of DIY live rock know where I can get my hands on 20,000 or so pounds of crushed coral and oyster shells cheap?? <Mmm, yes... likely... Call around the "local" sand and gravel plants re... ask them how much to deliver...> I lost the link on the guy in Ohio that has done this if you know it please forward... Pizza and Beer Robert Barrett <Now you've got my attention. Cheers! Bob Fenner>

Sandbed maintenance 5/14/06 Hey guys, <Hello> I just want to say thank you for all the problems you have helped me solve in the past. I have noticed that my sand bed is disappearing. I have a 55 gallon and I bought 3 20lbs water packed AragAlive Bahamas oolite to start off. My tank is about 1 yr and half old and now my sand is starting to diminish. <Common occurrence, dissolves over time, helps buffer the water.> If I need to add more sand I would like to get the finest due to the natural look of the ocean bed I love and my sand sifting creatures. <ok> Would I have to get the water packed Arag alive or can I buy the dry packed sugar sized sand? <The water packed stuff is no better than the dry in my opinion.> How much should I add at a time and will this screw up my ecosystem happening on the sandbed? <Add a cup or two a week, this allows sand bed creatures to migrate to the top without getting smothered.> Thanks Joe <Anytime> <Chris>

Adding Substrate - 05/09/06 Hello all. <<Hi Ryan.>> One quick question. What would be the best method for adding substrate to an established reef aquarium without disturbing the rockwork and burying anything? <<When I've added substrate, I rinse it, then fill a 'scoop' (cup, net, whatever) with a small amount of it. With reef gloves on, I reach to the tank bed, and sprinkle it where I want it.>> Thanks so much! Ryan Mullinax <<Glad to help. Lisa.>>

-Sand and bulkheads- - 5/7/2006 Hello crew! I have two situations today that I hope you can help me with. <Certainly> Situation number 1: I'm starting up (another) new tank, and I am using Nature's Ocean fine sand (not live sand). I didn't realize it until I had already added it, but I'm supposed to rinse this stuff. Now the water's all cloudy and full of gunk. Will this settle in a day or two, or do I need to empty the tank, rinse the sand, and start all over? I don't have enough salt at the moment to do that, so I'd half to wait a day or two regardless. Maybe running a filter on it would help? <The sand "dust" will settle within a day or so, and running an extra filter will help clear up the tank, just check and clean your pumps powerheads etc after it settles to ensure they are not clogged with dust either.> Situation number 2: I had a tank (yet another) drilled for bulkheads. One 1.25 drain (was supposed to be 1.5 but they got it wrong) and two 1" returns. Now I see that all the bulkhead sizes appear to be too big. One inch seems to mean "inside diameter" and my holes are only 1" so...what can I do? Do I just have to take this back and get it re-drilled? It's pretty expensive here (most places charge $30.00/hole). I'm hoping you know of a place online that sells special small outside diameter bulkheads (remember -- MUST fit through a 1" hole). <I do believe that a 1.25" drain is a 3/4" bulkhead fitting. my slightly bigger All glass aquarium one that came in a kit, was about that size. If you can, I would look into having the hole redrilled and get the people that did it wrong to redo it if possible.> Thanks bunches guys! We really appreciate your help out here in cyber-land. Angelica <Hope that helped> <Justin (Jager)> Substrate help 4/29/06 <Justin here with you.> I thought I was doing well until I spoke with a LFS looking for a new Salifert test kit. The individual asked me about my setup which I told him was as follows: 90 Gal tank Amiracle MR-300 filter Iwaki md40rlt pump angstrom 25w UV emperor aquatics series two skimmer and overflow 2 zoomed PowerSweep powerheads (no longer sweeping) <Does happen, they are rather finicky> 90lbs Walt Smith Fiji rock 70lbs of Florida crushed coral. When I advised about the crushed coral the "Sales" person acted like the world just ended and I would never have any success whatsoever. I did some research on the topic beforehand and to me it looked like an argument that has been going on since the beginning of time, live sand vs. crushed coral vs. aragonite substrates. To me it sounded like a coke vs. Pepsi debate; just a matter of personal preference. He asked why I put the coral in the system and I told him that my LFS advised that they have been using it for many years on 300+ tanks with no problems. He then stated that they have no idea what they are talking about and I should return the coral to them and buy his live sand at $37.99 per 20lb bag. Then he began to talk about how ugly crushed coral is and how my nitrites, nitrates and every other water parameter will spike and lead to my ultimate failure. Quite honesty thesis SALES person's opinion was discounted by me quite quickly because of his rude and arrogant manner in getting his point across. If I truly did the wrong thing, I have no problem in taking the coral out and replacing it with some other substrate, although I won't buy it from that man's store. <You are fine, crushed coral is a fine marine substrate. It may collect more debris that other substrates due to its larger size. You should gravel vacuum the substrate to avoid issues long term. There is only really aesthetic reasons to use different substrates. > Right now I'm cycling the tank with the rock and my ammonia is zero my nitrites are at 2ppm, nitrates 30 ppm, ph 8.3. I'm going to wait AT LEAST one more month before adding any fish and corals are not anticipated in the near or distant future. Am I doing the right thing by leaving the substrate or is this guy just trying to make a sale. By the way he also tried to sell me uncured rock for 8.00 /lb, he must really need to pay the rent. <That is a great, that you are doing this the right way, so I think you will just fine.> By the way I think your site is fantastic! <Thanks ill pass that on to Bob.> <Justin (Jager)> Please could you offer me some opinion over the use of sand in my reef aquarium? - 04/27/06 Hello WWM crew, <Good evening Bob, Jen here.> Please could you offer me some opinion over the use of sand in my reef aquarium? <Sure!> On setting up I had a purely cosmetic, (although I'm sure slightly beneficial), thin scattering of coral sand on the aquarium base. Detritus build up has meant that I have removed most of this as it seemed easier maintenance wise and coralline algae has since colonized the glass improving its bare look. I live in an area of soft water here in the UK and have recently been having buffering issues,( not helped by a faulty pH meter). <Understand that one.> Now it has been suggested by my LFS and some fish keeping friends that my chosen brand of salt is one possible contributing factor to this problem, <Could be, depends on the mix.> ( KH had dropped to 5 and pH 7.6), but use of a reef buffer has brought things back to a more healthy level,( KH 10, pH 8.2). It was also suggested that adding a 1" to 2" bed of sand would help prevent recurrence of this problem, that and a new pH meter!), but I am concerned at the detritus problem becoming an issue again. Will a deeper bed of sand and the accompanying clean up crew if purchased,( conches, sand sifting stars etc), help prevent build up of detritus? <I personally am a proponent of sand beds, and sometimes DSB in the reef set up. I would suggest that about 2 inches and then the addition of the appropriate clean up crew would help you with the issue. Remember to include many critters that will stir the bed and aerate it, also those who may consume detritus.> I'm basically after your collected insights as to whether sand is the way to go, and if so which type and how deep? <This would be personal preference. I would suggest aragonite mix approximately 2-3 inches deep; deeper if you wish.> The tank is 340 liters after displacement by the 45 kg of live rock within. Its 60 cm deep, 45 cm wide and 150 cm long. The system has been running since last June. Thank you in advance for your help. <You're very welcome, good luck with this. Jen S.> Bob Mehen, Cornwall, UK. Siphoning/Cleaning Marine Substrates - 04/26/06 I have been reading over emails for a while and I finally found what I was looking for, but not the complete answer. <<Ok>> I read that in a reef tank, if you have crushed coral then you should siphon during a water change. <<Mmm, maybe...depending on depth of the substrate (<1")>> If you have fine sand, you don't need to siphon. <<More at play here than grain size/depth but generally yes, with good water flow the finer grain sands are lees likely to accumulate detritus>> Well, we have a 72 gallon tank with 3.5 inches of an even mixture of sand and cc. <<Mixed opinions on this...should be fine>> Should we siphon and how deep? <<I wouldn't disturb the DSB, but do some reading up on deep sand beds here ( http://www.wetwebmedia.com/deepsandbeds.htm). If detritus settling in/on the substrate is of concern then "up" the flow in your tank to keep all in suspension>> A greenish/brownish layer is starting to form about halfway down and I don't know if I should disturb it. <<This is algae that is triggered by the available light coming through the tank front and likely does not extend very far in to the sand bed...nothing to worry about>> Also, since I am here, I have 50 lbs of live rock in the tank. I will be adding 50 more lbs that I have had in a separate tank for a month. Is this going to change all of the parameters in the tank initially? I just wanted to prepare myself before I see any spikes in my tests. <<If the rock is fully cured it should not be a problem though having water handy for a water change after the move (disturbing/stirring detritus) is a good idea>> Thanks, Chris <<Cheers, EricR>>

Old Sand, New SW System - 4/25/2006 Hello there again. <<Hi Heather, this is Lisa.>> I hate to be a pest but you guys have been so helpful in the past. <<Not a problem :).>> I just have a quick question. I used to have a 29 gallon saltwater tank, which I upgraded to a 55 gallon. My question is can I reuse the old sand that was in the 29 gallon? <<Sure you can.>> I bought all new sand when I set up the 55 gallon because I was having some kind of reddish/purple hair algae growing on my sand. The old sand has been sitting in the empty 29 gallon for over a year now. If I rinse it off real good can I add it to my 55 gallon? <<Yes>> Will I introduce that alga to my new set up? <<If it's still living after this time, then yes, but this is not likely.>> I'm already having a problem with Cyanobacteria and don't want to add any other problems. <<You should investigate the cause of this BGA, that way you can eliminate it.>> Should it be safe to use? I have 60lbs of live sand and you guys recommended that I go deeper. I'd hate to waste all the old sand because it was so expensive. <<Give it a good rinse in tank water to get rid of any detritus first, and you'll be fine. Do you have fish in the new tank now? You'll want to keep an eye on your water quality for some time after adding.>> Thank You <<Glad to help. Lisa.>>

Marine substrate Hi Bob/Team, <Hey Doug> My question is short & sweet. I am upgrading my 90 gallon reef tank to a 180 gallon community much to the pleasure of my "captives" & the chagrin of the wife. A bottle of wine will help soothe the latter. I am obviously going to need more sand. Do I put the new sand on top of the old or visa-versa? (typical reef setup) Thank you in advance <Yes, short and sweet. Here you can basically do what you want. You're seeding the new sand with the old sand (i.e. adding beneficial bacteria to it). So, mix it up, layer it, do what you will. I would probably suggest an even mixing. Have fun with you new large tank! Your inhabitants will love it! Jen S.> Doug

Don't Use That Sand... 4/6/06 Hi crew/Bob <Hi Joe, Jen here.> I just wanted to get some advice on an issue. A few months ago I brought back a bit of sand from a clean beach. For the past month or so, it has been stored in a few buckets which had previously stored cement and paint.<Ick> These buckets were cleaned prior to filling with the sand, although remnants of each I would think are still present. <More than likely> I would like to know if I can now use this sand in my SW tank? I will rinse thoroughly and remove all (though few) pieces of debris from the sand first, however, I am concerned whether adding the sand will have a detrimental effect. It might be worth adding that the sand looks very clean although I realize it's mostly what you can't see that does the damage! <First taking sand from even a 'clean' beach can cause problems. You have no idea the microscopic organisms that may be living in it. It, even though unlikely, could be the downfall of an entire tank. Second, the sand has been stored in buckets that have been used for something else, toxic chemicals at that - so there may be residue here. Remember, if you're using it for a tank - make sure its new and clean, even the bucket. Third the sand has been sitting for months, there could be biological breakdown here that you probably don't want to add to a tank anyway. OK? Best thing to do is buy your substrate and seed it from an established tank. Best of luck, Jen S.> Thanks in advance for your advice, Joe

Sand bed and live rock 3/27/06 Hi Crew, <<Hi Jeff, this is Lisa.>> I need advice on setting up my reef. I've just put in a 3 inch layer of Carib Sea Aragonite select. First, the bag says it never needs changing, but The Book, Conscientious Marine Aquarist, states that it will need to be changed. Yes, no, maybe? <<The substrates buffering ability will diminish over time. It will need partial replacements over time to keep this up.>> Second, when I place my live rock in, do I need to move the sand bed out from under the rock (for vacuuming) or do I place it on top of the sand? <<It's a matter of taste really, but for stability, some build the sand around, not under, the rock.>> Thanks again! Jeff <<Glad to help. Lisa.>>

"Crushing" Crushed Coral - 03/27/06 Hello, <<Howdy>> I have a 55 gallon tank with 1 1/2 inch crushed coral substrate bed. I'm in the process of getting a 75 gallon upgrade, I'm over the crushed coral look/cleaning and would like to have a DSB, which I have in my other 2 tanks that looks great and is easier to clean. Can I smash up the crushed coral into tiny pieces place this in my tank then place 1 or 2 20lb. bag of live sand on top of the smashed up crushed coral, or will the crushed coral turn into dust when I smash it? <<Hmm, you can try...seems like more trouble than its worth though.>> I'm just trying to save some money where I can. <<Then just mix/cover the crushed coral with the sand.>> Thanks. <<Regards, EricR>>

BROWN SAND - 03/24/2006 Hi Bob- <Josh here.> Added 40 lbs. of new sand one month ago. Tank is thriving with the exception of patches of brown sand on the surface. Salt water tank has been setup for five years. Can you please advise what the cause may be and how to resolve. <This information is posted on WWM. Was this a silicate based sand? Could simply be the natural progression as the new sand is colonized. Search under diatoms, blue-green algae, nuisance algae...> Thank you. <Sure. - Josh>

Grain Size For Sand-Sifters - 03/17/06 Hello.. <<Howdy>> I currently have a 90 gallon FOWLR setup with a sand bed consisting of half 1.0 - 2.0 mm and 0.1 - 1.0 mm. If I had to do all over again I would have all of the sugar-fine sand but what's done is done. <<Ok>> I have read that the larger grain is borderline inappropriate for sand sifter's like gobies and cucumbers. <<Sugar-fine serves best here in my opinion.>> (of course I asked this question to my LFS at time of purchase and they said I would have no problem adding sand-sifters with that grain size). <<Mmm...was it the only size they sold/had on hand maybe?>> My questions is, are there any sand-sifters that would be appropriate for my sand bed or does your experience say I can have the gobies and cucumbers or did I shoot myself in the foot? <<Some of the larger gobies (6"+) may handle your smaller grain sizes fine, but I prefer to provide these animals with fine-grained sand. Why not add some sugar-fine aragonite to your existing bed? The goby/Cukes will be able to sift the finer grains, while spitting out what they can't use.>> Thanks in advance and oh yeah.......awesome site! <<Regards, EricR>>

Redoing the substrate in a reef aquarium 3/15/06 Hi Bob, I have a 40 gallon reef tank which has been going for about a year. Everything seems to be fine. I recently had a service come to look at it to make sure the tank looks OK. They suggested I take out the gravel which the original people set me up with and put in sand. This makes sense, but before doing anything radical, I like to get second opinions. I have tons of lace rock which is covered with coralline & other algaes as well as some live rock I have gradually introduced. I don't want to harm any of my little creatures [ a star fish, sea urchin, a serpent star, a cucumber, snails & 2 fishes, as well as the corals], but I do want them to have the best environment. Any major problems with this? <Mmm, can definitely be... best to "culture" the new substrate... remove the sessile invertebrates, perhaps dismantle the tank to remove the old> The pros seem well read & knowledgeable & they would be doing the turn-over. Thanks, LC <This change-out can be smooth if one does a bit of planning... do rinse the new material, culture it with some of your "old water"... for a few weeks, months, before switching. Bob Fenner>

Maintenance/Operation/Substrate Cleaning? 2/26/06 I have a quick question on cleaning substrate. I use Carib sea special grade reef sand (1-1.7mm) My bed is 1/2" to 1" inch deep. With this depth it's completely aesthetic, right? <Will help with buffering, some denitrification.> So, since the bed is static, I can vacuum the whole bottom every time I do a water change. There's not any reason to do a third to half at a time at this depth because it's not performing and biological filtration when it's this shallow. <Correct, I vac mine weekly.> I know I should probably knock it down to a 1/2" everywhere. I read through all the FAQs on substrates and on marine maintenance but could find the answer I was looking for. I found numerous opinions on how deep your substrate should be, but nothing on the maintenance of a very shallow bed. My gut tells me that it's probably all right to vacuum the whole thing at once, but I'm not completely sure. <Now you are completely sure.> Thank you for time. <You're welcome. James (Salty Dog)> Jeff

Travertine As Bio Material? - 02/25/06 Hello. <<Howdy>> I got some great advice today. Thanks to everyone. <<Welcome>> Just one question that is not anywhere on the site. (Now it will be.) <<Ok>> My LFS sold me about 30lbs Travertine <<?>> for biological filtration in my sump. <<curious>> I can't find a single person with Google who uses this. <<Likely not>> This worries me. Thoughts? <<Firstly, I don't think you need worry...no harm should come to your system from this material...though that doesn't mean the possibility of introducing a contaminate is ruled out. My knowledge of Travertine is as a material used for decorative stonework in up-scale homes/buildings. Though it is a calcium carbonate/CaCO3 based material, it is fine grained/dense (polishes up nicely) and less than a good choice as a bio-media in my opinion. It likely won't hurt your tank, but I doubt it will help much either. You would be better off replacing this with ordinary live rock rubble for biological filtration.>> Thanks in advance, Christopher <<Regards, EricR>> <Mmm, having had a few rooms re-done with this material as tile recently... and read about its natural origins, am inclined to toss in my warning against its use in biological systems. Take a read on the Net here... I would NOT place this material in a biological system w/o it being tested for undesirable material/s. BobF>

Substrate questions 2/18/06 Two quick questions. My current substrate is fairly course (CaribSea Aragonite 5-10mm, 1" to 1.5" in depth) and I would like to replace it with a fine sand (Seaflor Aragonite reef sand, 1" to 1.5"), how would I go about this? <If the bed is fairly new and not supporting much life, I would just add the fine substrate and let it fill in the spaces in the coarse. If it is older and has a lot of life but not a lot of detritus, I would do the same, but slowly enough (1/4" per day) to allow the life to rise to the surface. If it is older and has a lot of detritus and not much life, I would vacuum it aggressively and then fill in with fine. Removal of the old substrate is not really necessary in my opinion.> Second, do you recommend letting your rock rest on the substrate or being suspended above it? Thanks <I am a big fan of placing pillar in the substrate (I use 3" PVC rings cut to a length slightly longer than the depth of the bed). It improves water movement, reduces dead spaces, allows critters to roam more freely and provides more surface area for biological activity. Best Regards. AdamC.>

Substrate question part 2 2/20/06 Won't the fine sand eventually fall to the bottom? My substrate is about 2.5 months old. <Yup, it will. That is exactly the idea. As it settles to the bottom, keep adding it until it covers the existing substrate. Once all of the spaces are filled with fine sand, you will have a deep fine sand bed that happens to have a lot of larger particles in it. It will function fine and will require much less sand to create the desired depth. Best Regards. AdamC.>

Substrate Question part 3 3/7/06 How deep would you go? Would 3" - 4" be sufficient? <<Sorry for the slow reply! Yes. 3-4" is ideal for deep fine sand beds. AdamC.>> Substrate Question part 4 3/9/06 Would it matter that half the bed would be very course sand - 5-10mm ? <<Doesn't matter at all. In fact, I prefer some larger grained material in a DSB to help prevent it from blowing around as much. It also benefits burrowing critters by preventing cave-ins. Best Regards. AdamC.>

WWM Question on Substrates part 5 6/18/06 The levels were checked against a calcium monitor. <<Sorry for the slow reply. I have been away from my inbox for a couple of weeks. Hmmm... I always prefer to do this the other way around. Monitors must be carefully and frequently calibrated. Using your test kit on a reference sample (known concentration) can verify that your kit and technique are good.>> My alkalinity is around 5. <<5 what?? 5 mEq/ml is a bit high. 5 dKH is quite low.>> What do you mean about keeping calcium in balance with alkalinity? <<Ideally, both Calcium and Alkalinity should be in their ideal ranges. For Calcium, this is roughly 380-400 mg/L and for Alkalinity, it is roughly 9-11 dKH (3-4 mEq/ml). If both are high or both are low (in balance), it is better than if one is out of range and the other is OK (out of balance). When Ca and Alk are out of balance, both parameters become harder to manage. Hope this helps! Best Regards, AdamC.>>

Maintenance/Operation/Substrate removal 2/18/06 I was reading some recent info on aquarium substrates that has started to make a whole lot more sense than what I have believed to be true. There seems to be an undercurrent of hobbyists that are making the radical switch to bare bottom tanks and for a very good reason. It has been explained to me that a DSB can be an unpredictable detritus trap that over time can hinder water quality and can eventually become unstable and release various chemicals into the water. I have never really liked the look of my 2-3 inch aragonite and shell gravel bed that I have in my 75 gal FOWLR. I have been taking more and more out over the course of the past 2 months. I have about 75lbs of live rock that have been in the system for over a year now and the system is filtered with a wet dry and protein skimmer combo. The other night I took out the bulk of it (Well pretty much all of the substrate) and replaced it with a thin layer (Less then a half inch) of sand. I have a Maculosus angel, yellow tang, flame hawk, Xmas wrasse, PJ cardinal and bl yel tail damsel that have been doing very well. I wanted to improve the water quality by removing the built up detritus from the past 5 years of use. Will the Live rock be enough to support the beneficial bacteria that breaks down ammonia or will my tank spike and re-cycle killing all of my fish? I know this is after the fact but I thought that I had this all worked out. <Mark, no worries. You should have enough bacteria on the rock and inside your wet/dry to handle the situation. James (Salty Dog)>

Changing/Renewing A Sand Bed - 02/14/06 Dear Mr. Fenner & Staff, <<Staffer EricR here>> I have a 90 gallon reef tank that has been up and running for about 2 1/2 years. My question is I would like to change some of my existing sand bed. The sand is starting to look dull and doesn't seem to reflect light like it once did when it was new. <<Depending on the grain size of your substrate, perhaps a Bullet Goby/Genus - Amblygobius or a Diamond Goby/Genus - Valenciennea would prove useful.>> The tank has been stable for the last year with very little problems and I fear that changing out the sand might upset the apple cart. <<Perhaps rather than replacing the sand you could add a new layer (1/2" or less) atop the existing. If your current bed is aragonite it has likely "shrunk" from dissolution anyway.>> Do you think it would be a more gentle transition if I were to change out my sand with live sand (1/2" Aragonite sand bed ) or would dry sand work just as well? <<Dry sand would be fine, though adding "live" sand will provide a "boost" to your sand bed biota.>> Thanks for all your help. I start everyday with reading the Q & A portion of your web site and have learned so much! <<Thank you for your contribution as well. Regards, EricR >>

Sand bed question - 2/11/2006 I have a 135ga. tank (been set up for fish only with crushed coral ten years) that I am converting it from FOWLR to a Reef tank. I am removing the under gravel "slowly" and planning on leaving about 1" of (from my FOWLR setup) cleaned crushed coral (to save money & keep from removing it all) and add about 2" to 3" of live sand to top. I will have a good size wet/ dry/ protein skimmer/ UV/ canister filter/ power heads for very good water flow. Do you see any major problem with having about 1" of crushed coral mixed with 2" to 3" of live sand. <No.> Will I need to clean it regularly (monthly as I have in the past)? <A good quality live sand should contain worms, microcrustaceans, etc. These guys are suppose to do the work keeping the sand churned and gobbling away at the detritus. Sand sifting stars help a great deal in this process. I don't believe I would want to use a UV with a sand bed, will kill beneficial critters along with the bad guys.> Do you think I should definitely remove all crushed coral and have at least three inches of live sand? <Choice is yours. I'd prefer all sand if I was doing this.> Would I need to clean at all? <As above and do search our site for more info on this subject. James (Salty Dog)> Kent B. Murrell

Adding/Changing Reef Substrate - 02/09/06 Hello crew. <<Howdy!>> Great site, so much info. <<Glad you like it.>> I have a 125 gallon reef which is doing well thanks in a large part to WWM. <<Excellent!>> I have taken your advice and added a 30 gallon refugium with a 6 inch DSB and a very large portion of Chaetomorpha algae. <<Ahh...good (better) times ahead!>> Also added an Aqua C skimmer and a closed loop manifold increasing my flow by about 700 gallons per hour. Also have removed all bio balls from the wet/dry. <<You've been busy...>> Needless to say my system has never looked better and my nitrates have fallen to < 2.5 PPM (Salifert). <> My thoughts are leaning towards possibly changing or adding to the substrate in the main display. <<Ok>> I have about 3 to 4 inches of crushed coral and sand mixture at this time. That was before WWM and via the advice of my LFS. I would like to add fine sand to the main display. Is it Ok to add to the existing mix or do I need to remove it and start over? This would not be the easiest thing to do. <<Adding to existing will be fine...is what I would do.>> I was thinking of vacuuming the crushed coral very thoroughly in small areas prior to adding the sand. This would be done in stages and not all at once. Does this sound possible? <<Sure>> Sand looks so much better and I understand is much easier to maintain. Looking to add a couple of inches as stated. <<The fine grained sand will work its way to the bottom and need "topping up" eventually.>> Thanks for your advice. You site is awesome <<Thank you for contributing. Regards, EricR>>

Good Sand? - 02/07/06 I purchased play sand from Wal-Mart that is from Thomasville, Pa. It's very white and I would like to know if this will be safe for my reef tank. <<Safe?...probably...beneficial?...maybe not.>> I have gotten differing opinions most saying if it does not say tropical play sand don't use. <<Mmm, not necessarily.>> One individual I spoke to was saying that if I put it in some vinegar it should dissolve, tried it and most of it did, can you help? <<If the sand dissolved in vinegar it is likely carbonate based and quite suitable for your reef tank. EricR>>

Cyano/control, adding sand and an Anthias 2/2/06 Hi crew! I love your site and visit it daily... just to make sure there is nothing I have missed. Keep up the great work! I am currently in the need of some advice, however. Tank specs as follows: 50 gallon, 20H x 18W x 48L 65lbs live rock 4 x 65 watt PC (two actinics, two 10K daylight) Ammonia/nitrite - 0 Nitrate - 10ppm PH - 8.3 at night SPG - 1.025 Calcium - 410 Alk - 4 MEQ (should this be higher?) <Mmm, no. This is right about right: http://www.advancedaquarist.com/issues/feb2002/chemistry.htm> This tank is a mini reef that has been up and running for 3 years. Mostly soft corals...leathers, mushrooms, zoos, button polyps, xenia, star polyps, and a couple of impulse LPS...one hammer and one open brain. The livestock is well and healthy...with most of the inhabitants doubling within the past year. The tank had been fine for the first 2 years it was set up...went through the initial diatom bloom that went away as the tank settled....and I never saw any other algal blooms....until now. lol I have what looks to be hair algae, but it comes off in clumps and feels slimy. I'm still confused as to what kind it is, and I've searched pics posted on here and still cannot ID it. The guy at the LFS told me it was probably due to high phosphates from my tap water. So I bought a tap water filter (all really I can afford at the moment) and some Ultra life Slime remover (ever heard of this?). <... yes, and not advised> I added the slime remover for a day, performed a 10gal water change in which I proceeded to scrub the algae off MOST of the live rock. I thought I had gotten it all, things were well in the world. However a few weeks ago....I upgraded my lighting to what is stated above. It used to be only 2 65 watt 50/50 PCs. And now the algae is back with a vengeance!! <Yes... just "recycled" the nutrients...> I'm assuming that I'm still getting phosphates in my water, and the light fueled another bloom? <In part, likely> I currently have no space for a sump or refugium, and run a hang on back Aqua C Remora and a millennium filter in which the media has been replaced with Chemi pure and PolyFilter. I do 5 gallon weekly changes...and I really have no qualms over brushing the algae off the rock again. I kind of enjoy killing off the buggers. I have also read that live rock loses it's buffering capacity and some of it should be replaced periodically? <Yes... posted on WWM> I've had the same live rock for 3 years....would this be a smart move for me? <Yes> I'm also thinking of adding more sand to my display, but have read conflicting ways on how to do it. I've read that you should do half first, and once that establishes, the other half. <One approach... again, posted> I read somewhere else that you should not cover the existing layer of sand. Since I would have to do it with my livestock STILL in the tank....would this be feasible, or just leave the 1inch I currently have alone? Well...I'm not done yet!! I have my heart set on a Starburst Anthias. Current fish stock includes, 2 black clowns who are so busy trying to decide who will be the male/female that they take no interest in anyone else in the tank. One canary wrasse who is wrapped up in its own reflection, one bicolor blenny who on occasion munches on the aforementioned algae, and one rusty angel who is king or queen of the tank. There lies my concern. This fish hasn't bullied any of the other tank mates....but it is pretty boisterous come feeding time. I was thinking I could add the Anthias with about 3 Chromis to act as dither fish, in case the angel decides he wants to reign supreme. I haven't added any fish in a year....so I'm a tad concerned before I spend $40 on this Anthias. ::sigh:: But the angel is my favorite. Any thoughts or suggestions? <Will likely mix, though hide in this setting> I also have my heart set on a clam...and from what I've read, the lowest light requiring species is the T. squamosa. Would I be able to maintain one with my current light set up, once the algae problem has been resolved? <Likely, yes> That's another reason why I wanted to add more sand, I read they prefer the sandy bottom of the tank. Also...would I need to supply phytoplankton? <... I would> Again I hear conflicting info....yes they need it, no the light is all they need. Any help you could provide would be greatly appreciated. Sorry this has been so long and excruciating....I look forward to your reply. Thanks, Karina <Take your time... and enjoy the process/es... Bob Fenner>

Australian Gold Sand 1/25/06 Hello, I am sorry to bother you with a somewhat silly question but I am beginning a reef tank and I am trying to research everything. I did not see anything on your site regarding my question. I am trying to learn all about LS, what is troubling is how "live" is not truly "live" and so on. I have found a beautiful sand by Nature's Ocean called Australian Gold. It is not live, but I have a friend with an established reef tank who could give me a pound or so of her sand. I have only seen it on one site and no references <references as to what?> at all anywhere else. Has anyone heard of it? Is it even legally allowed to be sold or is this fishy? <I'm sure it is legal or they wouldn't be selling it.> It is so beautiful that I question never seeing it for sale or talked about. Again, I did try the forums but I didn't know how to post a question there. Thanks for the trouble. <Why don't you go to their web site and contact them. www.naturesocean.com James (Salty Dog)> Jill

Marine Substrate anaerobic area 1/20/06 To the WWM Crew <FlÃ¡vio> Last night I noticed, over the substrate of my 6 years, 450 litres reef tank, a small white zone, more or less 5 cm diameter, 1 cm height, that look like cotton waving with the water turbulence. The substrate is a very, very fine soft yellow sand that was put in the tank one month ago. The white stuff has a "bad" look, so I decide to siphon it. When in procedure I noticed that the sand under the stuff as a black color and from the recipient a very bad smell is exhaling. I have stopped the siphoning immediately, because the problem is hydrogen sulfur. <Yes, likely so... I would vacuum all out, rinse, wash it and let it air dry... possibly return> I must remove all the sand but I think the better way is to do that very slowly in order to liberate as less gas as possible. Maybe 10 cm2 each day? More? Can you give me some ideas ? The total substrate thickness is about 2 cm. It is a thin one but I found now that the grain size is too small. Tank you very much for your help is this dangerous situation. The SPS, LPSs and fishes are ok, for now. FlÃ¡vio

H2S Substrate follow-up 1/20/06 To Mr. Bob Fenner <FlÃ¡vio> Thank you very much for your fast help and advice about the "sulfurous zones" in the substrate of my tank. I also noticed that under the dark sand there is some decaying coralline algae and may be some kind of other living tissue, may be sponges, that grew in the pre existing bare bottom. Tomorrow I will vacuum it all, because today it's not possible for me. I have in a 5 kg plastic bag a new sand, the name of which is Reef Base - Porous Reef Spheres - Natural Aragonite Mixture, of Red Sea Company. Do you know this product? <Somewhat, yes> It looks nice and has a good texture and size. The alkalinity of my tank water is 11 dKH, calcium about 350 and it works with a calcium reactor. I thank you very much once more for your help and kindness. FlÃ¡vio <You're welcome my friend. Bob Fenner> Re: Changing substrate 1/17/06 Thanks for the link to Anthony's article. The only question not answered there is whether I need to remove all my coarse aragonite before adding the fine aragonite or can I remove part of it and add the fine on top of the coarse?<you probably should remove the coarse aragonite because the fine aragonite will seep through and wind up at the bottom. good luck, IanB> Thanks Ken Bubble/gas Problem 1/16/06 To : The Gods of the Fishkeeping hobby.<No gods, guys & gals> Dear God, I have a marine tank for over a year and recently I have notice bubbles emanating from the coral sand based gravel bottom. I do not have a UG hence very baffled. Need help Lord. <Say two "Our Fathers" and two "Hail Marys" and all will be well my friend.:) If your coral sand base is much over 1 1/2 deep you are probably looking at hydrogen sulphide gas erupting from the bed, not a good thing. When you do your weekly water change do you vacuum the bed? Needs to be done unless you have a lot of critters in the sand been churning things up. James (Salty Dog)>

Re: Sudden unexplained loss of fish 1/17/06 Thank you so much for your quick response. <You're welcome> After reading your response I was able to do some additional research into hydrogen sulfide gas emissions and am pretty sure you nailed it. I was happy to take your advise and reduce the depth of the sand bed in my tank. So far all of the fish I removed to quarantine are doing well and I will be ready to start putting them back in the main tank as soon as it cycles for a few days. Just wanted to thank you for your insight on this and the work you all do to get this information out there for everyone. You are much appreciated! <Thank you Kimberly. James (Salty Dog)> Kimberly Kennedy

LS and white sand mix 01-11-06 Hi WWM, <AngeloM3> Just about to start the cycling for my 55gal tank. I have 40lbs of LS and 20lbs of white sand, with about 30lbs of dead LR going in for the cycling. After its done the cycle I will add about 20lbs of Cured LR. <Do not wait for the cycle to end to add your live rock or your will start another cycle.> I do plan on getting 2 Lawnmower Blennies and various inverts (plus about 4 fish and 1 anemone). Couple of questions about cycling and the sand layers........... Since I'll have the blennies and inverts that will be sifting the sand, how should I layer the sand? White sand on the bottom with LS on top? Or visa versa? <It doesn't matter as it will not stay in layers.> Also a grate was included with my tank that covers the entire bottom of my tank (but is removable) what is this for and do I need it? <Get rid of it. It will hinder your deep sandbed critter from doing their job.> During the cycling period.... how often and what percentage of water should I be changing? <<Depends on measured water quality... RMF>> <None. Good luck and make sure to use this cycling time to research your future animals. Travis> Thanks for your help -AngeloM3

55 gal reef tank in Bahamas 1/10/06 Hi, <Hello> I have been reading your site and realize I must be extremely lucky. I live on the water in the Bahamas and catch all my critters in the back yard in knee deep water. <How nice> I have a 55 gal tank with sand and rock that we picked up. It has been up and going for around 1 1/2 years. I have a bunch of crabs, urchins, Brittlestars, a sand sifting sea star, some shrimp , anemones and some fish ( snapper, parrotfish, wrasses, beau Gregorys). I change the water , from the back yard, every couple weeks. Usually around 1/3 to half of it. I feed them Prime Reef and some fresh fish chunks. <Sounds good> Everyone seems to be happy. I am sorry I cant use the technical terms I just got online here and am learning a lot but I have just been winging it. <As long as you're understood... the medium is the message> My question is should I add or change some of the sand on the bottom? Or just leave it alone. Thank you so much .Michelle <And you for writing, sharing. Bob Fenner>

Sandbed Selection, Not Always A Personal Choice - 01/09/2006 Good evening, <Hi Mike.> I am in the process of setting up my first marine/reef aquarium and I need some professional advice. <I'll see what I can do.> I have a 75 gallon tank with 100lbs of live rock, AquaC Urchin Pro and an in-sump refugium. <Good start.> I am interested in keeping a goby, goby/shrimp pair, or perhaps some other type of burrowing fish like some of the Jawfish. <Ok.> However I'm not sure that I completely understand the sandbed requirements for keeping burrowing fish. I am not particularly interested in NNR (DSB) in the main tank and the only reason I want to use sand is for aesthetics and as a habitat for these fish. Do you have any suggestions for a beginner? Thank you for a response and for the wonderful service you provide. -Mike <Gladly. - Josh>

Changing substrate - 01/09/2006 I have had my 55 gal tank set up for about 2 years. It has a bed of coarse aragonite (.5 to 1 mm), varying from 2 to 4 inches in depth. In reading the info here on WWM I'm thinking that it's time to replace some of the aragonite, and it looks like "state of the art" is a DSB of sugar-fine aragonite.
<sounds like a good idea!> So, do I need to totally remove the more granular substrate before adding the finer variety, or can I remove the top half of what I have and add the finer substrate over the top? What should the total bed depth be?<all of your questions can be found here http://www.wetwebmedia.com/deepsandbeds.htm> I expect that even after I aggressively rinse the new aragonite there will be an introduction of fines into the tank. Will that bother the fish (one Perc, one pajama cardinal, one purple Firefish), the Kenya tree, mushroom, and Crocea?<probably not> I have a QT that I could relocate them to if need be, until the "dust settles".<the dust should not bother the fish too much but make sure it does not settle inside the clam, good luck, and read the info in the link provided! IanB> Thanks! Ken Baker

Substrate Change and Water Quality 1/8/06 Hi Crew, <Hello Ernie.> Just found your site not long ago and would like to say thanks for all the great information in your pages. <Glad you are learning form and enjoying it.> Wished I had found it along time ago. <Me too.> I just took out 3 inches of crushed coral off the top of 3 inches of .5 to 1 mm aragonite sand. I replaced the crushed coral with 3 inches of the same .5 to 1 mm aragonite sand. <Cool.> I kept all of my live rock submerged in rubber maid container during this process and used the same water that was in my tank originally to refill. Plus or minus ten gallons of aged water made up aerated, and ph and salt balanced. Question is will my tank recycle after this process. <It shouldn't go through a large cycling process again, no. However the disturbing of so much substrate and the removing or disturbing of bacterial colonies may cause some water quality issues as far as nutrients. I would continue to test the water daily for at least a week or two after the switch and do a water change if necessary.> My fish are currently moved to another tank but it is really crowed and I would like to get them back home. Thanks a lot. <Just test and check the stability, if everything checks out, you're good to go.> Ernie in Kansas <Adam J in SoCal.>

Hydrogen Sulfide - 01/01/2006 Happy new year to you all, <And to you Will.> This weekend I had the pleasure of stripping down my 60 (UK) gal marine tank for the 2nd time, what a way to end the year but with a nice slow leak...? Anyway all the rocks corals fish etc. are in a nice spare tank set up with heater, filter, skimmer, and sand is in a vat with water and a powerhead. However my sandbed seems to have been producing hydrogen sulfide instead of nitrogen, kind of lucky the tank leaked in retrospect. The sandbed is about 4 inches deep I should imagine, maybe a little under, I have a bout 240lph of flow through the tank <excluding skimmer>. What's causing the hydrogen sulphide? Bed too shallow? Not enough flow? Wrong bacteria proliferating? <Anaerobiosis, organic build up. Flow must be leaving dead areas.> And other than the smell what effects does this substance have? Suppressed pH or is it actually toxic? <Hmm....Being from lack of oxygen, the pH would be depressed, could have a random "die off" of all livestock.> FWIW soon I shall be upgrading from a Prizm skimmer to a v2skim 400, will this help problems, the Prizm never really does much <other than irritate the family with it's gurgling and bubbling> <Will likely help as will better flow. Good surface turbulence will help gas exchange.> Thank you in advance, Will <You're welcome. - Josh.> Re: Hydrogen Sulfide - 01/02/2006 Thank you, <You're welcome Will.> With regards to flow I shall put the 2 800lph pumps at each end and I have a 900lph which I shall put in the middle, I was thinking of placing in the middle of the tank with a powerhead aiming through the rocks, would this be a good idea? <Hmm...You've kind of lost me here. Are these new pumps? These weren't listed earlier. At any rate, I would direct the two 800 pumps slightly downward from opposite ends (so they converge in the middle. The 900, I would mount high on either side of the back wall angled slightly upward and across the tank diagonally (enough to push the surface up about a 1/2 inch). The current will form a slight arch, coming down in random locations because of the surface turbulence.> Should I point the two 800's at the front glass or just through the tank aimed slightly at the surface? Thank you again Will <My pleasure. - Josh>

New Tank and Nerves'¦ 12/24/05 Hi, <Hello.> I have a 55 gallon saltwater tank that was recently set-up (a little over 48 hours now). <A very new tank.> It was extremely cloudy when first set-up but it did seem to clear up a bit as time went on but not 100%. <This being a VERY new set-up this is quite normal, no worries.> Today I bought a small amount of live rock to add. <Good.> When I did, I stirred up the sand a bit (not on purpose) and the tank is now very, very cloudy. <Normal.> I have a wet/dry filter and just now noticed that I have a thin residue of sand dust all in my sump and on the filter pads. I washed the pads out but is the residue in the sump anything to worry about? <As long as you have baffles in the sump protecting your return pump so that debris does not get into it, no worries, just use a siphon tube to get the sand/detritus off of the bottom of your sump.> Also any advice and recommendations you have (other than waiting it out) on helping the clarity of the tank would be most helpful. <Yes as you allude to your best tool right now is patience.> Thanks and happy holidays! <To you too, Adam J.>

Stocking and Sand for a 29 Gal. - 12/17/2005 Hey guys first time question, long time reader. First up thank you for running such a great site. <Glad that you enjoy it, though we'd probably be lost without the help from the ladies!> Okay I have 29 gallon with a magnum H.O.T filter, 20watt NO lighting, with 24lbs of live rock and about 20lbs of aragonite live sand. I've had the tank up for about two months now and just ordered the Orbit Lunar Lights PC (130watt), MaxiJet 1200, and the Bak Pak 2. In my tank I have 2 Yellowtail Damsels, a large Green Brittle Star (about the size of a computer mouse) that hitched a ride on some liverock, <I'd recommend removing this. Well known for ambushing fishes at night.> a Feather Duster and 2 Peppermint Shrimp. Water checks out fine as well, I do a 5 gallon water change a week because of the lack of a skimmer. <Good but better to have the skimmer.> First question is I plan on getting rid of the Damsels for 2 Percula Clowns, a Flame Angel, <The Flame Angel needs more room.> a Sixline wrasse <May not work out either.> and 2 Skunk Cleaner Shrimp, not at all the same time of course. Is this a fair load of livestock or overkill? <Way over.> For corals I would like to do some striped mushrooms, button polyps, and xenia, I hope my new light would be powerful enough for these. <Should be fine but be careful mixing these in a small tank.> My last question is I would like to add more sand to my tank to create a deeper sand bed. Can I use the same live sand about 20lbs or would that cause an ammonia spike in my tank? <Can use the same, be careful not to bury the existing bed. You'll have to add small amounts at a time, in sections. Move a portion, add sand smooth back over.> Thanks <You're welcome. - Josh>

Sand Bed Questions marine vs. planted freshwater 12/10/05 Good afternoon (I hope), <Yes I'm doing quite good, hope you are as well, Adam J with you.> Last night I helped a friend setup a planted tank. We laid heated cables (root therm) under the substrate to cause a gentle circulation through the substrate so there are no dead spots. From my understanding this is a pretty common practice in high end planted tanks. <Yes.> My question, is there a practical application for this in the marine aquarium? <Usually not necessary in marine tanks nor is it very beneficial, in fact it would be a bad idea for those who plan to utilize a Deep Sand Bed, would disrupt various microfauna and bacteria populations.> The concept should work the same shouldn't it. <Not exactly.> We were basically following a book when we were doing this "Aquarium Plants: The Practical Guide" by Pablo Tepoot. When we did the substrate we laid a fine layer of gravel (a bit bigger than sand), and then a coarse layer, with a layer of laterite (sp.) <<laterite>> in the fine layer. The book explains that the fine layer is the anaerobic layer, and the coarse layer is the aerobic layer. Is this also applicable in a marine aquarium? <Research these two phrases via WWM (Plenum) and (Deep Sand Bed), I think this is what you are looking for.> Thanks, Daniel <Welcome, Adam J.>

Used gravel - Let's Call it "Pre-owned"! 12/03/05 I have a neighbor who failed with his 180g reef (two floods-ruined home theater in room below tank, fortunately still married though). He then tried fish only for a while, then finally converted to fresh water. He's offered to give me 160lbs aragonite gravel which was in the tank through all of the above (including FW with a Pleco and some goldfish for ~1 yr). He never used any meds, copper or otherwise, and says disease wasn't a problem. Would you be nervous using the aragonite in a new reef? Thanks, Neil <Yes Neil, wives can become very nasty when situations like that occur. To answer your question, no, I would feel comfortable using it, just rinse portions of it at a time in a bucket. James (Salty Dog)>

Aragonite, but Which Adam..?? 11/30/05 Hey Adam <Hello?> I would like your opinion on aragonite as a substrate as I've never bothered to incorporate a substrate, I have no idea which one to purchase. <Well first you need to decide why you want substrate. There could be a number of reasons to incorporate substrates in marine aquaria; aesthetics, to enjoy the benefits of a Deep Sand Bed or creating a certain type of biotope or living environment (i.e. resting spot for wrasses). As for aragonite it is calcium based making it useful for its buffering effects in the marine tank. The problem with it is that most hobbyists choose a brand that is too coarse and thus it becomes a nutrient/detritus trap. I would attempt to find material that is as fine as possible. Another thing to consider is the flow rates within the tank, tanks such as high flow shallow water biotopes can make sand beds quite impractical.> Thanks. <Adam J.>

Sand Beds And Hydrogen Sulfide? - 11/28/05 Hello WWM: <<Hello>> I loved Mr. Fenner's book, The Conscientious Marine Aquarist; it saved a few fish lives, I am sure. <<Tis a very good read.>> I trust his opinion and hope he or the crew can help me out with a potential catastrophe. <> As I am sure you have heard many times before from other newbies, I got some bad advice from a local, large pet supplies dealer when I set up my first marine tank this past June: <<Nothing beats doing your own homework my friend.>> 55 gallon FOWLR, wet/dry with bioballs, Pro Clear Aquatics skimmer, Emperor power filter, a coral beauty, 3 yellow tail damsels, two tank raised Amphiprion ocellaris clowns, a peppermint shrimp, a couple of snails and a tiny crab (hitchhiker in live rock). <<Glad to see you haven't overstocked.>> When I set up the tank, this pet store employee sold me live sand and coral gravel and said to place the sand on top of the gravel and now I have a 1.5 inch base of sand on top of 1.5 inches of gravel. <<Will eventually mix...>> I now believe this advice was wrong after reading through your site as it is a detritus trap and possible cause of hydrogen sulfide. <<Maybe...maybe not...>> I recently lost 10 snails (mostly turbo) and a peppermint shrimp to unknown causes but believe that hydrogen sulfide gas might be the problem. <<What is this based upon, did you smell hydrogen sulfide, or are you just reacting to what you have read? Snails die all the time for many reasons (might even be that hitchhiker crab). In most instances, fears of hydrogen sulfide poisoning are overrated in my opinion. Even when present, this gas exits most systems (having good water movement) before doing anything more than causing the aquarist to wrinkle his/her nose.>> I do remember I lost the shrimp a few days after an intensive vacuuming of his favorite spot around a live rock. Although probably unrelated, I also lost a Amphiprion ocellaris clown to a possible bacterial infection (?) as it had a round, whitish gray sore near its tail and it died a few days after this sore appeared. I was doing light vacuuming of the top Â½ inch of sand for the first two months, then I read on the internet somewhere that you do not need to vacuum a sand bed <<agreed>> so I did not vacuum for the next two months. However, after reading a FAQ or an article on your site, I again started light vacuuming last month. I have had the tank 5 months and did not vacuum for 2 to 3 months. <<Differing opinions abound...but I can tell you I have had sand beds (of varying depth) for many years and I don't vacuum.>> I noticed some dark areas in the substrate but no fishy smell yet. <<Probably alga...tis natural and most often desirable.>> After reading through your site yesterday, I have decided to go with one inch or less of substrate and therefore need to remove some of the substrate in my tank. <<I'm a DSB guy...but this method is fine too.>> How can I do so without releasing hydrogen sulfide gas, if any, upsetting the water quality (0 ammonia, 0 nitrite, 40 nitrate <<This needs to come down...20 or less...>> 8.2 pH, 1.24 SG), and protecting my livestock? Can I just remove the gravel and/or sand or must I remove the fish and inverts first and then remove the substrate? <<No need to remove the fish/inverts. Likely little to be concerned with, but you can simply siphon out a 1/2 inch of substrate every few days until you get down to that sub-inch depth.>> Can I leave the last one inch layer of coral gravel with some fine sand mixed in as some of the sand has settled down through the gravel or should I do a complete change of substrate? Can you recommend anything? <<Should be fine to utilize what is already in the tank.>> Please help, I do not want to lose any more lives. I am really worried about wiping out the whole tank from this gas. I am totally confused from all of the different opinions on the web, fish dealers, and in books and magazines <<and on WWM!>> I am ready to call it quits! <<No worries mate...not all as bad as you may think...all should be fine.>> With sincere appreciation, Geraldine <<Regards, EricR>> PS: A month ago, I went back to the same large pet supplies dealer and was sold Nature's Ocean Pacific Coral Gravel, 4-8 mm, enough to provide about 2 to 2.5 inches (?) of a base. I believe this is too deep for this gravel and it is very dusty, has tiny grains of sand mixed with large pebbles, and appears cement-like when wet! It just didn't look and feel right so I am returning it; I don't even want to use it for a 1 inch base. <<Mmm...if you do decide to replace all...I recommend something in the 2-5 mm (mixture) range for a 1" bed. EricR>>

Re: Sand Beds And Hydrogen Sulfide? - 11/29/05 Eric R.- Thank you so much for responding so quickly. <<You are welcome Geraldine>> I just finished reading through all the FAQs on the WWM site regarding hydrogen sulfide and thought I might be over-reacting. <<Kinda what I thought too...no worries...>> I then checked my email and was relieved to find a response from you which further convinced me that I am probably over-reacting. Phew! Now I can fall asleep tonight with the knowledge that there is hope for me and my fish after all. <<Hee! Glad to hear you/your fish will be sticking around.>> Everyone on my Xmas list is getting WWM T-shirts this year! <<Cool!>> Just one more observation: I thought DSB's were mainly for reef tanks and not FOWLR tanks. <<Not at all...the methodology can be applied/beneficial to both.>> Happy Holidays to everyone at WWM. I don't now what I'd do without you.... <<And to you in kind...>> Geraldine Newton, MA <<Regards, EricR in Columbia, SC>>

Home Depot Sand - 11/25/05 The white sand at home depot has changed from "Southdown" to "Gulf Beach" sand distributed out of state of Illinois. Knowing that some products contain silica does anyone know if this new product is marine reef tank safe? <<Drop a pinch in to some white vinegar...if it bubbles/dissolves you're golden. EricR>>

Mixing Substrates - 11/20/05 Hello WWM Crew! <<Hello Aly! EricR here>> I'm finally converting my 7-year-old 46 bow front FOWLR to reef (I know, what took me so long!) <<Mmm...nuttin wrong with fish...>> and I've got the ill-talked about CC substrate in there right now. <<Not all bad...much to do with grain size/depth.>> I've been reading up on substrate for the past week here on WWM and I'm going to make the switch to a SSB. <<I'm a DSB kinda guy...but this is fine too.>> I'm going to take out 1/4 of the CC at a time and replace that section with the sand over the next month until all is complete. <<Alrighty>> So just a few questions I need a little clarification on, if you don't mind. <> Sand Type- I think I'm going to go for the Aragamax sugar-sized sand mixed with a bigger grain. <<You can do this, but not necessary. Much more simple to just pick/choose a grain size and proceed...>> I like the look of the Bermuda Pink (2.0 - 5.5 mm) but I've seen it described as a mini CC substrate. Fiji Pink Reef Sand (0.5 - 1.5 mm), Flamingo Reef Sand (1.0 - 2.0 mm) and Grand Bahama Biome (0.1 - 2.0 mm) are also on my shortlist but I have no idea what would look or work best mixed with the sugar sized. <<Mix or not...my choices would be the Fiji Pink or the Flamingo Reef Sand. Best combination of grain size/variation in my opinion>> I'm running all of that info off the Carib-Sea page: http://www.carib-sea.com/pages/prod.../aragonite.html What would your preference be to mix with the sugar size? <<As stated...but without mixing in the SS.>> Mix Ratio- What ratio would you mix the sand? I used an online sand calculator that says my tank will need 23 lbs. to make a 1" bed. A 1 1/2" bed would come to the bottom of the black strip on my tank but I read that would be a bad depth (just in case, I would need 34 lbs. of sand for the 1 1/2" bed). <<For the SSB I would use 1" depth or less. If you decide to mix with a sugar-fine substrate then I recommend no more than 30% of the fine stuff.>> Rock Slide- With the transfer to sand, I'm worried about a rock slide driving straight through a 1" sand bed and cracking the bottom. <<Of little concern...think about the folks who don't even use a substrate (bare-bottom).>> I had read about eggcrate being a possibility from a LFS. Will that help cushion the blow if there's a rock slide? <<It could...but the 1" substrate will do just fine.>> I guess I've come to rely on the cushion of the CC, which sounds silly now that I think about it! <<Hee!>> Thanks in advance for your help! -Aly <<Welcome, EricR>>

Re: Mud/DSB/Refugium 11/16/05 Thanks for the response. Because of the bulk (all LR at once) I don't have and don't really want to buy a whole new setup just to cure it. Though, I've never experienced the smell. Is it likely to cause my wife to move out until it is over? <Heeee! I hope not... might be a good to better idea to "do in batches"... that is, a box at a time, adding another in monthly or so increments... less smelly. Or to opt (call the supplier re) for "better" or so-called "pre-cured" rock (will need to be cured nonetheless... just "on average" less so, smelly> In which case it may behoove me to foot the expense and do it in the garage. <Oh yes... can be done in most any non-reactive containers... e.g. new plastic trash cans...> I am expecting to set up a smaller QT tank in the future for incremental additions, but it certainly will not handle the initial LR load. A couple of FUP questions, if you don't mind: 1) I've read much about using pipe etc to prop LR off LS. Is this to allow a water space between the bottom of the LR and the substrate, or other? <Mostly this function, yes... also helps stabilize the mass on top, allows for somewhat easier maintenance> If other, is there any reason "dead" coral couldn't be buried in the DSB and used as a support to the LR above? <Mmm, nope... just would miss out on the above benefits> 2) As many have suggested, I have added much of the Aragamax without rinsing first. <Ughhhh! A mess> The first few times I did this, after some time the water did clear. Now, however, I have had a perpetual cloudiness for several days. Recommend I just wait, with/without circulation, or buy/borrow a diatom filter, or is there a flocculant that is safe for this purpose? <Borrow/rent the Diatom... the cheapest, fastest fix> Thanks again for your help, and thanks for "Reef Invertebrates". Great book, I am waiting with anticipation for the next. <Unfortunately the series is "dead in the water" for now... Bob Fenner>

Sand question 11/9/05 I have a 10 gallon SW with 1.5" sand, fish and mushrooms. It is now about 30 months old. I noticed a patch of sand (about 4x4 inches) that looks like a mound. First I thought it was my Gramma excavating which he does every once and a while but I ruled that out. The mound started coming to a point. I decided to explore it and I dug into it. The sand seems to stick together as if it were magnets and it feels clumpy to the touch. <Good description> Water parameters are stable; ammonia 0, nitrate 0 and even nitrites 0 (since I added some Chaeto). I do not clean the sand since I do not see a need for it. I never see any debris on it so I assume my critters and worms are taking care of everything. Is this anything to be concerned about? <Mmm, not much... likely this is some species of worm or mollusk at work/living... with such small systems aging, it is a good idea to "shake up" the chemical/physical make-up periodically... add, replace a good part (a few tens of percent) of rock, substrate... Bob Fenner>

Question Regarding Hawaii and Sand 11/3/05 I plan on collecting some live sand from Oahu for my tank, in accordance with Hawaii law of course (1 gallon per person per day). Thankfully, most of the sand here is of the right composition, with lots of calcium, <Yes... am sure you've been to the Waikiki aquarium down at Kapiolani... seen the "saltwater wells" they've used for decades... very good water with little work> but I am not sure where to find sand fine enough to establish a good, nitrogen-cycling deep sand bed. <Is most everywhere> I thought I would try Bob on this, since he has some familiarity with Hawaii. I went to Lanikai last weekend, and the beach sand is fantastic, however the live sand in the tidal zone is much more coarse. Any suggestions? Also, after using your website for several weeks, I finally bought your book yesterday. It will be a great reference to keep around. Thanks. Doug Cook <A hu'i ho! Bob Fenner>

Self-Collected Substrate Material? 11/1/05 Hi There, <Hi! Scott F. with you today!> I live on the West Coast of Ireland and have access to Irelands only coral beach. The sand is composed of fragments of broken coral from about 3-10mm long. Would it be safe to use this as a substrate? The beach, water is pristine. Would the fact that it is coming from a cold water environment to a tropical tank reduce the possibility of introducing pathogens? The tank is a new tank and will have no fish in it for at least two months. Thanks for your time, David <Well, David, I am always concerned about the introduction of pathogens and/or pollution from wild collected substrates, but it sounds like you may be looking at a good product. Be aware, however, that fairly coarse (and I'd classify this material as "coarse") substrates do require a lot of attention to husbandry, as they tend to trap detritus over time. I'm not 100% certain that the temperate/tropical issue would assure you of a potentially disease-free substrate. I am, however, more concerned about the ecological impact of collecting from beach sources. Many communities have strict laws about collecting wild materials from their beaches and other ecosystems. Do check with local authorities first. If they give you the "green light", then it's worth a shot to use this material. In the end, your 2 month "fallow" period will probably help reduce the possibility of introduced pathogens. I'd still clean and rinse the material thoroughly before use. Best of luck! Regards, Scott F.>

Freshwater to Marine Conversion: Substrate 10/27/05 Hi, I'm pretty new to the hobby. <Hello Andy and welcome to the addiction, I mean Marine hobby.> I have kept some cichlid for a while and want to try my hand on coral and anemone. <Okay be sure to thoroughly research these animals beforehand, reef tanks are not a casual endeavor. The anemone especially is quite challenging and has specific needs'¦.best left in the ocean or to veteran aquarists.> I need to know if I can use my current crush coral as a substrate for my saltwater tank? <Short answer is yes. However depending on the grain size you may want to reconsider, if it is a large grain size I would not use it as it will trap detritus and cause nutrient problems. Also look into adding more sand or crushed coral to enjoy the benefits of a Deep Sand Bed. At the least I would remove the crushed coral and thoroughly rinse and dry it before use in the marine tank.> Thank you very much for the advise. Andy <You are welcome, Adam J.>

Cloudy water 10/25/05 Hey, I mixed salt in my tank a day ago and the water is still very cloudy. There is also white stuff floating all over the top. I had aragonite in there before I mixed the salt and it was very cloudy from that once I poured the water in. Is it the salt or the aragonite that is making it so cloudy? I have powerheads running and that's it. Is there anything else I can do? Or is this normal and I need to just wait for it to clear up? <If this is new aragonite and you didn't pre-wash, then yes, its from the aragonite. James (Salty Dog)>

Re: cloudy water 10/25/05 Yes it is new. I didn't think I had to wash it. Do I need to start over or will it clear up? <Don't have to start over but it will take a while for it to clear up. Might want to check the ph of the water. Sometimes this can cause low ph readings. James (Salty Dog)> <<Or, you can buy, beg, borrow or steal a Magnum HOT filter fitted with the diatom filter - used for "polishing" the water - to remove the fine particulates that are causing the cloudiness. MH>>

Sand From the Local (Non-Tropical) Beach, Not a good Idea 10/6/05 Hi guys, and gals. <Hello, Adam with you this evening.> I have a question that could be useful for some people. <Probably that's why we post them in the FAQ's.> I live on Myrtle Beach, sc. And I can't find the good homeland as they only have the "sackrete" brand of play sand. and my trip to a few Lowe's in the area didn't produce any results either. So my question is: can I collect the substrate off the beach? <Not a good idea.> I'm sure your gonna say that the substrates from the beach has parasites and pollutants in it. and my response would be a scenario were I would boil the substrate somehow to disinfect it. And kill the parasites, hopefully. <You're right if pollutants and parasites were the only thing to be worried about it would be very easy to sterilize and cure the sand. But you didn't think it was going to be that easy did you? The problem that we face is that sand is not sand. The sand you would find on a tropical beach is calcium based, the remains of ancient corals and other calcium based organism remains. The sand you will fin on your local beach is silicate based. At the least it will give way to uncontrollable diatom algae growth in your tank.> And is collecting 200 + lbs. of sand from the beach illegal? <Varies from localities, consult you local authorities before collection.> thanks for the help. <No problem, and not to nit-pick but please capitalize and punctuate sentences as this will end up in the FAQ's for others to view. It saves us a lot of time so we can help others. This time I'll help you about a bit and run it through a word processor. Thank you, Adam J.> Local Beach Sand, Not a Good Idea 10/4/05 Hi Bob. <No not Bob. Adam J responding to you tonight.> I'm a newbie so please bear with me , not that I'm cheap but can I start my reef tank with sand from the local beach ? <Generally not a good idea, most American 'beach-sand' is filled with silicates. At the least they cause horrible diatom growth.> I live in Long Island N.Y. There are lots of drift wood, rocks, I liked to take that is of course if it's legal, think its possible ? <You would have to check with the local authorities as far as the legality of such collection.> Rich R. <If I may ask a favor of you, please capitalize and add appropriate punctuation in future queries. Adam J.>

Advice on Marine UGF 9/28/05 Hi guys (and gals), greetings from England. <Mmm, am from Rhode Island... often confused with Mars> My question mainly revolves around the UGF and gravel that I was mis-sold by my LFS (Have recently changed due to the bad advice given by said LFS). I have had a Marine tank set up for 6 weeks now ( it's my first) that I want to run it FO and then once it matures (and I become confident in my husbandry) introduce some inverts. It has cycled already (NH3, NO2, NO3 all at zero after rising and falling) Here is the spec: 150 litres (48"x12"x18") 3Kg Fiji LR (Couldn't afford any more!) and lots more base-rock that'll hopefully become seeded Fluval 4Plus Internal Filter UGF with 2X 600litres/hour Powerheads attached to 1" uplifts 1.5 - 2" gravel (not sure what this is called - see attached picture. The grains seem to be 3mm - 5mm on average with a few crushed shells etc - any idea what this is?) <Coral... coarse sand, rubble... natural product> 1 Marine White NO Flour 40W 2 X Marine Glo (Blue) NO Flour 40W (soon to be replacing one of the blues with a Marine Life) Some Caulerpa that came on the Live Roack Various bristleworms, copepods and spaghetti worms A sump is not really an option (I know you guys favour this!) <You've been reading> My plan was to buy a Protein Skimmer ASAP (next week) and get this up and running, adding more live rock (curing it as I get it of course) as I go as I cant afford to get it all at once. I was also going to add 2 Ocellaris clown this weekend and see how I get on with these for a couple of weeks before adding any other livestock. <Okay> My main concern now is that the UGF is going to act as a Nitrate factory so I'd like to "replace it" with something more appropriate. I don't really have the option to go out and buy another 20Kg or live rock due to money restraints (I will be buying more over and extended period of time though) so was thinking instead of using a canister filter such as a Fluval 304 or similar. Would this be a good way to go? If I then replaced my existing "gravel" with a DSB of 3" of super fine sand would I eventually be able to do without the 4plus internal filter as well? I have assumed from reading your articles that the existing gravel (see picture attached) is totally unsuitable for a DSB. Would I absolutely need to remove the filter plates when using the super-fine sand? <Mmm, well... you could just wait here... less disruptive... and take out the plates later... better to focus on your added skimmer, live rock at this point> Assuming it would be best to do this before I put the Clowns in, how long would I realistically have to wait after replacing the substrate before I put them in? Any help would be greatly appreciated. I have read most of the FAQs in this area, but cant really make sense of my predicament! (Conscientious Marine Aquarist is on its way via Amazon!) Cheers, Chris. <Ah, yes. Know the author. I would leave all you have as is for now... not too many years, places ago, your set-up was the standard approach... Can/will work... with a bit of extra maintenance, less margin for "errors". Cheers. Bob Fenner>

Sandbed On The Move? 9/28/05 Hey Crew, <Hi there! Scott F. here today!> Apologize for the question but not seeing my problem directly. <No need to apologize!> Currently have a 75g mainly FOWLR (couple of mushrooms and a few polyps) with ~65 lbs LR and a 4-5' DSB. I'm sold on the DSB idea; tank has been up for 3 years and since initial cycle, nitrate and nitrites at zero. <Good to hear!> Moving across town in a few days to a new house where I'll be setting up a 145g display on the main floor along with a 75g sump and 33g refugium in the basement. Problem is the new tank and sump still haven't been delivered and realistically if I had them now, probably wouldn't be plumbed for a couple of weeks. Concern is maintaining the DSB. Was thinking, taking the 75g down, saving top 1' layer of sand, moving everything across town in tubs. Once there, fill the 75g back up with SW that's currently at the new place aging (power heads and heater) and the LR. The sand I saved, I would place in the 33g with a HOB filter and power head to keep for seeding the DSB on the new system. The move is going to be complicated enough as is, so wondering if it's worth the effort in trying the keep the sand or just toss it? <I'd hate to totally waste the established sand bed, but there might be some die off of the infauna and bacterial populations within the sandbed once it's disturbed and moved. Expect some possible "re-cycling" to occur. It's certainly worth a shot, if you are up for the effort, IMO.> A some what related question, if I were just to have Â½' sand in the display and setup a remote DSB in the sump and/or refugium what would be the minimum surface area for maintaining NNR? <Hard to say, actually. I'd tend to use the "depth" as a gauge for denitrification capacity. I wouldn't run less than a 3"-4" sandbed in the sump if denitrification is what you are attempting to achieve.> Finally, thanks for the site; it's amazing the amount of info. In addition to the reading online, I've probably a stack of FAQ's printed 18' high (all two pages per sheet, most double sided). Great reading when on the road or when someone else is on the computer and I need a WWM fix. Mark Edmonton, AB <A great idea...You CAN take it with you! Good luck on the move! Regards, Scott F.>

Substrate and Live Rock setup - 9/16/05 Hi guys, hope all is well and that the hobby/trade is continuing to fascinate you and provide you with much enjoyment. <Always> A quick couple of questions about substrate and live rock if you don't mind! <Sure> I've almost set up my 47G marine aquarium having spent a couple of months reading/learning and building from scratch using the best equipment I can afford (as recommended by your good selves!) <Excellent> The tank has just cycled after only 10 days since having put in 20KG of premium uncured Fiji live rock. <10 days eh? I would give it another two weeks> Now, I intend to aquascape using 2-part epoxy (I intend to build 2 reasonably flat bases of ocean rock on which to affix the live rock) but need to ensure I have the substrate right first. <OK> I have no U/G filter <Good> and intend to place the rock directly on the sand - this being CaribSea 0.5mm - 1.0mm Aragonite sand. <What I have done as well. In fact I have the same substrate too> IYO should I leave in the 3" depth or reduce to perhaps 1" or 2" (I'm concerned about Anoxia you see)? <3-4 inches or more is ideal You could place the rock at the 1inch mark and then fill around the rock for more stability if you want. This is what I did>> Secondly, I filtered and skimmed full pelt during the curing process of the live rock yet it has mostly died (it is pretty bleached) with the biggest part of the Coralline algae losing it's colour in the process. <Actually quite normal regardless of external filtration and skimming methods. Not abnormal at all> Would you suggest the rock will again become infested with life, and would 5KG of cured live rock be sufficient to assist in the seeding of the old rock? <The rock will again, over time, be alive with coralline growth and sponges. Need months to years in some cases. Add as much Live Rock as the tank will support (think within your aquascaping) and you can afford.> Many thanks in anticipation of any response/help, and - yet again - u guys r the best! Steve Morse <Thanks Steve.>

Crushed Coral Substrate 9/13/05 Hey guys, hope you're doing well tonight. I want to thank you once again for preventing my tank from becoming a 1,000 pound paperweight. <Many of them out there> Anyhow, onto the question of the day. I have a 100g reef tank with a crushed coral substrate. I know that crushed coral is notorious for trapping detritus, but I was wondering that if the substrate has noticeable amounts of amphipods running around, along with bristleworms and a whole host of other things when the lights go out, is crushed coral still good or is it just too much of a nitrate magnet. More to the point, with the increase in detritivores (and regular water changes) will nitrates ever become an issue. I'm loathe to vacuum the substrate because I know I'm pulling out tons of little creatures each time I do. Any help would be appreciated. <Clay, nitrates develop from high detritus levels resulting from uneaten food, fish waste, etc. In your case the critters in the substrate are helping in reducing the waste. You didn't mention your last nitrate reading. If it is 20 or lower you should be OK. You didn't mention the use of a protein skimmer. These will also help lower nitrate levels to acceptable levels. Search our WWM, keyword, "nitrate control" and read on this subject for additional help. James (Salty Dog)>

Crusty sand 9/11/05 Hello All! I have a quick question regarding my 40 gallon mini reef tank that is seven mos. old. Details of the tank are as follows: 30 lbs live sand, 40 lbs live rock, Remora hang on skimmer powered by an AquaClear 802 producing about a half cup of greenish brown scum every two days. A AquaClear 30 and Maxi-Jet 1200 providing circulation along with the return from my XP-2 canister filter. 36 watt Coralife U.V. filter with a measured flow of 180 gph passing through it. Although the XP-2 is rated at 300 gph, I've found that with the filter media in place (two 30 ppi pads, two 20 ppi pads, phos-sorb, Chemi-pure and one micro filtration pad) my output is actually 180 gph. <Yep, about right> Lighting is an Orbit 30" with dual 65w daylight and dual 65w actinic. pH is 8.2, ammonia 0, nitrate 5.0, nitrite 0, phosphate 0, Alk. 5 (trying to raise with Seachem Reef Carbonate), calcium fluctuates between 580 and 610. <... way too high... if accurate, the primary reason/cause of your low alkalinity> I do not add any additives other than the Carbonate which I just started adding a week ago. <... check your salt mix brand... change it... likely Oceanic> Temperature is 81 degrees. Livestock consists of 1 turbo snail, 3 margarita? snails, 4 brown hermits, one blue legged hermit, 1 medusa coral, 1 green open brain coral, 1 pink feather duster, 1 fire shrimp, 1 lawnmower blenny, 2 tomato clowns and 1 coral beauty. <Crowded...> I do weekly water changes of 5 Gal. All water used is R/O. Finally to my question. The top layer of my sand bed, which is about 1 1/2" deep, gets hard and crusty and turns a shade of crimson to rusty brown in color. Is this a bacteria? If so how can I treat it? Thanks, Eddie <Is chemical/physical... the reaction products from your too high calcium et al. and carbonates, bicarbonate... Please read here re: http://www.wetwebmedia.com/calcalkmar.htm and the linked files above. Bob Fenner>

Re: Crusty sand 9/12/05 Thanks for the info Bob. Am I to understand then that when I get the calcium down to acceptable levels the crustiness of the sand will go away? <Mmm, won't be added to... the crust that's in there now will have to be removed, broken up. Bob Fenner>