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FAQs on Carbon Filtration 2

Related FAQs: Carbon 1, & FAQs on Carbon: Rationale/Use, Types/Qualities/Selection, Placement, Renewal, Negative Reactions, Sources/Brands, & Marine Chemical Filtrants

Related Articles: Selection and Placement of Activated Carbon in Marine Aquaria by Adam Jenkins,  Phosphates in Carbon; An analysis of the phosphate content of activated Carbon by Steven Pro, Marine Chemical Filtrants Zeolite Filters: A Discussion of What Zeolites Are and How They Function by Jens Kallmeyer,


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Marine Aquarium Algae Control

by Robert (Bob) Fenner

"Reactivating" Activated filter carbon    6/23/12
Hi crew,
I just wanted to follow-up on a question I posed a while back.  I think I a partial answer that I'd like to share with you.  If you think it would be of value to your readers, feel free to post/share. 
<Thank you>
My original question asked if it were possible to regenerate activated carbon.  Yes, I'm cheap.  But more than that, I'm practical and like the sustainability aspect of this idea.  While I could rinse and throw my old carbon in the garden, I'd simply like to re-use it.  My initial thought was to resubject it to >500oF temperatures for a period of time.  I don't claim to be a grille master, but I seem to be able to make my own "carbon" by over cooking the burgers.  So, I figured, if I just applied my skill to my old carbon..  you get the idea.   As I understand it, our carbon, while in use, is adsorbing into is microscopic pore molecules like dyestuffs, iodine and other large molecules.  A great test is to pour Kool-aid through a bed of this and see the drink come out of the carbon colorless (although just as tasty).  The dyestuff is retained.  Well, those dyestuffs, colors and other large molecules are all just complex organic molecules.  I'm sure with enough heat they can be reduced to CO2, carbon and a few other trace elements (P, N, S, etc.) just like my burgers.
<For the most part, yes>
So, I put it to a test.  I put 4 cups of my spent carbon that was in use for a couple of months (nasty smelling too) into a Corning bake ware dish and set it into a 525oF grille for about 45 minutes.  After allowing it to cool down (and cleaning the inside of my dish back to white), I reused the carbon.  Note:  the carbon was odorless after coming off the grille and cooling down.  The carbon was used in my DIY carbon pre-filter on my RO/DI unit.  AND there were no detectible levels of Chloramine/Chlorine exiting the carbon chamber.  The feed water contains >6 PPM chloramine.   In my aquarium, the water had a slight yellow tint.  After 36 hours of filtering with a Magnum canister filter using only 2 cups of this carbon, the 170 gallons of aquarium water was near colorless to the eye.
I don't know to what degree carbon can be regenerated.   I presume of the dyestuff turns to ash inside the pores at >500oF.  Repeating this process may eventually clog the pores.  I presume the carbon may slowly loose activity with this kind of regeneration, but it does seem to work.  I supposed for carbon used to remove potable water chloramine (pre-RO treatment), the Chloramine will oxidize to Cl2 and NOx and subsequently off-gas.
I thought I would share my knowledge and invite anyone else with ideas on the subject to build on this.
Happy reefing,
Steve Ghera
<Thank you again for this report. Bob Fenner>

Phosphate/Carbon Reactors -- 03/08/10
<<Hello Jeffrey>>
I recently changed from a 20 gallon long to a 40 gallon breeder sump.
<<Bigger 'is' better'¦>>
I also changed my setup a bit and took out the Ocean Clear filter with its carbon bag, and replaced it with a 200µ felt filter sock. When testing after one week with this new set up, we found ammonia at .5.
This was the first time that I ever had noticeable ammonia in this tank.
<<Hmm'¦ If this is a result of simply removing the carbon filtration then you have bigger issues here, as in an overstocked system maybe>>
We immediately did a water change, and placed a large amount of carbon (the one that fits inside the Ocean Clear filter) inside of the filter sock. This being just done, I am uncertain whether or not the carbon will do the trick.
<<Indeed...though it seemed to 'do it' before. I would also add some Poly-Filter'¦and start trying to discern the source(s) of the excess nutrient load>>
The reason for omitting the Ocean Clear filter was, I must admit, to alleviate a bit of work as cleaning those filters are a pain in the neck!
<<A simple canister filter utilizing carbon/Poly-Filter would suffice>>
But, on the other hand, cleaning the filter sock at least weekly means less possibility of buildup from the crap it traps. It doesn't stay in the sump long enough to create a problem.
<<Your water tests may be indicating otherwise. Perhaps a 'twice weekly' cleaning is warranted>>
I am planning on purchasing the "Two Little Fishies" media reactor, coupled with a Maxi Jet 600.
<<Ah yes'¦ This and other 'fluidized' reactors work very well as carbon/chemical filters>>
Actually, I am planning on purchasing two: one will be for PhosBan, and the other for activated carbon
<<Excellent'¦ And do be aware that GFO is GFO (Granular Ferric Oxide)'¦the Two Little Fishies product is good stuff, but there are cheaper brands/sources about>>
(I currently am using Marineland Black Diamond, but am considering switching).
<<The same goes here'¦>>
Also, I must not omit telling you that this tank, a 120 gallon, also showed signs of phosphate about a week ago.
<<All this as a result of/coinciding with the sump upgrade? Did you perhaps stir up a large amount of detritus in the old sump that was pumped to the display?>>
Those signs are gone as of last night, however I feel that the reactors services will not go to waste.
<<Likely not>>
I question the need for carbon in a reactor as opposed to placing it in a media bag inside of the filter sock, so I would appreciate your input on this.
<<The reactor is a much more 'active' and efficient means of utilizing the carbon in my opinion>>
The price of the reactor and pump is minimal compared to the cost of coral, of which I have lost a few through this ordeal.
My aquarium is as follows:
120 gallon Oceanic on high stand
Approximately 100 pounds of live rock
Sand bed (not deep)
Nova Extreme T5 (8 x 54 W)
Precision Marine Bullet One protein skimmer coupled with Sedra 12000
Eheim 1262 return
Iwaki 30 return (used to be to circulate Ocean Clear and UV Sterilizer)
36 W Turbo Twist Sterilizer
Any advice regarding what I have mentioned will be greatly appreciated.
<<You likely should consider the addition of a macroalgae refugium w/DSB to assist with nutrient export'¦among other benefits>>
Jeffrey Castaldo
<<Be chatting'¦ Eric Russell>>

Hair Algae and it's "Nemesis"?!?   8/24/09
Greetings to my favorite people at WWM!
<Hello to you Jamie>
Interesting observation that I like to share with you. I currently have three tanks. Their parameters are all very similar as I use the same RO water mixed with Coralife Reef Salt and I perform a 15% water change on them every week. There are only TWO differences (Okay, I'm painting with really broad strokes!) - they are the inhabitants and the presence or not of CARBON in the filtration system.
<Mmm... often there are other more subtle diff.s, but let's see...>
Tank 1: Carbon; Green Spotted Mandarin Goby, Barnacle Blenny, Eyelash Blenny, Yasha Hase Goby, Pistol Shrimp, Peppermint Shrimp, Skunk Cleaner Shrimp plus Hermit Crabs.
Tank 2: NO Carbon; Flame Angel, Bicolor Blenny, Black Percula Clown plus Hermit Crabs.
Tank 3: Carbon; Rainbow Fairy Wrasse, Flame Hawk Fish, 2 Pajama Cardinals, Lawnmower Blenny, Pink Spotted Watchman Goby plus Hermit Crabs.
Tank 1 and 3 have been infested with hair algae over the past 4 months.
Tank 2 have consistently been without hair algae or slime algae, not even a hint!
All tanks have been set up for more than one year and I do the same routine for all three tanks, feeding in the same fashion. Tank 2 is the "cleanest", absolutely no signs of hair algae and the tank has a general clean
appearance - minimal detritus on rocks and macro algae where the other two sometimes get that dirty, ash covered look and lots of stuff to blow off during my weekly water changes.
For several weeks, I was thinking that maybe the carbon was leaking something back to the tank to encourage algae growth, but I renew them with fresh carbon every two weeks, so maybe just the presence of carbon... Then today I did an experiment during my weekly water change. I took a green hair algae and red slime algae covered water return from Tank 1 and swapped it with the coralline covered one from Tank 2. Within five hours, that return is cleared of all green hair and red slime algae! Yippi! Well, now, I'm guessing that one of the inhabitants in Tank 2 is having a feast eating this stuff, I just can't decide if it is the Flame Angel or the Bicolor Blenny.
<Could be both, either>
My bet is the Bicolor Blenny but the Flame Angel is the one showing most interest. As I'm writing this, I placed a piece of hair algae covered Zoanthid in the front...I want to watch nature in action, and so far, the
Flame Angel is the one showing interest.
Thank you, each and every one on the WWM team, for creating this site that helps all of us fish lovers to not only learn about the wonderful creatures that we share our earth with, but also encouraging sound stewardship to these wonderful creatures!
Jamie Barclay
<May, might I suggest an experiment with the carbon? Do soak some bit, a tablespoon or so, in a jar of your RO water for a day or two and test for soluble Phosphate... Some "brands" do leach this often rate-limiting noisome algae nutrient. Cheers, Bob Fenner>

Re: Refugium Macroalgae, carbon use  - 08/13/08 Hey Eric, <<Hey Jennifer>> Thank you for the quick response! <<Quite welcome>> Ok, I feel much better about what I'm doing and picking the Gracilaria. <<Ah, good>> As far as my water I've got an RO/DI and I mix the salt and water up in a 60 gal Rubbermaid garbage can and let it sit for a week...of course there is a powerhead in there. <<Of course [grin]>> It lasts for about a month. <<This is fine…you could even add a cup of water from the display a day or two after mixing to help with maturation. This bacterial "booster-shot" so to speak, may even help with any residual Nitrogenous compounds that might be in the salt mix>> Question: I change out the carbon weekly...recently I've read that carbon can be left in for up to a month...what's your opinion? <<Mmm…carbon is thought to be "used up" fairly quickly, though this can be affected by the quality/type of carbon and the level of ions in the system suitable to/available for scavenging. Some authors have recommended changing carbon as often as once a week as you are doing now. Some thoughts behind this are that the scavenging capabilities of the carbon will be exhausted in this time (as alluded earlier), and that letting the carbon remain in the system allows it to be colonized by bacteria and turns it in to a bio-filter which will then begin to contribute to the Nitrate level of the system (a concern primarily to reef hobbyists). Concerning the first issue, this is likely true for most systems in my opinion. In fact, I think I recall Bob mentioning that some carbons are exhausted in mere hours to days. I don't know of any simple tests to determine when your carbon has "done its deed" considering the other factors/ancillary filtration going on in a system that could affect results. But if you are not utilizing ozone, the easiest way to measure when you need to replace your carbon may be to monitor your water clarity…considering carbon's penchant for removing "coloring" agents. As for the second issue, I think the small amount of carbon most hobbyists employ will have little if any negative impact when colonized by bacteria. A third concern to leaving carbon "too long" in the system is the fact that it is an "adsorbent" material, meaning it causes substances to adhere to/be trapped by its internal structure but it does not change its physical or chemical properties. In this sense any trapped organic material will begin/continue to decompose as long as the carbon is left in the system. It is also thought that once the carbon is "full-up" that it can/will begin to release trapped compounds back in to the water. This is probably the most compelling reason, in my opinion, to change out your carbon on a frequent and regular basis. So, getting back to your question… Leaving the carbon in your system for a month at a time between change-outs is probably not going to cause any serious problems…but leaving it in for more than a couple weeks likely also means it is not providing the intended benefit. Understandzee?>> I'm very careful to wear plastic gloves that go to my shoulders for cleaning and I rinse all of their food to eliminate pollution/phosphates. <<Very good>> Will raising the pH hurt any livestock? <<Not if done slowly, in my experience (no more than two-tenths in a 24hr period) I'm mostly concerned about a starfish and coral banded shrimp. <<Should be fine>> I'm going to give the semi-weekly water changes a try. <<Excellent…do let me know how this goes/what you think>> Thanks for all of your help!! Jennifer <<A pleasure to assist. Eric Russell>>

Use of Carbon 7/28/08 Hi Crew, <Hello> Instead of asking a question I am reading, but having a problem understanding. http://www.wetwebmedia.com/chemFiltrMar.htm -by Bob Fenner In the above article I am having a problem understanding the paragraph below. Could you explain it in more detail? Carbon Shock: There is some danger, especially in full-blown reef and intensive invertebrate systems of removing too much dissolved organic carbon too quickly. Some of the adsorptive matter is biologically important (pheromonal...). For these systems that have had no steady history carbon filtration Wilkens and Birkholz (1986) suggested working in an additional 1 1/2 ounce per twenty six gallons per month. Other authors estimates are less restricted than this value. The best measure of how much is right is best gauged by close observation of your livestock. <Bob may have more to say here (he did write it!), but the basics of this is change in your system too quickly if carbon is not consistently used and then applied. This can shock your livestock purely from a water chemistry standpoint or the fact that you will all of a sudden have greater light penetration, leading to the livestock receiving more intense light.> Thanks <Welcome, I hope this helps, Scott V.>

Additives 07/28/2008 Hi Crew, <<Good evening, Andrew today>> If I want to add Selcon to the water once a week or any minerals do I have to remove carbon or poly filters and if I do for how long. <<I would, yes, leave off for a couple of days. The question is, do you really need to be adding these to your tank? Is a test showing up a deficiency? Add the Selcon direct to the food prior to feeding.>> <<Thanks for the question, hope this helps. A Nixon>>

Bio Balls, Carbon - 6/25/08 Conflicting advice about bio balls and carbon Lately I have received conflicting advice about the use of bio balls and carbon in my reef tank. I was told that carbon filtration should only be done periodically or it will remove all the essential elements necessary for good coral growth. <Mmm...not 'true' per se, but can remove certain desirable organic compounds, salts> I was also advised to replace the carbon in my Fluval filter with bio balls. <I'm not a big fan of bio-balls, as they tend to get gunky. Fired ceramic?> I have your site bookmarked and trust your advice. So here is my setup: 46 gal hex with lots and lots of live rock (running 7 months) Live sand about 1/2 to 1 inch deep 20,000 K metal halide Sea Clone protein skimmer <Is this removing good skimmate? If so, bravo...but I know a lot of people who have trouble with these...poor design> Fluval 304 (with ChemiPure, bioballs, filter pads) All test parameters look good (added 2 fish and bioballs this week and nitrates rose, but only to 20) Fish: yellow tang, 6 line wrasse (new), royal gamma (new), blue green chromis, yellow tail damsel, black and white striped damsel <Note: A 46 gallon of any shape is far too small for a tang, much less a hex. They need at least 5-6 feet of uninterrupted swimming space> Corals: Hammer, 3 small Kenya trees, Ricordea (Sm),  Inverts: 1 cleaner shrimp, 1 banded shrimp, 2 serpent sea stars, lots of crabs and snails, 1 small spike urchin My goal is to get coral going to add movement to the tank ( I have water pumps running). So, what would you advise about bio balls and carbon usage? <Read around wetwebmedia.com re filter media> Should I add chemicals to help the corals? <With Scleractinians, Ca+, alkalinity supplements...water changes should handle the rest, provided you do them regularly.> Can I add macro algae to the tank for the tang and to look pretty? <I wouldn't. It can really take over- and that tang just needs a bigger home, period.> I do not have a sump or refugium at this time. I have been doing 5-10 gallon water changes weekly so far. <Good. Keep them up!> Thanks for all your help. <No problem. Benjamin>

Chemi-Pure Sucks... I Think????? - 04/01/08 I Recently put a bag of Chemi-Pure in my 46 gal bowfront tank thinking it was gonna help. <<Help what?>> Not 24 hours later mushroom corals melting and flame angel is short on breath. <<…?>> Pretty sure he's gonna die. Fungia is no longer extending tentacles and my seahare doesn't look like it's doing to good either. I guess the real question is.. by me changing out regular carbon and adding Chemi-Pure, the amount suggested by the bottle, I was wondering if the addition of too much carbon or whatever Chemi-Pure has is what made this happen?????????? <<Not typically, no…especially if you followed the manufacturer's instructions. If indeed the Chemi-Pure is at fault here, it's hard to say what may have caused this reaction as you have provided no information re water chemistry/tank conditions, before and after applying the Chemi-Pure. This is a good and well thought of product, but do remove it and see if things improve. I suppose there's always the possibility of some type of contamination…though I suspect there are other factors at play here. Regards, EricR>> <More likely the Seahare itself is the cause of issues here. RMF>

Carbon and reef tanks, 3/22/08 Hi guys, Ben here. <Hello> I went into the LFS today to restock on some carbon. Now when I purchased it the LFS guy told me that I should never ever use carbon in a reef tank, as it will strip all magnesium a calcium. And that I should only use bio chem Zorb as it will not take away any trace elements. <How much more expensive was the Bio-Chem Zorb?> Now I've done lots of reading here about carbon use and I've been using it. But can someone set me straight (he made me worried) is it ok to use a normal good quality phosphate free carbon in a reef tank? I mean I bought the bio chem Zorb. But can I still use a normal good quality carbon? <Yes the carbon is fine, it could not possibly remove enough calcium and/or magnesium to make a big difference.> Please put my mind at ease. Thanks so much for your time. Ben <Welcome> <Chris>

Carbon and reef tanks, A reader adds on 3/22/08 Hi there Crew, <Hello> Love the WWM website, try to read it every day. on 22/3/08 Ben asked about carbon/"Bio Chem Zorb" in his reef. I have used both extensively over the years so no worry there that I am aware of, but I'd like to point out that "Bio Chem Zorb" is mostly small carbon beads with some ion exchange media mixed in. Ben - your LFS guy is full of the proverbial! <But I bet it has a nice mark-up over the plain old carbon.> Cheers, MickT PS just starting set up on my new 180 gal - may be back with some questions of my own ;-) <Good luck with the new tank and thanks for the comments.> <Chris>

Re: Carbon Question  3/26/08 Just wanna thank Mick T. I just read what you said about the bio chem Zorb. And yes it was double the price! <Not surprising.> And thanks Chris. I will go ahead and continue my use of carbon with out any worries. Loving my reef tank!! After 7 years of breeding discus its a very cool change! Cheers guys. Ben <Good luck> <Chris>

Carbon in filter -11/11/07 Dearest Crew, hope everyone is well. <quite, thank you> I have a Fluval 404 for a 40 gal. tank, and when replacing the carbon in the filter I was wandering if it needs to be rinsed until the water runs clear, or just rinsed for a minute or two to remove the dust as stated on the carton it came in. Any idea? <I believe the later plus a little more. It would take a whole lot of rinsing (too much) to make it run completely clear.> Thanks again guys Amanda <De nada, Sara M.>

Activated Carbon and neuromast destruction... Not  9/26/07 Dear Crew, I always believe that carbon is not the culprit that causes hole-in-the-head but many hobbyists out there still believe so. Pls. clarify. <It's not> Thks. in advance. Regards. Alan <Please... read here: http://www.wetwebmedia.com/hllefaqs3.htm and the linked files above... the search tool, indices... Bob Fenner...>

Cleaning Carbon Hi Bob, <Richard> Maybe a silly question.....but do you have any tips on how to clean dusty carbon before putting it in the sump? I have some Kent Reef Carbon I would like to use, but always find that no matter how many times I dunk it in a container of RO/DI water....the carbon releases black junk. I am afraid to use it since I do not want the dust to enter my tank. I have put the Kent Reef Carbon on the shelf and am using Aquarium Systems Black Diamond carbon. Less dusty. Thanks Rich Maurin <Not silly, or... at least we're about the same silly... I rinse new, dusty carbon (and other filter media) in either the "Dacron" bags it comes in or I put it in, or just in a net (in the sink with running freshwater) ahead of placing it. Bob Fenner>

Protein Skimming or Activated Carbon...Or Both? Does carbon treatment and Protein Skimming do the same thing? <Good question. They both do assist in removal of dissolved organic compounds. However, carbon can also remove substances that discolor the water, such as tannins, some dyes, etc. Protein skimming does a great job removing many of the same substances, but uses the principle of electrostatic attraction to "grab" dissolved organics and "stick" them to the surface of bubbles. A good skimmer will remove a tremendous amount of materials from the water, and, unlike carbon, a skimmer does not have a "useful life". However, in order to do the best job possible, a skimmer needs to be cleaned regularly (like weekly or more often). Ironically, the very "crud" that a skimmer removes so well can accumulate and inhibit foaming! By keeping your skimmer clean, you're assured that it will perform at its best at all times.  In the end, I think that a marine system should be run with BOTH carbon and skimming. Hope this helps! Regards, Scott F.>

Carbon Causing HLLE? Hi Crew, thanks for taking my question. <Sure! Scott F. with you today!> First let me give you a brief history of my situation. I have a hippo tang that developed hole in head disease early on. It is stable (some scaring around the head) and has been there for about a year and a half or so. Anyway, he developed ich a little while back, I believe it was from a wrasse that I added without quarantine. <A lesson learned, huh?> I put all my fish, 1 tang, 2 clowns and the wrasse in a 35 gallon plastic container (quarantine) for 8 weeks while I let the tank run fishless to get rid of the parasites. I decided to use the  "siphoning bottom of tank everyday" method to cure (no copper) and it worked great. <Well done! Glad to hear that!> Now to the point. During the eight weeks in quarantine, my hippo tang showed tremendous improvement regarding the HLLE, the scarring around his head was reduced by at least 50%. Problem is, I put him back in the display tank and all the progress has reversed and the scaring went back to the way it was. There is no way the water quality in the quarantine tank was better than the display. I was using tap water, a power head, a heater and a sponge filter. The display tank  gets RO + DI water, 20% bi weekly water changes, live rock, live sand, better diet, steady temp, etc. So I figured it was the lack of carbon use that helped reverse HLLE. I did not use Carbon at all in the quarantine and run it constantly in my display tank. So I want to experiment and stop using Carbon in my display tank. <Well, that could be one possibility...I'm quite skeptical, because use of carbon far outweighs any possible ill effects that could happen, IMO. Yes, some people claim that carbon depletes trace elements, but if you are conducting regular water changes, this argument doesn't hold up, IMO. Anecdotally, you could proceed under the hypothesis that carbon contributed to the HLLE condition, but I don't know how it will work out. An interesting experiment, however. I commend you for trying! Do consider other possibilities, such as "stray voltage" in the display tank, or other possible environmental factors, too...Test for all of the basic parameters, and then some!> Will this effect my Coral in anyway? I have a Bubble, Torch, Candy Cane, Various Polyps and Xenia. <Well, activated carbon helps remove all sorts of allelopathic compounds that are released by corals on a regular basis. You might see some differences in the health of these animals if you discontinue its use in this tank.> Should I increase my water changes, or is it not necessary? <I'd consider more frequent water changes to help compensate> Will the protein skimmer pick up the slack? I use a Aqua-C Remora. <Aggressive protein skimming will definitely help, too.> Thanks for you input. Ang. <My pleasure, Ang. Do test your theory, but also look at other possible factors along the way...I'm sure that you'll have some interesting results to report! Good luck! Regards, Scott F>

Point-Counterpoint... Thanks for your time on this. <Our pleasure- we love this stuff! Scott F. here today> I have been doing a lot of research on marine aquariums (books and internet searches) and what I am finding is that there are a number of diametrically opposed views about the aquarium. <Different views? On marine aquarium keeping? Really? LOL> I have read enough articles on WetWebMedia to know what you believe and I would like your opinions on some of these differing thoughts. <Sure- I'd be happy to!> 1) It is a universally accepted principle that aggressive protein skimming is a must (1 cup a day) for nutrient and allelopathy export.  In addition, to successfully grow corals, micro-organisms such as zooplankton, phytoplankton, etc., (whether grown in a refugium, a reactor and/or green water additives) is also a must.  However, protein skimming removes these micro-organisms from the system and there some thought that protein skimming is as harmful as helpful.  The no-protein skimmer belief rests upon refugium/Caulerpa/seagrass and/or clams as a more natural mechanism.  Plus, there are less impellors killing the organisms (including powerheads). <Well, I am of the opinion that a well-tuned protein skimmer is absolutely essential for long term success in closed marine systems. I have heard from a number of people who yanked their skimmers-some have been successful for a while- many have gone back to skimmers. I like to think of the long-term with reef tank maintenance. Skimmers remove many noxious compounds and dissolved organics before they have a chance to degrade water quality. I have yet to see a very successful reef system that has been maintained for years without skimming. I do not consider  one or two years a success...The bottom line on skimmer use, in my opinion, is that if you are going to omit skimming, then you need to compensate somewhere- either with a much lower bioload, very aggressive water change schedule, alternative "filtration" techniques (like Steve Tyree's Sponge/Sea Squirt Cryptic Zone concept, etc.). It is a trade off, and one that I do not feel is worth it. As far as the impellers in pumps destroying valuable plankton is concerned- I have heard a lot of thoughts on this, and, quite frankly, I feel that the threat-although legitimate, is highly overstated. Most reef systems simply don't grow and support large enough populations of plankton for this to be a legitimate concern, IMO. Even with productive refugia and other supplemental systems, I just don't think that the impact is there> 2) To remove allelopathic compounds from the system, weekly carbon changes are suggested.  However carbon also leaches vital trace elements out of the system.  Once again, harmful and helpful. <I am a firm believer in the continuous use of small amounts (like 2-4 ounces per 100 gallons of tank capacity) of high quality activated carbon. Good grades of carbon, such as those offered by Seachem (my personal favorite), Two Little Fishies, or ESV do not leach phosphates into the system. Yes, carbon can remove small quantities of trace elements from the system. However, if you are following one of my other favorite practices in marine husbandry, frequent small water changes- you will be replacing trace elements on a regular basis. In fact, you will probably not experience a deficiency in trace elements if you practice these water changes> 3) Another universally accepted principle is weekly water changes.  When you have a 55 gallon tank, a 10% water swap is no big deal.  When you have a 125 with a 30 gallon refugium and 10 gallon sump, it is a much greater effort, requiring a large garbage can sitting in the living room overnight to allow the salt to fully aerate and mix before doing the swap.  Plus the swap tends to be somewhat stressful on the fish.  I am planning on buying a 300 gallon at the end of the year and turning the 125 into a large DSB/Live Rock sump. A 10% water swap on 425 gallons will be a huge effort! <As a fanatic about regular small water changes, I can tell you that the process is simply not that difficult. One of my systems has about 200 gallons total capacity. I change 5% of the water twice a week. This amounts to 2 10 gallon water changes, which I perform on Wednesday morning before work, and on Sunday mornings (unless the surf is good- in which case it's usually Sunday afternoon!). I will generally mix up the saltwater in a Rubbermaid container about 24-48 hours before, and then perform the change. I also perform minor maintenance tasks, such as a little extra algae scraping (if needed), coral pruning, etc. on Wednesday. This will take about 20-30 minutes to perform. On Sunday, I take a little more leisurely pace, and will clean the skimmer, replace carbon or Polyfilters if needed, change micron socks, or any other little things that have to be done. Maybe it takes about 45 minutes to an hour of pleasant labor. I have always done the additions of new water "manually", by pouring it into the tank from a pitcher. If I really wanted to do it quicker, I'd hook up a Maxijet 1200 powerhead to some 5/8 ID tubing, and "pump in" the replacement saltwater...it's a lot quicker. Frequent small water changes need not be a chore. Rather, look at them as an opportunity to regularly assess the situation in your tank. Anyone who maintains their own garden can relate to the labor involved. It is part of the "price of admission", IMO, and is simply not that difficult. And, when you see the difference in your animals, you'll realize that it's all worth it!> Lastly, I have and read about many a aquarist who has been very successful for years with minimal swaps, minimal effort by maintaining proper trace elements/calcium/alkalinity. <I have to quote Anthony on this: "Even a blind squirrel finds a nut sometimes!". It's just not something that you'd want to do. We are talking about living creatures here- which require us to provide the highest level of care. Closed systems are just that- closed, and unlike the ocean, do not afford the animals a constant influx of clean water. To those hobbyists who think that water changes are not required, I respond, "You wouldn't let your dog live in the same room for 5 years without cleaning out the waste, would you? Don't do it with your fish!"> 4) Bio-wheels and Bio-balls are sold in virtually all LFS and internet dealers.  They add a tremendous amount of stability to the system but also contribute nitrates because there is no anaerobic area for denitrification. Once again, stability vs. water quality, harmful and helpful. <These media are, in essence- "victims of their own success": They are so good at removing nitrites and ammonia, that they cannot provide a bacterial population to keep up with accumulating nitrate. Yep- it is a tradeoff. Frankly- I like to keep things simple, and use a more natural approach: Let the live rock and sand do your filtering, along with use of macroalgae in refugia, and protein skimming, water changes, and regular use of carbon and/or PolyFilter media.> 5) Allelopathy is another subject, not discussed at LFS trying to make a sale.  Some people claim that pictures of beautiful coral displays that are all over the internet will be very different a year from now because of allelopathy and others claim success for years in spite of pictures showing many corals side by side, touching each other.  Another subject in dispute. I have purchased very aggressive corals (not knowing better at the time).  I have multiple leathers, Ricordea mushrooms, 5" genitor, frogspawn, colt and bubble corals.  Is this a toxic soup, a ticking time bomb, or as others claim, no big deal. <Well, I would not call it a ticking time bomb, but it is not an ideal situation. This is an aggregation of animals that are rarely, if ever found in close proximity to each other on natural reefs, so there will be a certain amount of allelopathy. However, these animals can be maintained together in a certain "stand off" with use of aggressive nutrient export mechanisms (the aforementioned skimming, water changes, and use of chemical filtration media). It's much more ideal to develop a stocking plan that utilizes animals that live together in nature. However, as we often state, this is a closed system that we're talking about. It can be done-and done with some possible success, but it is not ideal. I have seen many successful "garden" reef systems over the years, so I can't say that it's not possible to do this. just not recommended!> As I plan for a big expansion of my system, these are the thoughts that come to mind.  Natural (refugium/Caulerpa/seagrass and/or clams) vs. mechanical (protein skimming).  I currently have both.  Is chemical filtration needed? <I believe that a "natural" approach, with a few technical props (skimming and chemical media) is the best approach for most systems> Are water swaps absolutely mandatory, which would dampen my enthusiasm for a larger tank.  Would removing some of the aggressive corals reduce the allelopathy problems or would the bigger tank mitigate them? <Yes, removing some of the aggressive corals could help, as would reducing the proximity between corals. However, it is still important to change water. I would have to say that it's mandatory! Please understand that it just is not that daunting a task...Small amounts often is not that difficult!> Long email.  Apologies.  Thanks for the time. <My pleasure! These were some excellent, thought-provoking questions that have stimulated many a late-night fish nerd conversation at a MACNA conference! I hope that you will be in this year's MACNA in Louisville so that we can discuss these things in more detail! Good luck! Regards, Scott F>

- Carbon removing trace elements... - I have heard that if you use activated carbon in a filter, that it will remove trace elements.  True or false?? <True and false, it removes some trace elements, most notably iodine, but leaves plenty as well.> I use a Eheim Professional 2 canister filter, which uses a charcoal filter pad in it.  Would this be removing the trace elements I'm adding twice a week?? <Depends on what you're adding. I would only run carbon once a month for 3-4 days or when you notice any tinge of yellow in the water (best seen in a clean white bucket). Have fun! -Kevin> Pat Auburn, NY

Yellow tang... err... tank problem. Dear WWM Crew, Thanx for the quick replies to my previous queries! Anyway, I have 2 more questions...  First one is on Carbon Usage: Here's some background on my 90g: 3 x 2 x 2, with Trickle Wet Dry and Miracle Mud in sump with Caulerpa... so far not many problems, but my water is SERIOUSLY yellow, and worried that my water might have a Huge amount of dissolved organics. Ammonia and Nitrite are both zero. <I'm a huge fan of using protein skimmers on all tanks, regardless of the refugiums or mud filters employed.> I was wondering if using Carbon is alright for my system because... 1. I hear that carbon absorbs trace elements and other useful stuff. If I use Miracle Mud, which is supposed to leach out these useful compounds, wouldn't it be really silly to add carbon to absorb them? <I wouldn't worry about it, it's a much bigger problem for photosynthetic organisms in the tank because the yellowness filters out much of the available light.> 2. Would my Caulerpa crash if there is a sudden drop in Iodine/ other Elements if I use the carbon? <Caulerpa can crash at the drop of a hat, that's why I don't grow or recommend it. If the water parameters change drastically, that can spur a crash, hopefully the carbon won't.> 3. I have a couple of inverts in my tank... Shrooms, Star Polyps, Palythoa, Torch... they've been doing pretty okay for the past 2-3 months without any supplemental feedings and under low light - 2 x 36W PL 50/50. I was beginning to believe that these corals are feeding on the organics in the water... Question is, will this sudden removal of organics be detrimental to my corals? <No way, get that yellowness out of there, the little light that they are receiving is being filtered out by it.> 4. My fishes are doing alright... is there any possibility that a sudden change in water conditions can lead to their demise? <Nope!> Second Question: I currently have a Pyjama Cardinal, Lemonpeel Angel, Flame Angel, Bartlett's Anthias  <My FAVORITE Anthias!>  Lyretail Hog, Regal Tang, Red Sea 4 Line in my tank.  I was hoping to add 2-3 more fish.  So far I would like to get the Royal Gramma... Any recommendations of other fishes which are 'compatible' with my fishes above and some Shrooms, Polyps and LPS? <The royal Gramma should work out, I'd suggest a pair of tank raised neon gobies as well, read all about them in Bob's articles!> Would love a Desjardinii <Would outgrow your tank faster than Caulerpa can crash!> but its never available in my country (Singapore). Thanx for the Help! <Good luck!> PS: Just a bit worried on the matter of carbon because I don't want another system crash... already had 1 minor and 1 major crash... a year ago <Ew, that's no fun, throw in some carbon and let's get this thing clear! -Kevin>

Use of carbon in reef tanks - 4/17/03 Thanks very much, Paul. <You are very welcome.> Would you mind elaborating on the use of carbon most of the time? <Well it is very well documented on various reef sites, a great many books, as well as here on WetWebMedia, but here is my take on it. I advocate the use of carbon in small CORAL reef tanks. (Yes, that is emphasis on corals.) For one main reason - allelopathy (http://www.colostate.edu/Depts/Entomology/courses/en570/papers_1998/lindberg.htm) - the ability for corals to use noxious chemicals (or the use tentacle aggression which I don't believe applies to the use of carbon and only slightly in the term allelopathy) as defense mechanism against encroaching corals or other predators. The allelochemicals produced seem to inhibit the growth and development of other corals in the surrounding area. Not necessarily the only use of noxious chemicals and sweeper tentacles but one that does frequently occur in reef tanks. (some other uses are still unknown)> I'm usually an advocate for not using carbon except when all else fails. What about depletion of major and minor trace elements when using carbon? <Not likely an issue here. Please read this link as it sums it up best (especially the last quarter or so.) http://www.wetwebmedia.com/chemFiltrMar.htm. There are some faq links if you want to see what others are doing or if similar concerns are being raised but overall, I believe with regular water changes, and the continuation of your additive schedule you will not have a problem. Basically, I would use it for maybe two weeks on and two weeks off as this is a nice middle ground to work with. Thanks for the inquiry.> -Chris.  

The color of water I have a nano reef at my office and the water always seems very yellow within a few days of a water change.  What could cause that? Ana M. Saavedra <Likely an accumulation of "organics"... easy to do in small volumes. I encourage you to get in the habit of using a small (a few ounces) or activated carbon in your filter flow path (you can buy a small re-useable Dacron filter bag for changing out) and regularly (weekly, biweekly...) changing this with other routine work on the tank. Bob Fenner>

Water flow and carbon use 3/11/03 Dear Anthony: Thanks for the prompt reply. <Always, welcome> The powerhead (211 GPH) is approx. 1.0' & at a 45 degree angle from the gorgonian. Water params: ------------- 0-5ppm NO3, 0-5ppm NO4, 0ppm NH4, 8.2 - 8.4 PH, 78-80 F TEMP., 4.0 meq ALK,1.025 SPG, 380ppm CA. NO ACTIVATED CARBON. WATER CHANGES: 15% WEEKLY. LIGHT: 2X 55W PC (1 x 10,000K actinic, 1 x 7700K white) <With only 15% water changes weekly, you really need to use carbon regularly to have any chance at maintaining water clarity for optimal light penetration. You might consider an additional power head to oppose the first one to create random turbulent water flow... laminar is harmful or at least not helpful to most corals. All else looks very fine to me :) Anthony >

Questions on carbon Good Day Guru's,       What is your expert opinion on Carbon ?? <Useful... as a chemical filtrant> I've heard various rules of thumb regarding the use of carbon.  I've used in the past Chemi-pure (which I think is the best) and I've used Black Diamond activated carbon.   <Both good products> I do see the differences in my water clarity using carbon.  I have a 140 gal. F/O acrylic tank w/Wet-dry bio and hang-on Protein skimmer.  I usually drop the carbon on top of the pre-filter sponge before hitting the protein skimmer. <Mmm, best to place the carbon about last in your filter flow-path... or at least between a "sandwich" of mechanical filter media> Does activated carbon remove needed bio-media ?? <No> Does Chemi-pure do a more suitable job and last longer ??? <I think so> What do you use ??? <Don't currently use either, but have used both. Please see here re: http://www.wetwebmedia.com/chemFiltrMar.htm and the related Carbon FAQs (linked, in blue at top). Bob Fenner> Any enlightenment is appreciated. Thanks in advance Crew !! Lenny

Reef Husbandry 2/10/03 Anthony- In your reply below you mentioned : "<are you using carbon weekly or at least a large portion monthly? Are your nitrates under 10ppm? etc & your coral are brown likely because they are over fertilized (phosphate and/or nitrate)... Or... they have shed UV reflective proteins because they are not getting enough UV (yellow water, poor skimming, dusty lenses or lamps, old bulbs, etc). There are other possibilities but these are most common. Anthony>" I use carbon one day a week, <there are many theories about how best to apply carbon, but I feel a small amount used continuously is best. Intermittently allows yellowing agents and noxious compounds to ride a roller coaster of "existence" in aquaria with the carbon or/carbon off cycles. Not the least of which are sudden and stressful increases in water clarity which can cause light shock to corals> My bulbs are only three month old & I clean the bulbs once a week, I get good skimming( half a cup a day). <both excellent!> My levels for phosphates are .03 ppm's  and nitrates are 20 ppm's . <yikes... not a crime... but starting to climb> The book that comes with the test kit (Dry Tab Master Test kit) says anything up to 40ppms is fine- Sounds like you are saying that this is too high? <depends on species... and keep in mind that the recommendations are misleading. My recommendation was for 10 ppm of actual nitrate (ionic). Nitrate as read on your test kit is nitrate-nitrogen. Your "actual" nitrate level in the aquarium (ionic nitrogen) is a multiple of 4.4 times the test kit reading. So 10ppm nitrogen (test kit readings) is the same as 44ppm ionic nitrate. So if you are registering 20ppm "nitrate" on your test kit, your actual ionic concentration is 100ppm! That is high nitrate for most any invertebrate. It is also fertilizer for all kinds of algae including the brown zooxanthellae in your coral tissue.> Should I be  using a Nitrate Sponge and how often? <not at all... I don't believe they work well or are a good value even when they do. Simply control your organics. Skim more aggressively, do bigger water changes, use more carbon, refine feeding techniques (never put thawed pack juice from frozen food into the aquarium), etc> Could you also explain yellow water- When I do water changes one a week(8 gallons), I do the water changes into a white 5 gallon bucket and the water does seem a little yellowish but I always thought that was because I just razored the algae off the glass right before I siphoned the water out of the tank. <it really sounds like a simple matter of excess organics... not algae scraping (as evidenced by the high phosphate and nitrate levels)> Please let me know. - Ron <best regards, Anthony>

Even the Italians do it :)  2/6/03 Normally I bother Calfo, now I try this address! <I'm over here too, my friend. Buon giorno from America> What You suggest for Activated  Carbon in a SPS tank... continuous use? 2 days-month use? And for quantity? <yes, my friend.. continuous use in small portions changed weekly for full reef tanks, especially. Perhaps 3-5 ounces per 400l weekly... just an estimate, though. Let the color of the water (yellowing agents) be your guide > Thanks MUCH! Marco, Italy <Ciao m'amico, Anthony>

Using carbon Crew,   Thanks for your response, I will try these suggestions, just one quick question?  I would like to run charcoal <carbon> in my aquarium one week a month or so, what is a good external power filter to use for a 55 gallon 90 lbs live rock?  I do not care bout mechanical purpose, just a cheap easy way of adding carbon.<Since you are just looking for carbon, get a media bag, available at most LFS and follow the instructions on the carbon container for amounts. Don>  Thanks

Fungia and carbon question hey crew, hope all is well with you guys.   <Howdy!> I have a Fungia coral, it is on the bottom  of my 90 gal. reef tank, the other day it was going through these contractions and expelling a reddish, brownish stuff.  Tried to take pictures , we'll see if they turn out.   <awesome... please do share them with us> Anywho... I'm hopping it was either digested food or going through reproduction and not expelling its zooxanthellae.   <easy to tell... digestion is most likely if you have been feeding this very hungry coral 3-5 times weekly or better. Else, little or no food on the bottom of a 24" tank is not a good situation for this weakly zooxanthellate coral. By some estimates, about 30% of its diet cannot be met daily by even the best lighting> My water quality is great and all others are doing well.  The Fungia is doing well also--looks great, its eating minced seafood and swells up at night and moves around a little bit, so I would venture to say what ever it was doing was not a bad thing.   <agreed... all sounds good> Maybe an opinion of yours would be great.   <OK... I think the Pittsburgh Steelers had a fine season all told and they played hard and nobly this past weekend. Kudos to the coach, Tommy Maddox and my favorite- Heinz Ward... Hard working athletes <G>> Also for my 90 gal. reef I'm wondering how much carbon per gallon should I have placed in my sump and how much should I change weekly.  thanks a bunch as always gentlemen..... I would use 2-4 ounces of carbon weekly to start with. See if that is enough to keep all discolorants out of the water (look for yellow in a glass of aquarium water against bright white paper). Add more if necessary. Best regards, Anthony>

Re: carbon particles Happy New Year Crew !! <And to you>      I just replaced my carbon bags down below my tank and apparently I didn't rinse the carbon enough.  This morning I noticed little carbon particles on my coral and Tank decor. (Fish only tank)      Is this anything I should be worried about ?? Looking forward to another insightful year from the crew, <Not too much actual trouble, but unsightly. I encourage you to either give the bags a rinse (in the sink) ahead of use to discount, remove much of the fine material, and/or place some "filter wool" (Dacron) on both sides of the bag in your filter flow path. Bob Fenner> Lenny

Use of Carbon II Thanks for the information. I was changing every 3 weeks when I make my water changes. Is this too long? <For me, yes.> I understood that it lasted about a month? <Likely far less than that. If you want, you could rotate the carbon. Estimate how much you need for your tank and then break that up into four separate bags. Then replace one bag every week. That way there is always some fresh carbon in there and more consistent removal. -Steven Pro>

Use of Carbon I have a 180 gallon reef tank with a 55 gallon refugium and a 30 gallon sump that has a wet/dry and a protein skimmer in it. I have a canister filter on the refugium with Kent reef carbon in it. My question to you is should the carbon be left on 24/7 or just a couple of days a month? <I prefer to use all the time and change if often, using small amounts and changing weekly.> Reading your website FAQ it seems that depending on who is giving the answer it varies. I am looking for clarification since I have heard that running carbon 24/7 will remove the essential elements (KENT Brand) that I am adding weekly. <Carbon, like protein skimming, will remove far more bad than good. I feel the benefits far outweigh any potential downsides.> Thanks for your response, Mike Winston <You are welcome. -Steven Pro>

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

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