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Biofilter... for <"aggressive nutrient uptake"> for <small>
Sponge filter 7/6/15
Cycling; SW 5/6/14
I would like to enquire about this method of cycling a tank. Say I setup a 120 Gallon tank:
* with less than 1 inch of sand.
* some mix live rock and artificial rocks.
* no chiller (temperature is about 29-30 degrees C),
* run bio-pellets,
Run this tank until NO3 is 0 (assuming bio-pellets will do this last bit too)
or 5mg (Assuming this may take 2-3 months)
<Mmm; not this long... likely a few weeks>
Then only start stocking the tank with:
* 2 clown fish & Algae goby (once NO3 is 5mg)
* Yellow tang (a month after 2 clown fish and algae goby and NO3 is within 5mg)
* Sohal tang (a month after 2 clown fish and algae goby and NO3 is within 5mg)
<See WWM re... I would not use this Acanthurus species in this size (small) system... Gets to be very mean/territorial at times>
* Neon Dottyback & Royal Gamma (a month after the last addition and NO3 is within 5mg )
* Flame angel (2 months after the last addition and NO3 is within 5mg )
Will I experience?
* A major nitrogen cycle again and
* Diatom stage
Please advise the flaws of this approach or potential setbacks.
<Should work out fine... Sub something else for the Sohal... perhaps a Ctenochaetus sp.... Thank you for sharing.
Re: cycled WITHOUT a nitrate test?
Belize System Zero Exchange 2/15/13
Cycling a Tank - 10/04/12
New Tank/Skimmer/Sump Set Up 9/26/11
Fishless Cycling 12/17/10
Fishless Cycling 12/17/10
Live Rock Substitute/Denitrification 3/27/10
Skimming during Tank Cycle? -- 01/13/2010
Cycling Large Store Systems 9/29/2009
Re: Cycling Large Store Systems
Nitrogen cycle speeding up 01/17/09 Hello. I am trying to set up a new tank, as I mentioned before, and I am trying to get fishes in it as soon as possible. <You really shouldn't try to rush these things.> So I needed to know if there was a way to speed up the nitrogen cycle for the aquarium. <There are some products that *claim* to do such. They often claim to be bacteria cultures that supposedly speed up the cycling process. However, I doubt they work. I've tried some of them myself and they just don't seem to work. Maybe the advance the cycle a few days, but not by much. There are other products that remove nitrates and nitrites. These might actually slow down the cycle.> If there is please let me know. Thanks a bunch. <I do advise you just try to be patient. Best, Sara M.>
SW Cycling - 3/10/2006 Hello there, <<Hello Tiffani.>> I have a quick question (the set up into it is a bit longer). Well, at least I hope it has a quick answer. I have been cycling my 46 gallon bow front with about 40 lbs of live rock for very close to 4 weeks now. My ammonia level is .25 ppm. In fact, it has been at that level since I began testing the water parameters, which I began 3 days after my initial set-up. I saw the huge spike in nitrites, which has since dropped to 0 and has been there for a little over 2 weeks. My nitrates have been hanging out at 20 ppm as well. They were much higher at one point, but at the 20 ppm level for about 2 weeks. I have done several water changes, as I have read that can lower the nitrate level, however, no such luck. My question is, should I still be registering ammonia if the nitrites are clearly 0? My impression of the whole cycling process was that ammonia is converted into nitrites, then they into nitrates. I just assumed since the nitrite was 0, the ammonia would be as well. My SG has been 1.022 all along. The temperature has been steady at 78-79 degrees. I am wondering if it could be my test kit giving me a false positive on the ammonia. I am using the Marine Lab by Red Sea. <<This could be the issue, of you could be experiencing additional die-off in the live rock. Do buy another brand of test kit, and have your LFS test your water, to ensure the accuracy of the reading. Also, have you checked your source water? Test the water you add to the tank, to see if this is the source of ammonia you are seeing.>> I am anxious to get started with adding some livestock, but patient. <<A virtue in this hobby of ours. You will thank yourself later!>> Thank you in advance for your time and for maintaining such a thorough and wonderful website. It is much appreciated. Sincerely, Tiffani Tobin <<You are quite welcome. Glad to help. Lisa.>> SW Cycling II - 3/12/2006 Thank you very much Lisa. <<You're welcome!>> I will purchase a different test kit and see if I get different results. Not to say that things are not dying off on the LR, but there sure is a lot of life scurrying around on them. I guess having ammonia readings then could mean there is additional die-off. I had not thought about that. Would I then expect to see an increase in nitrites, because I have not over the past 2 weeks? <<It is hard to say. Live rock often changes the typical cycling levels we would expect to see.>> I will be sure to have an LFS test my tank water too. I will also pick up an ammonia test kit for freshwater and see what happens. <<Yes, as your source water may in fact be the issue.>> Thanks again, Tiffani. <<You're welcome again! Lisa.>> SW Cycling III - 3/16/2006 Hello Crew, I guess since the replying back and forth, the initial email has gone off into cyberspace somewhere, but I still have a couple of questions. I will try to sum up things in a Reader's Digest version. I am now cycling for about 4 & 1/2 weeks. I have been registering 0.25 ppm of ammonia for over 2 weeks with no change. Nitrites have been a clear 0 for the same time (I did see the initial gigantic spike in the beginning of the cycling process, with the drop to 0). Nitrates appear to now be a little less than 20 ppm, but not quite 10. Anyway, I was (in a previous email) wondering if it could be my test giving me the false positive on the ammonia. So, I went and bought a different test for ammonia, a dip test into a vial of tank water. I have tested 4 times in the past 3 days and that is registering no ammonia levels. I also purchased a SeaChem Ammonia Alert that suctions inside the aquarium for a constant level of ammonia. That has been in place for 3 days as well, and that also shows no readable ammonia. I just do not know how reliable that is. I, of course, have no intention on relying on that alone in the future. Should I believe that it is actually possible there is no ammonia and my tank may be cycled at this point? <<Yes.>> Two test methods would indicate yes. If there is a problem with My Red Sea Marine Lab test kit for ammonia, do you think it is possible all other results are inaccurate regarding other parameters? <<If ever in doubt, use a secondary test/method.>> Sorry, I think I have bordered on a novel version. <<Not a problem, it helps me remember the original question, when it is not attached.>> I am sorry, one more question. Reading through your site about water for the tank...I want to clarify something if I can. If I allow water (for top off or salted for a water change) to sit in a container with a power head and thermometer for at least a week, does it then NOT NEED a dechlorinator? <<The chlorine will gas off over time, but other harmful substances will remain. I use Prime, by Seachem.>> Thank you so much in advance for your time with this matter. Do you ever just feel like slapping people like me? <<Not at all! Lisa.>>
Lighting after cycle Hello.. excellent website.. Ok I started cycling my 55 gallon reef tank on May 10 and on the third day the ammonia peaked and then started to drop down.. then on the sixth day the nitrite peaked to 5 ppm and then dropped to .50 ppm the next day (what up with the sudden drop?) >>It means you've got bacteria establishing VERY quickly. >I'm cycling with LR and live sand >>Well, THAT would explain the sudden drops! >CPR protein skimmer r2, and I have a built in wet dry filtration.. it seems my tank is almost done cycling. >>Yep. Once ammonia and nitrite are zero, and nitrate begins coming up, I'd call it cycled, too. >Now my question is how long can I go w/out light or can I because I ordered my pc lighting system through the internet and it still hasn't arrived.. (it should have been delivered already) and now I'm starting to get worried! >>Unless you have photosynthetic specimens (and at this stage you better not!), there is absolutely no need for lighting. >What should I do in this situation? >>Call the company you bought your lights from, and call the shipper, and be a squeaky wheel. (They've probably arrived by now.) >One more question.. my substrate is 1 1/2 inches and I want to add like an inch more.. can I add live sand during or after the cycle and will it mess with the cycle or the wet dry filter, or should I wait till all the sand reach the bottom before I get the filter starting again? >>Won't do a thing to the w/d, I'd add it to the live sand now, in bits, over sections of the sand, say, 1/3 every few days. Test to see if it's causing any spikes (though I doubt it will). You can seed it a little faster by using Bio-Spira then adding some fish food or raw shrimp to the tank to cause another nitrogenous spike. >I'm planning to add 20 more lbs... thanks your guys opinion means a lot to me.. thanks again.. James >>And there you have it. All should be going well at this point. Marina
Help With Cycling Fishless for Newbie >Dear Bob, >>Hello Nahid, Marina is answering for Bob today. >I am a new beginner for marine aquarium. Sir I like to know that I have been never success in keeping a marine aquarium. Sir very often when I mix the marine salts, the nitrite level goes up and all of a sudden comes below. >>I am not familiar with sea salt mixes that can cause nitrite levels to go up on their own. However, I believe you need to become more schooled on nitrification. This is where one kind of bacteria "eats" ammonia, and makes it into nitrite, then anther kind of bacteria "eats" the nitrite and makes it nitrate. >What you want to see will go something like this (when you test) 1: high ammonia 2: high nitrite 3: ammonia begins to drop 4: nitrite begins to drop and nitrate begins to rise 5: nitrite drops and you get higher nitrate readings >>High nitrate are then controlled in several ways, simplest for beginners is water changes. >But when I started adding fishes, they died one by one. >>You may be adding fishes that are too big, or you are adding them too fast and they die of the high ammonia and/or nitrite. This is not uncommon. >But from books I read to use ammonium chloride during the time of cycling and amount of ammonium chloride is not mentioned to be used. Can you help me out what quantity of ammonium chloride to be used per gallon. I will be very much thankful. Yours sincerely, Nahid , India. >>Better yet, and much easier for you, is to put a piece of raw shrimp, crab, or fish (some fresh seafood) into the tank and allow it to rot (many people like to tie it up in a piece of women's nylon hose or a piece of white cotton cloth). Then, after two or three days you will begin to test the water. Watch for the rising and falling as I've outlined above. When you have ZERO ammonia and nitrite, you will know you have bred cultures of nitrifying bacteria. Then, when you add your fish, ONLY add one at a time, and we do encourage quarantine (search our Google bar for "quarantine"). I must note that I do not know the size of your tank, nor your filtration, so I cannot recommend what fish to keep, nor in what order to introduce them. These are very important considerations as well. I hope this is helpful information. Marina
Patience Is The Most Important Additive! Hi Scott <Hi there!> I had my water tested a few days ago and here are the readings Ammonia : 10-20 Nitrate : 0-10 Nitrite - 0.1-0.25 PH - around about 8 <Sounds like a normal tank start-up/cycle. Just hang in there and be patient as the tank cycles...> Please comment on my readings. Looking at these readings how much longer do u think I should wait before I could possibly add fish. <Hard to say, as every tank cycles differently; it can take as little as 10 days, or as much as 3 weeks. Unfortunately, nature is one of those things that we impatient humans cannot rush! It will not be safe to add fishes until the ammonia and nitrite return to undetectable levels.> I have cut down the water changes to once a week and I was thinking of testing again this coming w'end and the next w'end. Do u think another 2 weeks will do? <Don't do any more water changes until the tank finishes cycling. At this point- less is more...Do nothing...It's important not to mess with things now!> Thanks Again Regards Ziad Limbada <You're right where you want to be, Ziad. Just be patient, monitor the water parameters every several days, and things should continue just fine! Good luck! Regards, Scott F>
Saltwater tank cycling... >Greetings! >>And salutations, Marina this morning. >I have been reading your website religiously for the last two weeks and I am amazed at the time and effort that the staff puts into answering readers' questions. >>He.. hoo are WE! >I am a newbie to the saltwater world, and recently my roommates and I set up a 50 gallon (4 sq ft surface area) tank. The substrate is 2/3 crushed shell with a "mini-beach" of live sand (3 inches deep) taking up the other third of the aquarium. There are approximately 20 lbs of the branch-style live rock with purple, red, and white coralline algae. We have a Berlin air lift protein skimmer (with prodigious skimmate produced), a 360 gph paddle-wheel-and-activated charcoal filter, and a supplemental air stone to provide additional aeration and water movement. Our tank has been up and running for two weeks now with a four very small fish that are active, colorful, feeding, and healthy-looking. We also have 5 hermit crabs, and two snails of the Turbo persuasion. Our nitrite level peaked, and nitrate is now at 0.2. However, in the last several days, our nitrite has begun to rise again and our tank has a lush covering of brown algae. After reading your FAQs, I understand that this is probably of diatomaceous origin. I suspect that we are overfeeding and keeping our lights on too long, and we have recently taken measures to control this. I was wondering: Is algae grown indicative of completion of a nitrite/nitrate cycling, or does it comprise its own cycle? >>No, algal growth is indicative of excess nutrients, light being one of them. Nitrate is a nutrient, as are phosphates, and dissolved organic compounds (DOC's). >Will the oxygen saturation of the water decrease as these brown algae cycle out? >>Yes, but with the water movement you describe it would be negligible. >Is it now safe to perform a water change of 10-20%? >>With the peaks you describe, and assuming you haven't made any water changes, I would suggest a 50% change, with no vacuuming or disturbance of the substrata. Do know that the shell substrate *will* accumulate detritus. I recommend a serpent star or two to help with this. Also, once the tank is well on its way, I recommend vacuuming the substrate of shell with each water change--1/3 at a time. >Aside from stopping the overfeeding/shortening the light exposure, are there any other means of controlling the algae this early in our tank's life? >>You could try something like a tuxedo urchin, though they're more known for helping eradicate hair algae. I could suggest abalone, but they are voracious feeders of the algae. Let the diatom bloom do what lemmings do, it will eventually starve itself out. If you are not living in a state with restrictions on Caulerpa (in California we are allowed NO feathery fronded species), then that can be used quite effectively as a natural means of outcompeting the diatoms for nutrients. >What types of algae-controlling organisms will not compete with the lawnmower (Jeweled) blenny that we have our eyes on? >>See above. Do hope this helps! Best of luck McGregor. Marina
When is cycling finished? Steven, <David Dowless answering this evening> Sorry to be such a pest, but I'm just a newbie to the Saltwater tanks and there's soooo much to learn. <And unfortunately...no one will ever be able to learn all of it!> As for my tank equipment in addition to the UGF, I also have a BioWheel and 10lbs. of live rock. Will my nitrates still continue to be high? <The UGF and BioWheel will both work to create nitrates. I would add more live rock and a protein skimmer.> It's only a 20gal. tank, and I'm obsessive about topping off water, making sure the temp is right, etc. It's been up and running for 6 weeks now, and I thought the initial "cycle" would be done by now. Am I wrong? <No way to tell unless you've been running ammonia, nitrite and nitrate tests. THESE TESTS ARE A NECESSITY if you want to be successful in this hobby. There is no hard and fast rule about cycling although I would guess your tank should be about finished. Test the water. When you finally begin to add fish do it very slowly, one at a time and feed lightly> I know I have to keep up with the water changes, but I thought that since the tank is new and still cycling that I shouldn't do any changes in the water until all the parameters were within normal limits. I've spent hours and hours at this website (usually late night) and sometimes the more I read, the more confused I become. Everybody you talk to seems to have a different opinion so that's why I'm writing again. Hope you don't mind. <I don't exactly agree about this last point. There are differing opinions on the best lighting, the best filtration, fish that are compatible etc. But some things in this hobby are known as fact. For example...the cycling event that you speak of has been well documented for many decades and we all know there is no preset time for cycling to stop. The event is ammonia, then nitrite then nitrate. The CMA book (by Fenner) shows a time line of 36-48 days...but there are no guarantees. Patience my friend> I just want to make sure that I'm doing everything right. <Knowledge is the key to success in this hobby. You're on the right track. Keep reading and learning. Eventually you will have enough "opinions" that you will be able to decide what makes sense for yourself> I also have one more quick (promise) question for you. Should I wait to add some new additions (in particular a cleaner shrimp) until my nitrates drop? <My friend you need to keep reading. Shrimps of any kind would never be my first choice of critter in a brand new tank. They're very sensitive to water quality> Thanks bunches. <It's an honor to serve. David Dowless> Maureen
Trigger and ammonia Bob, <Rob> After about 1 week now, the ammonia level in the new tank is near 1ppm and the nitrite level is at about 0.2ppm. I am planning on doing about a 15 to 20% water change tomorrow. <I would wait on this... unless there is some compelling reason... the change will too-likely produce a "metabolic check" on your nitrifying microbes... forestalling the establishment of nitrogen cycling... Wait till both ammonia and nitrite are zero> I have not turned on the skimmers in the new tank (b/c I was advised to leave them off during the first month). <Mmm, I advise you to turn on your skimmer/s> Given the current situation, would it be wise to turn them on to remove some of the pollutants from the water? <Yes> Thanks again for all your help. <You're welcome. Bob Fenner> Rob Stein.
Question About Tank Cycling Hi Bob, I have a question about the cycling of my newly setup 125 gallon saltwater tank which I will use for fish only. I have never had a saltwater tank before, so if some of these questions sound off the wall, sorry. Here's my situation: I purchased this tank used from a private individual whom previously had it setup as a freshwater tank (but also had it setup as a reef tank before that). He drained it and tore it down just two days before I purchased it. With it he gave me a huge Tupperware container full of the gravel mixture that he already had in it (it was a 50/50 mixture of gravel and crushed coral). I took it home and set it up the next day using most of his gravel plus 30lbs of new crushed coral that I rinsed thoroughly. I added one damsel the next day, and then 14 more one week later. <Fourteen? Ten plus four?> It has now been one week since I have added the 14 damsels to the tank, or 2 weeks since the first damsel was introduced. I have tested the water every day since I added the 14 damsels, and I continually get the following results: pH - 8.2, Ammonia - .25, Nitrite - .5, Nitrate - 20. I have been very confused about the readings because everything I have read about nitrogen cycling says that your ammonia should shoot clear in the first 10 days then drop to 0, followed by a spike in nitrites then drop to 0, followed by an increase in Nitrates. <Nah... many variations on the theme here. Your readings are likely accurate> I have begun to wonder whether or not my tank has cycled already? <Some> I read something that said to speed up your cycling you could go to a pet store and ask for a cup of gravel out of an already established tank. Well, after reading that I thought about it and I did put in approximately 75-100lbs of gravel mixture out of an established tank. Could this be the reason? Is it possible it has already cycled? <Yes, and partially cycled> Would it matter that the gravel mixture came out of a freshwater tank and not a saltwater tank? <Oh yes... different bacteria involved... and a bit of a "population check" (caesura, slow down) in the big move> The gravel did sit in a Tupperware container for 2-3 days (there was a lot of moisture in the container). Would this kill the bacteria? <A good deal of them, yes> Two days ago I fed the fish more than the usual amount because I read that that would generate more ammonia than normal. I then tested the tank the next day (yesterday) and the ammonia was still at .25. Well, what do you think? I am in dire need of a professional opinion. I want to buy some different fish, but I want to be sure that I am not going to kill them by putting them in too soon. Do you think it is safe or should I wait a little longer? <Do wait... a few weeks more till the ammonia and nitrite have been zero for a while. Please read here: http://www.wetwebmedia.com/estbiofiltmar.htm and the FAQs links there> Now that I got my main question out of the way, I have a few more that aren't as important. The lady that runs the only pet shop around here (only one within 220 miles) won't buy damsels back. So, I'm wondering if it will be safe to add other fish to the damsels or if I should get rid of some or all of the damsels first. <Depends on what species they are, your desires> I would like to keep them if I could since they cost me 6.95 each, but I will give them away if I have to (or maybe make a quarantine tank and put them in there for a while?). I plan to add some clowns and tangs or something. What do you think? <That you need to think, study, develop a stocking plan... read through WetWebMedia.com here> What fish would you recommend. I really like the maroon clown because it looks awesome, but I understand that it is very aggressive and would make it difficult to add smaller fish later. Is this correct? Also, I read about the need to give new fish a freshwater bath before adding them to a new tank. I do not have any other tanks, so I am wondering how I should go about this. Is it okay to put sink water in a pitcher and just add water conditioner to get rid of the chlorine? Will it work to use this as a 10 minute freshwater bath or do I need something more elaborate? <Acclimation protocols, others experiences are detailed on WWM> Well, that is all I can think of for now. I did not intend for my questions to be so long, sorry about that. Any advise you can give me about my situations will be greatly appreciated. Thanks in advance for your response and thank you for your wonderful website! It has been a huge help! -Scott <And will be more so with your help. Be chatting my friend. Bob Fenner>
Power filters and protein skimmers Bob, How are you doing? <Fine, you?> I am new to marine aquariums. I have a 75 gal tank that I am setting up to be a marine tank. I have 100 lbs of Live Rock, and 80 lbs of Live Sand. I would like to use HOT filters and skimmers to keep the cost down. I currently have a TetraTec PF500 power filter and a RedSea Prizm protein skimmer. I wanted to know what you thought about these 2 products, if you had reviewed them and how do these 2 products compare with similar products? <Fine products. Very good for what they're designed for> I had originally filled the tank and then added the uncured Fiji live rock about 3 weeks ago. I then read that Tetra had a new power filter to replace the Whisper 5 that I got with the tank, so I exchanged the original filter with the TetraTec. I then tested the water and the Nitrite and Nitrate readings were very high. So I did about a 80% water change 2 days ago and installed both filters (TetraTec and Prizm). <... eighty percent is way too much... better to do smaller changes... wait off on all during your "run in period". Please read over the set-up, establishing biological filtration sections on the marine index on WetWebMedia.com here> I was going to wait about a week and test the water again before I start putting fish or invertebrates into water. <Mmm, wait about a week after your nitrites go to zero... or more to try a hardy invertebrate> I read your book and thought it was wonderful. Are there any monthly magazines that you would recommend so I can keep up with the technology changes and other interesting news about marine animals for my tank? <Yes... as a matter of fact all three of the national monthlies: AFM, FAMA, TFH... their URLs et al. from there can be found: http://www.wetwebmedia.com/links.htm in the middle top of our links page. Bob Fenner> Thank you, Tom Schumacher
Cycling Question Greetings, I wanted to know about a cycling issue. I put about 160lbs of Fiji rock into my 125 about 2 weeks ago. It was curing at the LFS for I am not sure how long, maybe a week or two. I have been running a protein skimmer for about 10 days and using activated carbon. I never really was able to read ammonia, but about 5 days ago, the nitrites were around 5 and nitrates over 20. Two days ago, the ammonia was still 0, the nitrites were around .1 and the nitrates were around 15. Today the nitrites are at .01 (Salifert low level test) and the Nitrates are at 2-5 (Salifert). I also have a DSB with about 100lbs of aragonite and 60lbs of live sand. It seems that the live rock has cured as indicated by the low levels of nitrites. Question is when should I begin adding inhabitants? <Give it a week just to be sure your water quality is stable.> I was thinking of first adding a cleanup crew, then a few Percs, then a few soft corals over the next month or two. When would you suggest adding the snails, crabs, and other inverts for the cleanup crew? <Go ahead and add them first to help control algae.> How long after that would you add the Percs? <The longer you wait the more copepods, amphipods, mysids, etc. you will have scurrying around your tank. A month would be fine, but longer is better for the diversity and population of infauna. Thanks! Adam <You are welcome. -Steven Pro>
Use of Ammo-lock and other Ammonia detoxifiers Hello Mr. Fenner! <Howdy> It's been a while since I've emailed you, but that is attributable to the fact that I use your book, "The Conscientious Marine Aquarist" as my marine tank bible. It answers the vast majority of my questions! However, I'm in the midst of a debate that I'm having a hard time settling. <Perhaps there is no such settlement to be had> Today I've got a question on someone else's behalf regarding the use of Ammonia detoxifiers, such as Ammo-lock. This person setup their 75 gallon aquarium and added fish prior to cycling (I've had great success with fishless cycling on my tanks). They were told by their LFS that the live rock and live sand would not be sufficient to cycle the tank, and that they needed to add fish. <Mmm, I do disagree... the LR, LS are fine on their own> Well, they did, the ammonia spiked, the fish began dying, and the LFS person told them to use Ammo-lock. They did this and, now, after seeing a spike in Nitrites and a gradual rise in Nitrates, they're experiencing a second, HEAVY ammonia spike. <To be expected... the product by Aquarium Pharmaceuticals is fine for what it is intended for... but this does NOT include forestalling the establishment of biological cycling> Now, I understand that Ammo-lock is supposed to convert NH3 to NH4, which is less toxic to fish, but that it should not prevent the accumulation of Ammonia in the tank. <Actually... this product does not do this> I also understand that it will skew test results. <Can, yes, some types of tests> Personally, I've always been of the opinion that, chemically speaking, less is more, and that water changes should be used instead of chemicals, but I understand that others feel differently. My advice to this person was to bring the remaining live fish back to the LFS (no hospital tank setup) and continue cycling the tank in a fishless manner. They told me that Ammo-Lock does NOTHING to inhibit the cycling process. <Not so... the ammonia present is chemically bound-up, hence the group of nitrifying bacteria populations that "consume" such die off... and must need "re-grow" to convert newly formed/forming ammonia to nitrite, supplying this to other microorganisms that convert this in turn to nitrate... A simplistic model, but if "A" is necessary for "X" to make "B", and "A" is made unavailable then "Y" that relies on "X" dies off along with "X"...> So, my question is -- do Ammonia detoxifiers inhibit the cycling of a tank? <Most, by numbers of products, popularity... actually do forestall the establishment of biological cycling> What EXACTLY is their purpose and should they be used in situations such as these? <Purpose? Let's see... mainly useful in dire "emergency" situations (too much bio-load being added too quickly, loss of biological filtration integrity in a compromised setting (e.g. treatment, quarantine tanks)... NOT in systems that have yet to fully cycle> I've always been under the impressions that nothing like this should be used while a tank has been cycling (I prefer never to use these things, no matter what the situation, but that's me). Any advice that you could give on this topic would be greatly appreciated! <We are of the same impression, belief set here.> Grateful as always! Deb Colella (A humble aquarist who strives to be as adept at this hobby as you!) <You humble me my friend. Bob Fenner, who apologizes for the delayed response. Have been out of the country> Deborah Colella