Please visit our Sponsors
FAQs on Natural Seawater Use

Related Articles: Synthetic or Natural Seawater, Saltwater Impressions (Synthetics Review) By Steven Pro, Specific Gravity,  Water Changes/ChangingpH, Alkalinity, Marine Alkalinity

Related FAQs: Seawater 1, Seawater 2, Seawater 3, Seawater 4, Seawater 5, Seawater 6, & FAQs on Mixing, Supplementing, Storing, Moving, Physical/Chemical Troubleshooting/Fixing... By Make/Manufacturer: Synthetics: Aquarium Systems (Instant Ocean, Reef Crystals), Aquacraft (Marine Environments, BioSea...), Central Garden (Oceanic), Kent Marine (SeaSalt), Red Sea (Red Sea Salt, Coral Pro Salt), SeaChem Marine (Marine Salt, Reef Salt), Energy Savers (Coralife), Tropic Marin, Other Brands... About Buying Pre-mixed Seawater, About  Synthetics Manufacturers Advertising Claims...  Spg 1, Treating Tapwater For Marine Aquarium Use, Reverse Osmosis Filtration 

I was wondering if its okay to use this directly from the ocean for water changes?
<I wouldn't... better to develop, adhere to a regular protocol of collection, storage, treatment ahead of use...>

pH. Natural SW coll., use      2/8/13
Hi Crew, This is really feedback for your readers. Having read over the years that pH should be 8.2 to 8.4 I am surprised that the seawater where I stay on the Andaman Ocean (Indian Ocean) is 8.0
<Collected where? You may have to get a bit offshore, the open sea. This being stated, 8.0 isn't too low for most all uses; as long as there is sufficient alkalinity/buffering capacity to insure against drastic drops>
I was concerned that my tank which is inverts and fish is too low. I have checked it with two test kits, API and Tetra. The water I take has delicate fish like the Moorish Idol nearby
<Not delicate in the wild>
 and I don't take it if there has been any rain in the last few days leading to potential runoff from the land and always at night in case swimmers etc have used suncream etc and away from any small fishing boats.
I hope this helps your readers. Regards, Adam.
<Thank you for sharing. Bob Fenner>

Contaminated water... SW losses det.     3/15/12
Hi, My fish have died but I am unsure if the cause is a disease or contaminated water. The water comes from the sea and there are many Butterflyfish etc nearby but I am wondering if as I collected the water there was some contaminate which would disperse and not harm the fish as it was only there a short time.
<Mmm, could be... the containers you're using to retrieve and store the water are safe, not suspect?>
 The signs of the disease/contaminate are blotchy skin which then get a lot worse until the whole body is washed out. The reason I do not think it is a disease is that there is no increase in breathing rate even before death.
Could any contaminate cause these signs or do you think it is a disease.
The fish die within about a week. Regards, Adam.
<I'd try to eliminate the contamination possibility first here... By collecting water a bit further away from human-use areas, storing it for a few weeks. Have you read here: http://www.wetwebmedia.com/seawater.htm
and the linked files above? Do so. Bob Fenner>

The proper steps to prepare natural seawater   5/26/11
Thanks for being such a great resource. I was hoping you could clarify the FAQs on the subject of "the proper steps to prepare natural seawater".
I realize you are a proponent of synthetic and I have read all your stated reasons but what if I just want/ or need to make it work?
<Natural water can indeed work of course... and may be the more economic way to go...>
I've combed through the FAQs and I've read a lot of info on switching to synthetic, and the reasons why (the woes of natural water users) but not much on how to use raw water and how to make it work right. I managed to pick up a tidbit in there about chlorine (for what I'm guessing 24hrs) then decanting the water on top (no mention of how close to bottom of holding tank you can go).
<An inch or two, depending on how much "mulm" you detect>
Then once the chlorine is gone (another 24hrs with proper aeration?)
<Best to treat w/ "Hypo" (Sodium Thiosulfate) or other such commercial or not dechlorinator>
you can use it safely.
Any thing else I should do, specifically to prevent introducing pathogens/parasites?
<Is posted...: http://wetwebmedia.com/seah2onatural.htm
Most are easily killed, made very weak by storing new water in the dark for a couple of weeks ahead of use, some folks run mechanical (esp. DE) filters on such water, even moving it via such... others employ UV continuously>
I have observed both crypt and some kind of parasitic copepod (had 2 clear flagella hanging off of anchor point) on fins in a few local tanks.
Any tips (excluding switching to synthetic)?
<And here: http://wetwebmedia.com/seah2onatural.htm
The water source itself is already very clear, tests good, and is relatively stable.
Thank you for your thoughts.
<There are a few trade offs in using natural vs. synthetic... the former does have more risk (in general) of pests, parasites and more pollution... but all these but the need for more frequent change-out or addition of supplements can be overcome w/ careful, consistent treatment and handling.
It is not lost on me however that almost all modern/large public aquaria (e.g. the Georgia), use synthetic, despite the cost. Bob Fenner>

Re: The proper steps to prepare natural seawater 5/27/2011
Hello again!
Thank you for such a quick response!
<Welcome Erik>
Seems pretty straight forward.
I have a few follow up questions.
What type of chlorine concentrations are we talking about here?
<A few ppm... as you likely are aware, most gets converted to chloride pretty quickly... 5-10 ppm is fine>
Would seem practical to use the least amount of chlorine needed so to also use the least amount of "hypo" to get rid of it.
<Ah yes>
Does my time frame sound ok? Even with using hypo?
Thank you again for all of your help.
<And you for your participation. BobF>

Switching From Natural To Synthetic 7/27/09
Hello, thanks in advance for your invaluable advice!
<You're welcome.>
I have a question regarding the classic synthetic vs. natural seawater argument...I've been using Catalina water for about three years now (since I set up my reef), and I have decided to switch to synthetic, as I hear the horror stories about introducing pollutants and parasites to my system. I have also grown tired of treating seawater to ensure it is safe.
I would of course match the pH, Alk, temp and salinity before adding either one, but I was wondering if it is safe to take the cold-turkey approach, (to suddenly start using synthetic water instead of natural water with my future water changes)? Is it possible to shock the system by suddenly switching?
<Doing this with partial water changes should cause no problems.>
Thanks so much for your help. I appreciate it, and I'm sure my tank inhabitants will as well.
<You're welcome. James (Salty Dog)>

Water changes with local H2O, Natural Seawater -- 07/14/08 Hi gang, <Hello> Hopefully, a quick question: I have a 120G FOWLR with the following livestock: Six Bar Angel Niger Trigger Maroon clown 6 Blue/ green chromis 8 turbo snails Red Filipino Hermit crab I have the good fortune to live in Tampa, FL near the Gulf of Mexico. My friends have a boat and on a recent weekend trip, I decided to get a small sample of the gulf water to test. I tested the sample and got the following results: pH - 8.4 NO3- 0 NO2- 0 NH3- 0 CA 500 KH- 7 I do a 25% water change in my aquarium about every 3-4 weeks with water I purchase from my local fish store. With these readings, do you think I can use gulf water to do my water changes? I am trying to grow some coralline in my tank, so I realize I will likely have to add buffer to get the KH up, but... Just wondering if this is a good or bad idea. Seems like a nice way to save some money. What do you recommend? Thanks for your help. Rich in Tampa <With the cost of gas I'm guessing the saving go quick. In my opinion there is more downside than upside in using NSW, the chance of introducing pollution, parasites, and unknown variables outweighs the cost savings. All quality marine salt mixes will have basically everything you need, so I don't see much downside to using them. If you do decide to go this route I suggest following Martin Moe's route of using chlorine to sterilize the water before use. See here for more http://www.wetwebmedia.com/seawater.htm .> <Chris>

Re: Water changes with local H2O, Natural Seawater 7/14/08 Thanks for the quick reply, Chris. <Welcome> I figured there was some risk involved. We tend to get red tide every now and then too, so you never know. <Yep, that's the issue really.> If I were to invest in a RO/DI system, would I simply add the correct salt mix to make a proper water change mixture without any other additives? <I would add buffer as well, otherwise that is it.> <Chris> Re: Water changes with local H2O, Natural Seawater 7/14/08 I think making up my own synthetic H2O is the smartest plan. <Agreed> I just have to get an RO/ DI system now. <Several good ones out there.> I was dropping $60+ every other week in saltwater alone and it was starting to add up. <Wow, I bet.> I surmise that gassing up the boat to get water would prove to be pretty expensive too. Although, the trips were for pleasure and I figured while out there, we might as well haul in some free H2O. <Why ruin a nice afternoon by hauling buckets of water around, better to haul buckets full of ice and beer.> No need to introduce some parasite to my aquarium. <Yep> Thanks again. <Welcome> <Chris>

Sea Water Filtration, naturally   03/15/2008 How does natural sea water gets filtered in nature? I've been doing a lot of research to no avail. It is for my godson school project. Any advice will be greatly appreciated. Thanks in advance. <Wow, what a loaded question! It depends somewhat on what you mean by "filtered." The compounds which we aquarists call "nutrients" (nitrates, phosphates, etc.) are largely filtered out by organisms (algae for one). They are also filtered by benthic ecosystems... not too unlike large scale versions of our deep sand beds. But how in depth an answer are you looking for? There are literally whole text books written on this question. You might want to start here: http://www.epa.gov/bioindicators/aquatic/marine.html> José M. Rivera <Best, Sara M.>

Synthetic vs. Natural Sea Water 1/8/08   Salty's go I was looking through your threads and couldn't find the answer to this question, sorry if it was asked already. I was wondering if you can mix synthetic sea salt with natural sea salt? If I were to do a water change with a store bought brand of natural sea salt instead of the synthetic that has already been established in my tank, would there be any issues and if so what? Also what if I were to decide to take a bucket of natural sea water from the ocean prepare it properly and add it to my established system that has been using synthetic. Any issues there? Thank you for your time and patients. <Am not a doctor, have no patients, but I do have patience:) Joe, read here and related articles/FAQs and I think you will find what you are looking for. http://www.wetwebmedia.com/seawater.htm James (Salty Dog)> Joe

Salt mixing 01/08/2008   Andrew's take I was looking through your threads and couldn't find the answer to this question, sorry if it was asked already. <<Hello, Andrew here>> I was wondering if you can mix synthetic sea salt with natural sea salt? If I were to do a water change with a store bought brand of natural sea salt instead of the synthetic that has already been established in my tank, would there be any issues and if so what? Also what if I were to decide to take a bucket of natural sea water from the ocean prepare it properly and add it to my established system that has been using synthetic. Any issues there? Thank you for your time and patients. <<Not always good practice to use saltwater direct from the ocean as you do not know what is going to be introduced into your aquarium. Your tank inhabitants will get all they need from using a good synthetic salt brand. If natural saltwater is your chosen route, then I would suggest the water be conditioned before adding to you aquarium. see http://www.wetwebmedia.com/seawater.htm >> Joe. <<Thanks for the questions, A Nixon>>

Natural Saltwater (from sea) Startup   4/4/07 Hi, <Morning> I live on the coast in south Florida and I am starting up a 120 gallon tank.  I have a few unorthodox questions that I thought you might enjoy. <Okay> 1)  I would like to fill my tank with water directly from my beach.  I have read a number of articles on this, most are either dead against the idea or think it is a good idea. <Mmm, can be a savings of time, money... and good exercise... if the water is relatively clean... But can/does introduce the possibility of introduction of the "three P's"... Pests, Parasites, Pollution... and natural water does not "last" as long/much as synthetics... Most all public aquariums, and all modern ones use the latter... And we will at a new emplacement here in Hawai'i> Facts:  there is a very healthy reef just a mile down the beach, no industry in the area, very low boat traffic, and no streams or estuaries anywhere near by.  I plan to fill the tank over a few hours and then add live rock.  What do you think?  I'm I crazy? <Heeeee! Not re the water here at least... as stated, there are folks, reasons for using NSW... but I do encourage you to at least to adopt/adapt a strict storage, treatment protocol... as presented on WWM... ahead of use> 2)  This one is even stranger.  Since I live on a barrier island, the intracoastal waterway is across the street.  I've noticed while fishing there some very nice algae covered live rock.  Can I use some of this to seed my dead live rock? <You could> The algae growth looks very healthy (very ugly), so I thought it would go nicely in the sump.  I think I will buy live rock to put in the tank.  What do you think?  Am I crazy? <Again... undesirables will be introduced... You'll see in time> Any help would be of great benefit!! Craig <In a number of years, many such trials, you will very likely find yourself switching to phony seawater... for the rationale presented... on WWM... Bob Fenner>

Re: Natural Saltwater (from sea) Startup... abuse, using WWM - 04/04/2007 Thanks for the advice Bob.  I think I will start the tank by having it filled professionally.  I will have to ask them what they will be using. I can't think of another way to get that amount of clean water here without using tap water, which I'm told is not very good.  Is that an option? <Please read here: http://wetwebmedia.com/seawater.htm and the linked files above> I would like to use NSW for changes so I was interested in the details of preparing this water. <... posted>   I've read that some advocate a little bleach, to kill off the meanies.  How much should I add per gallon, and once the water has been in the dark for a couple of weeks, do I need to dechlorinate? Also, should the containers be sealed, or open so the chlorine gas can escape? <No worries re this... complexes to non-gas residual> Regarding live rock, I have a very large volume of old reef (I found it scattered around the property for decoration).  It is very nice rock, full of holes and old coral growth.  What is the best way to seed this rock? <.... Please. Learn to/use the indices, search tool: http://wetwebmedia.com/clnornart.htm and the...> Are there mixes, or should I just let the live rock I buy spread? <... also...> Thanks so much for your help! Craig <BobF>

Thoughts on using natural water.   2/22/07 In the next couple of months I'm going to be moving to a place on the water (intercoastal Gulf of Mexico, St. Petersburg area). I was wondering if there are major drawbacks to pumping water from the backyard straight through a tank. <Mmm, yep... all sorts... three categories: pests, parasites, pollution... All covered on WWM> I was thinking of keeping a tank stocked with local species, basically whatever can be caught under the dock. <Oh, this is a further mitigating factor...> I'm thinking it would be a cool way to have a fairly large tank with a little less cost and maintenance than a more traditional setup. <A worthwhile endeavour, yes> Would I need any type of filtration or would the right amount of flow do the job for me. <Mmm... yes... best to at least store said water in the dark for a couple of weeks ahead of use...> In your opinion, (assuming my collection is in accordance with local laws) is this irresponsible toward the environment? <Mmm, IMO, is not... now, overpopulation, Hummers (the cars... careful here), pre-emptive invasions/"wars"... BobF>

Natural Saltwater Treatment - 02/01/06 Dear Eric <<Akila>> Thanks for the advice again and again. <<Is why I'm here my friend.  I do hope it has been useful.>> You seem stressed out with all your work? <<Mmm, a bit...yes.>> Do you run your own aquarium shop?  Where is the shop located? <<Gosh no!  I'm only working 65 hours a week...not 85 hours a week <grin>.>> Sorry to bother you but I need to explain you something and get some advice. <<Is what I do...>> So here it goes*| In Sri Lanka it's impossible to find marine salt. <<Pity...though I'm sure shipping charges would be "killer.">> This is because aquarists directly use saltwater from the sea as it is a very easy procedure here in Sri Lanka as the beaches are easy to reach in the city of Colombo (capital of Sri Lanka. It has the most beautiful beaches. You should visit here). <<God willing and the creeks don't rise...maybe someday...>> So I buy saltwater from LFS and pump it into my tank.  Because of this I am not sure whether there are any parasites in the water. What do you think? <<I think this is a valid concern and a very real hazard if the water has not been properly "treated.">> Is there anyway I can sterilize the water before I add fish? <<Certainly.  Add a small amount of bleach, stir and let set for a bit, decant the clean water above what has fallen to the bottom of the container to another (dark/covered) container and aerate until use.  Have a look at this article and follow the links for more info:   http://www.wetwebmedia.com/seawater.htm >> Do you think using copper is a good idea? <<No, I don't...many fish are sensitive to copper...and I don't have to tell you what happens when it is misused, eh.>> Now my water is running for about 1 A 1/2 weeks and I see those small white copepods are running around on the glass at night.  Is this a sign of good water quality? <<Maybe...but more a sign of a lack of predators me thinks.>> I think those creatures are in my tank because I use direct sea water, right? <<More likely introduced on/in your live rock.>> In my quarantine tank (40G) I have 2 Damsels and a Sebae Clown fish for a week now.  I am trying to quarantine them for at least a month until my main tank is ready. <<Excellent!>> Three days back I saw some small white spots on my clown but only about 4 or 5 white spots (not like sugar coated like before) and they are not increasing in size or quantity.  And the clown seems to be in fine health.  He eats and swims fine.  The damsels show no signs at all.  What do you think these are? <<Maybe Ick, maybe sand grains.  Keep a close watch and treat if the situation worsens.>> I make 10% water changes every other day with direct sea water. <<Very important this water is treated as outlined.>> Do you think it's enough? <<If this keeps your nitrates below 30, yes...if not...increase the percentage/frequency.>> Oh I also dipped the fish in freshwater with Methylene Blue before putting them in the QT. <<This goes a long way towards prevention...very glad to see some of this is get through to you my friend.>> Do you think I should treat my clown with copper sulfate in the QT?  Or lower my gravity to around 0.0010 (putting A 1/2 freshwater and A 1/2 direct sea water to the QT)? <<I would do neither unless the clowns condition worsens...and then only the copper treatment...and maybe another dip beforehand.>> I am not going to introduce these fish to my main tank until I am 100% sure of their health.  What do you think I should do? <<You're doing it.  Keep reading...>> Appreciate you response immensely Thanks Best regards Akila <<Cheers, EricR>>

Klunzinger's Wrasse Acting Strange/Proper Preparation of Natural Seawater - 08/13/06 Hi Mr. Fenner, <<EricR here this morning>> Hope everything is fine there'¦ <<Yes, thank you>> Here is a problem which I don't know yet whether it's a big problem or a small problem. <<Hmm, let's see then...>> It's about the behavior of my Klunzinger's Wrasse (Thalassoma klunzingeri). <<A very neat/attractive fish>> He has been acting totally weird lately.  He was the type to cruise around the tank searching for food (ate very well) and even when I clean the tank he never hides. <<Typical, yes>> But 2-days ago he never came up to the surface from his hiding place inside the sand bed.  So I thought he was tired or something but the next day also he never showed up so I was obviously scared as I thought he was dead. <<Not necessarily...have observed this behavior in other/similar species>> Then I put my hands inside and tried to search for him inside the sand then suddenly he just came out moved around like lightning and vanished under the sand again. <<Yikes!...I wouldn't do this, quite stressful to the wrasse>> I repeated my actions again once but got the same results & since then he is hiding. <<Best to leave the wrasse be>> My water quality: Ammonia 0.02 & Nitrite 0.05. <<Mmm, s**hould be "zero"...and may be what is affecting/mal-affecting the wrasse>> I use normal seawater for monthly 20% water changes which I collect from the shallow sea so I don't think I can maintain my Ammonia, Nitrite and Nitrate at '0' levels. <<This is distressing to read.  Unless you are properly "processing" this water (please read here: http://www.wetwebmedia.com/seawater.htm) you are likely introducing pollutants and pathogens to your system>> Am I right??? <<Indeed my friend...this is "false economy"...and may likely mean the ultimate demise of your fish/system>> I didn't check for Nitrate as my test kit is over. Salinity: 1.020. <<Salinity should be 1.025/.026>> My tank is 80G and has only another Blue tang and a Bannerfish which are normal at this moment. <<Mmm, must mention...this tank is too small for the tang in the long-term...and marginal for the Bannerfish...in my opinion>> My green algae growth is fine <<I'll bet...>> & I have a lot of live rock.  What do you think about this situation? <<I have seen these "burrowing" wrasse hide before for as long as seven days when pestered.  In this case I think the problem is environmental (water chemistry issues/pathogens)>> What's up with him? <<Something in your system/water is bothering the wrasse>> Will he be normal again or should I expect the worst? <<Properly quarantine/treat/buffer the NSW, or better yet, convert to synthetic, and you will likely see an improvement>> Thanks, best regards, Rachel   <<Cheers my friend.  EricR>>

Natural Sea Water Hello WWMCrew, I would like to know your opinion on using fresh ocean water or RO salt water. I have used both with different out comes , at this point I am trying to get my levels back to normal from a very low point so I am doing water changes I am finding that the RO salt mix has a low ALK and the CAL is as well and that's the levels that I am trying to get back up without using powders. I am finding that the fresh ocean water has a lot better ALK & CAL levels are there any pit falls I should know about this. I did do a search on your site with no luck. Thank you Chris ***Hey Chris, Sea water is the only thing I use in my marine tanks. I've been using Catalina Sea Water for some years now. As far as collecting it yourself, you need to be careful where you collect it from, as there is a danger of contamination. I know of a reefer who has used water collected off of Manhattan for years now with no issues. My first choice would be a commercial brand that has been filtered if it's available. If you collect it yourself, it could be obtained a few miles offshore if possible. I don't trust the salt mixes. Jim

Natural sea water and artificial sea water Thanks for the quick response, Blundell.  Just one more follow up question. Regarding the new batch of salt water, is it okay to start putting fish, inverts, coral in it already?  << Well, probably not.  I would say that 50% new salt water is the highest percentage I would use when adding fish or corals.  Adding a little new water at a time is a good habit. >> Is it okay to mix natural seawater with the artificially mixed kind? << Absolutely.  Great idea. >> <Actually... a very poor idea... RMF> Thanks again! Martin <<  Blundell  >>

Supplements and natural sea water Hello, I have a problem I have my 155 reef running with some soft polyp corals, brains, featherdusters and some more corals. They have about a week already everything looks good but my gorgonians died. I haven't added <sic> no supplements and the water was from the ocean but cured for a couple of weeks. << Gorgonians often need lots of filter feeding. >> Yesterday I bought liquid calcium from Kent Marine and in the directions it says to add 1/4 of a teaspoon per 50 gallons tank capacity each day depending on the animal load. What should I do I through 3   1/4 teaspoons and I don't think it seems quite reasonable to throw every day this but that is why I am asking you? << Well for now, and with ocean water, I wouldn't add any supplements at all. >><RMF definitely would... NSW is almost always woefully deficient in ready alkaline reserve and biomineral content> what should I do and what supplements should I be adding now please help me I don't want to lose my corals. << Add nothing to natural sea water. >> What about Kalkwasser and strontium and magnesium? << Nope, don't use them. >> please help me. Another question I am feeding my corals with a Coralife liquid target food for invertebrates and with a syringe I target feed all of them once a week and also I give my anemones this is this ok? << Yes this sounds like a good idea. >> Any suggestions? << Feeding, water changes, and lots of light is the best thing you can do. >> Thank you <<  Blundell  >> <...>

Natural sea water continued Thanks for the quick reply, I still have some doubts though, the natural sea water that my tank has right now I bought it and it was cured, but my question is if I bring seawater from the beach but I would go away from the shore to get it and bring let it sitting in a 55 gal tank for some weeks between each water change, should I put a powerhead in it or leaving it just sitting there. << I would probably use it right away.  If you do wait, then I would have a pump in there. >> Is it good to use it after a couple of weeks after sitting? << Probably okay.  I would use it as soon as I could. >> How should I do after I bring it so it is good to do the changes? << Why would it be bad? >> My tank is 155 gal how much should I change and in what period of time? and the water that I am replacing in the sump if it is tap water and I leave it sitting should I use antichlorine? And if it is Reverse Osmosis can I just pour it directly? << I just add it directly.  Slower the better on top off, but I just add about 2 liters at a time. >> But I can save a lot of money with the sea water because I have a house up in the beach and wouldn't cost me nothing, so if you can please help me. << If I had seawater I would use it all the time.  Not sure where you are located but if it is tropical I would use seawater all the time. >> Thank you much <<  Blundell  >>

Natural sea water and supplements continued Thank you much for replying, yes I am located in the tropical I will be collecting the water from the Atlantic side of Panama, << I'm jealous. >> how frequently should I do the changes? << Well I'd say a 10%-20% every month would be great. >> and no supplements have to be added right like Kalkwasser etc..? << Nope, not supplements. >> Well thank you much <<  Blundell  >>

Scripps Sea Water I have been reading over the MANY older FAQ's about natural sea water vs. mixing your own, and am still wondering whether or not it's a good idea (I did also read http://www.wetwebmedia.com/seawater.htm). Currently I have a 75 gallon FO tank, but am going to be buying a 125 or a 150 gallon tank in the next couple of days -- which will be setup mainly as a reef tank with some fish here and there.    While the cost of buying salt mix is miniscule when looking at the overall cost of setting up this new system, If I can cut down on some of the expense by using sea water here and there, that would be great. <No new update here... that is, using natural water still has the same real and potential downsides relatively... being bulky, heavy, messy to tote about, having little inherent alkaline buffering capacity, presenting the same possibilities of biological and chemical pollution, import of pests, parasitic disease>    I wanted to maybe start off using all synthetic sea water to cycle and get things going -- or should I use all natural sea water? Assuming I use all 'synthetic'  and the system has been up and running for some time'¦ I was thinking of maybe substituting some of my synthetic water changes with the real sea water -- I mean come on it's FREE =) <I strongly encourage your attendance in the local Marine Club... you can call Ron Elander at Octopus' Garden and ask him for Maurice Bullock's phone number, the site URL on Yahoo... ask him his personal experiences with Scripps water...>    It just seems that using natural sea water is more touchy, and that there is more preparation in making sure its ready for the system -- while with synthetic is more or less mix and pour in comparison. Thanks for your help Leon. <I am in agreement with your stance. Bob Fenner> Another Natural Seawater Question (with Ozone), 30 April 2005 I read the Water4MarUse, and the associated FAQs, as well as reading how you favor artificial salt mixes (consistency, ease of use, purity, etc) as opposed to natural seawater. I also have read Martin Moe's chlorinate-dechlorinate procedure. <Okay> Bob Fenner also says "store in dark for a couple of weeks, then bleach, dechlorinate, decant or diatom filter (and UV, aerate, ozonize if you want) in-between storage and actual use"  <This is one way to render NSW relatively "safe" for aquarium use> In my current reef tank (50 gallons), I use Tropic Marin with the "Water4MarUse" method (premix, store).  I'm planning a BIG tank (500 gallons), and at the current conversion rate, Tropic Marin costs me about US$50 for 150 gallons, whereas the natural saltwater (plenty of it around here) would cost me less than US$5 for 150 gallons -- so Tropic Marin is 10x the price (no other salt mixes are readily available -- no Instant Ocean here or the like -- I think SERA is also available, but not very common, and priced like Tropic Marin). <I see... well thought out, explained...> One also has to remember that the minimum wage in my 3rd World country (Philippines) is approximately US$5/day ($130/month, or $1,560/annum), so when someone says that maybe Tropic Marin is about the same price as in the USA, it SEEMS much more expensive for us (indeed, a luxury).  <Yes> My question is regarding ozonization of Natural Saltwater -- do I really have to chlorinate-dechlorinate, if I practically make the water sterile using ozone (say, using a 200 mg ozone generator non-stop in 25 gallons or so for a few days, then letting it rest in the dark with cover for another few days)? <This chlorination process is cheap compared with importing pests, parasites...> Would ozonization of this sort have any bad effect on the Natural Saltwater? And is this a BAD idea? <Not a bad idea, just not as complete a one as sterilization through chlorine use> I do want to work on my big tank, but the cost of salt/water changes is a deterrent. Yes, I know why WWM Crew in general prefers synthetic (and it's what I use on my smaller 50 gallon reef).  Actually, I don't mind the procedure set forth by Moe, and (y)our dear Bob F, but is the "couple of weeks" in the dark necessary, and would "super-ozonization" be anything useful? <The O3 use is of benefit, just not nearly as much as the Cl2> Thanks! <Do factor in the need for much more frequent, larger water changes with the use of the NSW... the lack of buffering, yellowing... Not as much as a bargain as it may seem... However natural water is used in many (though not all, especially the more modern) public aquariums... for the very maintenance, disease and pest avoidance issues mentioned. Bob Fenner> 

Natural Sea Water- Worth The Effort? Dear Bob & Staff, <Scott F. here today!> I have a quick question about salt water. I was invited over to a friends house to take a look at his reef tank. It was probably one of the best looking tanks that I have ever seen. As we got to talking he told me his secrete was to use regular sea water on water changes (he has been doing this for over three years). He advised me to try it and get back to him in a month. He was convinced that I would see a big difference in the growth and overall appearance of my tank. I am really temped to try it but I fear I might add something bad to the tank. <A legitimate concern!> I live on long Island NY so getting water would be very easy. Do you believe there are things in natural sea water that would benefit my tank that a regular salt water mix would not?. Thanks in advance for your advice. <Why it may seem ludicrous to say that natural sea water is not as good for your system as synthetic, it can be problematic in some instances. Natural sea water is excellent, but a lot of it depends on the source. Water collected form near-shore sources is a potential source of undesirable contaminants. I have regular access to sea water, and have often entertained the idea of taking some home after a day of surfing. However, when you consider the work involved in preparing natural sea water for aquarium use, you may be better off with a good brand of synthetic salt mix and quality source water. On the other hand, if you are prepared to transport, filter, and store natural sea water, and collect it from a good off shore source, it may be excellent to use. In some areas, natural sea water is available from local fish stores. It's generally collected from clean sources far off shore. Do read up on the WWM site about use and preparation of natural sea water in closed systems. Good luck! Regards, Scott F.>

Real seawater question  9/27/05 Hi guys, <Chris> I've been looking at your site which is very interesting. I live in St Lucia in the Caribbean (island near Barbados) and the sea is full of Caribbean tangs and other things that I used to catch when I was a kid and I kept them quite successfully. <Have been to the Sandals Resort on this island, diving there... very nice> I used real seawater collected from the ocean, and never had a problem, except maybe more than usual regular cleaning. <This is... "about it"> It's been years since I've kept fish and I want to get started. I've been reading the articles on real vs. synthetic seawater and the consensus seems to be that real seawater is more hassle than it's worth. <Sometimes> My question is this: Since I live so close to an essentially unpolluted sea (five minutes walk!) would it not be better for me to go ahead and use the real stuff? I'm planning to set up a reef system with mainly ocellaris clowns - the anemones that I collected locally worked very well with the imported tomato clowns that I used to have. I'd not include any other fish except perhaps a Caribbean tang captured locally. I'd appreciate your thoughts! thanks, Chris <Just a bit more water changing... Bob Fenner> Collecting sand, water, flora and fauna from Carolina Coast 10/13/05 WWM team and friends, Good day and hope you are all well. I want to first state for all of us out here in apprentice/journeyman land, appreciation for your patience and expertise.  <Thanks for the kind words! We are truly happy to help and contribute!> Item 1: Unrelated to topic but have to state to Bob the last status on the SeaClone 100 skimmer (my pc crashed, lost all mail so thread is not intact). It has been up and running over a month now and contrary to most popular opinion, working rather well. I recommend it.  The new revisions seem to be fine-it could still be improved but can't everything? I am getting dry foam and about 1 1/2 cups a week of green/black stout from a 38 gallon tank with 27 gallons of actual water (yes, I was anal about ensuring I knew how much water for dosing, changes, etc.. :) ). So if you like, feel free to post this part with the other thread on the skimmer section. Only issue is that for the money, I should have gotten the 150.  Local P*TSm*rt stores here honor their online web price that is generally $30 less than their actual stores and other LFS in the area wanted $130 and up for this skimmer - not a good buy then :). Only question on skimmers in general is do ya have to use a prefilter sponge? When you take it out to clean it, half of the stuff it filtered leaks into the tank anyway so what's the point?  <I am glad to hear that your SeaClone is working. Your experience is truly and exception. Prefilters are not necessary.> Item 2: The meat of the questions. I have the opportunity to get a gently used 75g glass/stand/canopy with darn near everything including canister, lighting and Magnum HOT for CHEAP. I would like to use my knowledge acquired from YOUR brains to do a better job this time, however, I am still a cheapskate soon to being out of work. <It is nice to find good deals! I am not a fan of canister or HO filters for marine tanks (see here: http://www.wetwebmedia.com/ca/volume_2/cav2i5/Filtration/Filtration.htm). I would suggest selling these filters an applying the proceeds to live rock and a skimmer.> Since I live a couple hours from Wilmington, NC and my brother has a beach house one block from the sound, intracoastal AND TopSail beach that I have access to (he is the comfortable one in the family), I would like to know if it would be an okay mix to use sound/surf sand and water and perhaps plant life, yet, stock with the typical tropical flora and fauna like damsels, crabs, corals, etc..?  <There are many issues with this. Any temperate life (brought with sand or intentionally introduced) will not survive for long at tropical temperatures. Some tropical species make their way up into the Carolinas during summer months, but you have to really know your stuff!> The water tests well for sg and basic tests. The sand is fine, brown Atlantic sand, not aragonite. Not sure if it has silicates but have to imagine it is as good or better than the Home Depot sand so many people seem to rave about that looks like someone swept up sand blasting sand after use and put it in a bag for sale.... Additionally, I do find small rubble rock and would like to know if this is appropriate as well.  <This sand is surely high in silica, although I am don't believe that this is a significant problem. I would be more worried about pollutants (sewerage, fertilizers, pesticides, boat fuel, etc.) from sand collected on or near shore. "Live sand" is generally collected from areas around reefs in at least a couple of tens of feet of water. The same applies to the rubble. Using natural sea water for water changes has many benefits if you have access to it, but it can also introduce pollution or disease if you aren't careful.> I am not a naturalist and don't know the micro flora/fauna indigenous to my region but imagine that in using the sand/water I will likely find out and want to ensure that it is ok. I have refrained from using local saltwater to this point not for fear of contaminants or pollution (NC is actually highly stringent in enforcement since we are a shellfish producer) but for fear of it not being correct in some way from the normal environs of the stock.  If that is not an issue, I much would rather trek down to Wilmington for a weekend or two a month at the beach for free and stock up on water than continue to spend $$$$$ on RO and salt mix. And spend those dollars on caring for my marine dependents in other ways like a refugium and such.  I would imagine the local water has good bacteria strains as well that the mix does not. I would also imagine that cycling should be much more effective. Your thoughts? Sincere appreciation and regards, Bill  <While the use of NSW is inexpensive, the risks are also high. It may work well for a while, but it is a game of Russian roulette. Facilities that use NSW usually filter it aggressively as well as ozonize it to prevent introduction of pathogens and pollutants. This process is only cost effective on a large scale. Best Regards. AdamC.>

Red Tide... dangers of using natural seawater - 01/24/06 Gentlemen, <... and some ladies here> Thank you very much for your services.  Your site is always the first place I look for answers. I got a quick question about red tide. I collected natural sea water from a local spot yesterday (Captiva, FL). The water quality is usually excellent.  However, while collecting I noticed very dense particle matter in the water that made it look cloudy. <Yikes....> I figured it was just suspended sand, so I would let the water settle over night, siphon it out, filter it, and be good. <... real seawater should be thoroughly and religiously treated... for a couple of weeks... in the dark, possibly with bleach/chlorine, dechlorinator, decanted... See WWM re.> However, curiosity got to me and I looked at some of the water through a microscope. There was some really great stuff, and some not so great.  I was able to ID a couple K. Brevis cells.  I had checked on Floridamarine.org for red tide and it said: "Southwest Region: Samples collected this week from Mullet Key in southern Pinellas County and Anna Maria Island in northern Manatee County contained very low concentrations of Karenina brevis, the Florida red tide organism. All other alongshore samples collected between Pinellas and Collier counties contained no K. brevis. In the Florida Keys K. brevis concentrations ranged from not present to very low in three samples collected southwest of Sugarloaf Key and was not present in samples collected southwest of the Marquesas Keys. Offshore sampling from Sarasota to Lee County late last week detected K. brevis at medium concentration in 1 of 15 samples at a site 26 miles west of Englewood." What I wanted to know is if this low level of K. brevis could cause damage to my 60 gal reef? <Yes... if conditions permit, these algae will reproduce...> If so, is the damage only to fish, or will it affect corals as well? <All life, indirectly> Thank you very much for your help. Sincerely yours, David <Thank you for sharing. I have numerous experiences (most second-hand thank goodness) with wipe-outs from natural seawater use. Bob Fenner> Marine water treatment, fish farm in Bali Hi Bob, <Hello Charles> I have read your news forum daily and I must say you are simple amazing like a walking dictionary in aquaria industry. Thanks for enlightening those like us who's still figuring out bits and pieces of aquaculture knowledge. I have indeed gained a lot by just reading your aquaria news in the forum. Hope to meet you one day. <Me too> I'm currently running a marine fish farm and would like to know any affordable and effective ways to sterilize my system water. Currently I'm using 2 UV light tubings for 15,000 litre of water in my holding however one aquarist told me to get commercial grade with multiple UV tubings in order to be effective. But getting commercial grade UV light tubings prove to be very expensive. How abt ozonizer for 15,000 litres of water? <Could be done... seek out the larger Sander's (made in Germany) units. If you have room, storing the water in the dark for a week or two, possibly bleaching it (with commercial concentration sodium hypochlorite) THEN dechlorinating it (likely with thiosulfate) are options as well> I have tried submerging LR in fiber glass but in less than a week most of them were dead. DO they need strong sunlight or constant lightings? <More needed are good protein skimming, water changes when water quality slides greatly> What other condition do they need in order to survive? Is it possible to put my posting in more obvious spot as I'm desperate in finding serious business partner for my uncle Ong Kian Huat in re-activating his existing Bali farm? <Where do you suggest?> It's such a waste that this farm with 100 tanks sit lying there untouched whereas many new investors were trying to start from scratch. <Agreed. Got to have aquariums, space> Sorry to email you so many questions as finally I have found a guru which can satisfy all my curiosities in aquaria matters :-) Pls advise. Thank you. Cheers, Stephen <Keep on planning, searching, contemplating your possibilities. Bob Fenner>

Natural Sea Water (9-14-03) Hey Guy,<You got Cody today.> I'm from Singapore.  Recently I have just converted my freshwater tank to a marine water tank. I did not buy sea salt but instead I took it from my near by beach. the sea water has some how evaporated and is it okay for me to collect some sea water from the near by beach and fill it up again or should I buy sea salt from the salt and mix together with my exiting sea water. pls help me.<You can get water from the ocean but it needs to be treated first.  I would just buy salt as it is much easier.  You can find some info on this here: http://www.wetwebmedia.com/seawater.htm.  Cody> thanks and best regards, Calvin.

- Using Natural Sea Water -  Hi guys  I'm from the east coast of (Queensland Australia) and I was reading about natural sea water on your page. I have access to natural sea water 24/7 it takes no time at all to collect but from reading your page you seem to not like natural sea water? <It's true.> Is this because you are USA based and some don't have the access? <Well... I thought the pros and cons were well laid out in the article, but to answer your question, no... there are several places here on the west coast, and also a couple on the east where sea water is collected, sand filtered and made available to the public. In general, natural sea water is typically inconsistent... red tides, need for supplementation, organic life, and other issues that can cause complete wipe outs if not handled correctly. Have several friends who have been much less lucky than you.> This tank I have now is my 3rd tank being the smallest of all of them only 220L or 60 Gallon in your eyes over a time of 12 years and I have never used any thing but natural and I have never had any problems i.e. disease and I don't quarantine my fish invert or coral. I'm I just lucky? <Very... I'd look both directions before you cross the street next time.> I collect my own fish, invert and coral from the reefs at my door step so to speak.  I don't treat the water at all I don't even heat it up I some time do 20L a week some time I go 3 to 4 weeks and do more. I'm I doing it wrong? Or am I just lucky and I am heading down the path of death for my tanks. <I think you are lucky... and for my own way of thinking, there is always the risk of driving off the cliff, so to speak. If we were talking about playing a game of cards and you had just run the house, I'd tell you to leave the table... most every good streak is followed by something less favorable. But that's just the way I think.>  Don  <Cheers, J -- > 

The Real Thing-Or The Synthetic Thing? (Salt Water) Hello Gang- <Hi there! Scott F. with you today!> Merry Christmas ! I hope Santa was good to everyone ! <Sure was! Hope your Holiday was great!> My question is on the use of "Catalina Water" vs. synthetics like Instant Ocean. I read an article by Dr Shimek (sp?). He makes the case for use of Ocean Water obviously. Have you heard anything on this product ? Is it in wide use among hobbyists ? Pros/ Cons ? What do you recommend ??? Thanks and Happy New Year !  Dan <Well, Dan - I have used the product a number of years ago, and did not have any bad results from it. However, in recent years, I have heard various concerns posed by hobbyists regarding it's purity and source (some people have implied that the water is collected not too far off shore, with potential exposure to pollutants, etc. Perhaps these concerns are unfounded, but I prefer the control afforded by many of the good synthetic mixes and good source water. Seems kind of funny, but I recommend synthetic for many, many hobby applications over natural sea water. In general, we have many concerns about the use of natural sea water in home systems, which can be found throughout the site (use our Google search feature using the key words "natural sea water"). Hope this sheds a bit of light on the topic. Regards, Scott F.>

Natural vs. Mixed seawater I have just read your article on Natural Water Verses Mixed and was wondering what water the Birch Aquarium uses. Is it the same as the water from the pier? >>Hi, Marina here for Bob as he's currently out of the country (unless he took that starship..). To the best of my knowledge the Birch Aquarium uses natural, well-filtered seawater just as the Long Beach Aquarium of the Pacific uses, though I would guess that Birch's source water might be a little cleaner. Hope this helps! Marina Thank you, Mark F Hebert  <As far as I'm aware it is the same source water... most of the "local" tanks are open circuit... and the tropicals largely recirculated. Will cc Birch Aquarist Fernando Nosratpour here re as well for his input. Bob Fenner>

Re: Natural Vs Mixed Mark Wrote: >Natural vs. Mixed seawater >I have just read your article on Natural Water Verses Mixed and was wondering what water the Birch Aquarium uses.  Is it the same as the water from the pier? Hello Mark, As Bob and Marina both mentioned, the Birch Aquarium is an open system aquarium. We use the same water available to the public, located at the base of Scripps Pier. The water is sand filtered, removing most particulates. Quite a bit does get past the filters though. This is most obvious when we have red tides. The dinoflagellates causing the red tides get through. I usually tell hobbyists not to use this water during red tides, when there's heavy surf or when it's raining (runoff). All these conditions make for foul water in a closed system aquarium. Because were open system, nutrient build up is not a major concern. With that said, we use this water 24/7 and it's been great. Good Luck, Fernando <Thank you for "chiming in" Fernando. Hope to see you soon. Bob Fenner> Fernando Nosratpour Assistant Aquarium Curator Birch Aquarium at Scripps

Keeping Seawater Dear Bob <Brian> I am two minutes from the sea. However, could you please tell me how long can I store seawater in a closed container in a cool shed, before it goes off. I am hoping to breed brine shrimps soon. <For a few to several weeks... take a look at the very bottom of long-stored water... as there may be appreciable content that accumulates there... and this may be avoided by decanting (yep, the fancy term used for pouring off vino excluding the dregs on the bottom)... maybe by siphoning off the water just above it. Bob Fenner> Many Thanks Brian Cotton

Using "The Real Deal" (Natural Sea Water) Hi, <Hi there! Scott F. here today!> I have a 1000L storage tank. (1) I have access to collected sea water. How do I store it. <A food-grade plastic container in a relatively dark place should do the trick> I read that I must just leave it for a week or so before I use it. What happens to the die-off of plankton etc. Do I leave it to settle at the bottom of the storage tank and siphon off the top? <That's a good method, or you can actually run an inside box  filter with some mechanical media, like Ehfi-Mech> Your site said you must circulate and aerate mixed saltwater. Do you have to do this for collected sea water as well? <I would> (2) I also have access to water from the local oceanarium. Would it be better to use this water instead? Salt mix is really expensive here in South Africa therefore I don't want to mix seawater if I can find a solution to using NSW. Thanks John Squier <I agree, John. If you can find a reliable, inexpensive source of quality NSW, by all means use it! If it's good enough for a public facility, it should be fine for hobbyist-level use. Good luck! Regards, Scott F.>

Re: Juvenile Queen Angel is sick, but from what? Hey Bob, Just did a 25% water change with NSW from my local inlet, on incoming tide. <Sorry for the interjection/ruption, but do you do much to the new real seawater before placing it in your systems? We've had some real trouble over many years time (periodically) with just using the raw product on the west coast (U.S.)... most folks now store the new water in the dark for a week or two, others bleach and dechlorinate it... still others use U.V., other novel ways to "kill" what is live in it before applying> So we'll see what happens in the next couple days with the Queen, Thanks for the input!!  Now I have a question about my protein skimmer. I unplugged it earlier, before I emailed you, because I was going to add green ex. After I did the water change, I plugged it back in but its not skimming.  I can hear the pump working but no skim action. I'm going to browse the faq's on the site and see if that has been covered there. I'm sure it has, as everything is!! Thanks for all your help!! Ray <Is this a Venturi type? You might want to check the intake (blow through it)... or take the whole thing to the sink, take the pump apart (to check for foreign matter on the impeller, spindle...) and clean it thoroughly... Also, do check the intake line to the unit... any obstruction, restriction there will produce this non-result. Bob Fenner>

Re: Juvenile Queen Angel is sick, but from what? Uh oh. No I just used fresh sea water, but have heard of letting it sit. In this case I just didn't have time/ or any NSW around, but will in the future. I wonder if water purchased from the local fish store has been treated etc. <The big brand here on the other coast is not... though some folks claim otherwise. Please read here: http://www.wetwebmedia.com/seawater.htm and the associated FAQs files.> and is ready for immediate use because Id like to do another water change of that size in a couple days. Its a much faster method of raising salinity as opposed to replacing the evaporated water with NSW. My skimmer is made by SeaLife Systems and has worked great up until this point :). It seems the most logical thing is some sort of restriction inside the pump (Rio 800 I believe), because it makes a lot of noise now not running smoothly as it did before.  <Turn it off... take it to the sink (along with the skimmer if need be) take it apart and check... easy to do> The Queens demeanor hasn't really changed, she's still being awkward; sort of staying in the corner upside down. :shrug: <Might just be low dissolved oxygen... the skimmer running will remedy this> I think only time will tell with her, she's been normal up until this point though, nipping at all the rocks and what not. In the morning I will take apart the pump on the skimmer and clean out any mess inside, hopefully erasing that problem. Thanks again for your help my friend!! Ray <A pleasure. Bob Fenner>

Re: Juvenile Queen Angel is sick, but from what? I'm on it! Thanks BOB! <Please make it known what you do, how all turns out. Rootin' for you, Bob Fenner>

Re: Juvenile Queen Angel is sick, but from what? Hey Bob, Bad news: the Queen was dead this morning when I awoke. She was floating on the surface, near the overflow box. :( I'm not really sure what happened to her. Her gills were RED and swollen. <Rats! Sorry to read of the loss.> To add insult to injury I can't get the pump on my skimmer to work properly. I took it apart and there appeared to be no gunk/ restrictions inside. I ran warm water through the pump for a few minutes and cleaned of anything that was there (not much). Its also not sucking air through the intake, and there isn't anything blocking airflow in the tube or on the inlet on the pump, so I don't know what to do.... Any input is greatly appreciated. <Try hooking it up with a "direct" connection to your tank water (to discount the possibility of intake restriction)... it may be the pump is bunk (this happens)... next, a trip to your LFS, or visit from a sympathetic fellow reefer. Re the Lion eye opacity and Angel loss, I am still of the strong opinion that these troubles are/were directly related to diminished environmental quality... and advise you to get your skimmer re-going, and develop and adhere religiously to a plan of storage (in the dark) of new seawater (for at least a week... for me, two)... or switching to synthetic. Bob Fenner> Frustrated Ray Re: Juvenile Queen Angel is sick, but from what? Hello Bob, I went to the LFS and had them inspect the pump and it turns out that the shaft somehow got bent. <Ah ha!> So that explains that issue! Tomorrow I'm going to the store that I prefer and see if he can get me a new shaft or a new pump. Thanks for all the help Bob!!! Ray <You can call me Sherlock, well at least "Not Late For Dinner". Be chatting, Bob Fenner>

Ocean Water? Hello there, I just found out about your site from the Nov. 2002 TFH magazine.  <welcome, my friend!> I spent over an hour searching around and reading your FAQs and plan on spending more time there (great site!).  <excellent... and do share your wisdom in kind with others> My question is the use of ocean water in polyp/coral production tanks I would like to set up.  <it is very unlikely that I would ever recommend natural seawater for many reasons. The basics however are: very unreliable/seasonally fluctuating composition (pH, calcium, etc), the expense (time, space) of preparing it for safe use (ozone, bleach, filtration), the unlikelihood that you live in a remote coastal region and can draw pristine water from 5 to 10 miles out without effluent from dense coastal populations contaminating it, etc. Even if you get the water for free... it is unlikely to be worth it and almost certainly not as good for growing coral as a quality sea salt and its consistency. I would recommend Tropic Marin or Instant Ocean sea salts>  I would like to propagate for trade with friends and local sales and trades.  <excellent! Do let us know how we can help/advise> My questions are, with sea water available to me (central Cal. coast) how would I treat it for safe use in the system (e.g.. aging, U.V., etc..)?  <bleaching and dechlorinating are inexpensive and fairly easy. Decant the top water and store dark for 2 weeks. Aerating and buffering 2 days before use too. That may be enough... but I still wouldn't bother. And I will say that it will eventually be dangerous (1-2 year picture) if you are taking water from within 3 miles of most any coast> Could I use a flow through type of system as this would be the easiest setup for me?  <by flow through, if you mean raw, untreated... not recommended without massive micron filtration and ozone> If a flow through system is an option, how would heating the water be performed (I have heard of flow through heaters but have not seen them available)?  <very expensive... if the scope of your operation is large enough we may be able to reckon the expense. For most aquarists, synthetic sea salt provides peace of mind, reliability, consistency, etc. Bets regards, Anthony> Thank you in advance for any help you can provide. Dan

Natural Seawater Use Hello everyone, good day to all of you! I live a couple miles from the ocean and I have often tested it's water to find wonderfully, perfect conditions. Never a nitrate, salinity perfect! Ahhhh, to be Mother Nature! These are my questions: 1.) Could use this for water changes? <You could, but I don't recommend it. To many variables and not enough control/safety.> 2.) How would this water keep, if I put it in a bucket with a powerhead? <Take a look here for additional information http://www.wetwebmedia.com/seawater.htm> Thanks guys, I'd be lost without ya! Pamela <Have a nice day! -Steven Pro>

Natural Seawater Use Thank you, very informative link! I especially like this part, "Some folks assert that natural water must be best for "natural" livestock. Maybe they think their aquaria are "little pieces of the ocean"; most systems more closely approximate "little sewers". <I love that part!> Cheers! Pamela PS ~ I'll stick to synthetic! <Me too! -Steven Pro>

Using Natural Sea Water Aloha WWM Crew, <Howzit?> Thank you for all your help.  I truly appreciate the resource you provide.   <Our pleasure- always great to help fellow hobbyists!> My question involves the use of natural seawater in my 55 gallon FOWLR.  I live on the island of Oahu and have access to seawater through a University of Hawaii marine research center on Sand Island. I was told that the water is brought in from a few miles out and is stored in large containers.   Of course, its free so the idea sounds great to me.  I'm just wondering what the drawbacks are.  I read through the FAQ's, but I was wondering if any of the issues are different due to my location.  Would it be okay if I just let the water sit for two weeks and check the PH before use? Mahalo Nui Loa, Jeff <Well, Jeff, natural seawater is certainly good stuff, but it actually has a few drawbacks in closed system aquaria, regardless of its source. Among the drawbacks is that fact that it contains a variety of potentially problematic microorganisms, which can survive many pre-filtering processes. The other potential concern is the limited buffering capacity of seawater in closed systems. That being said, however, it is still nice to use. If you're going to use it, it's a good idea to let it sit in a dark place for a week or so, which lets all of the good and bad stuff die and settle out, then filter it and maybe run a filter with some PolyFilter or carbon for a few days, then it's good to go. Seems like a hassle, but it's worth the effort. Hope this helps a bit!  Malama Pono, and A hu'i hou! Scott F>

Natural Seawater Use (from John Foster, MASLAC) Just my experiences...  I have used plenums in all my tanks (125, 180, 240) for between 3 and five years.  Some of my sandbeds I disturb a lot and often and others only a little.  I have never had any problems.  I will say that when I set up my next tank I am beginning to think that a deep sand bed may be just as good and I will only go with the sand bed.  Charles Delbeek compared them side by side (with and without  plenum) and found very little difference.  It did seem that the tank with the plenum lowered nutrient levels faster when they were elevated, and this has been my personal experience.   John   I tested Scripps water about 5 years ago and NO3, NO2, PO4 were not detectable.  ALK and PH were perfect, however, Silicates were high.  I used a HACH Professional model test kit.  The water is alive with bacteria not Nitrates and Phosphates.  What I have noticed is that if you seal the containers and/or the temperature rises quickly, there will be a rapid die-off of the bacteria/[plankton.  You can tell by smelling the water.  If this happens, do not use the water until you store it in the dark sealed for a couple weeks. I have used freshly collected water up to a week after collecting it but I store in in a cool place with the container open.  Don't leave the water in the direct sun for too long after you collect it if you intend to use it right away.    As far as plenums go, I don't recommend them.  They seem to work well until something disturbs them (inevitably something will) and then watch out!   This happen to me with a Pistol Shrimp and caused my tank to cycle.  I lost some of my more sensitive corals.   Happy reefing,   Keith   I have heard such conflicting information about using Scripps over RO/DI +salt that it is really bothersome.  One LFS says only use artificial water b/c the Pacific ocean water is too rich in Nitrates/Phosphates etc.  It is true that our water is very rich in nutrients, that's why we have such large kelp beds, the fastest growing "plant" brown algae, in the world.  Other LFS's say that there is nothing wrong with Scripps water.  The first LFS attributed my algae problem to using Scripps water, but with biological controls and more sand in my plenum the algae are gone.  So was it the water, or lack of good biological controls?  Or a combination?  After 2yrs of using Scripps water for my 80 gal reef I would say that it works just fine.  Has anyone sat down and tested some artificial water and some Scripps water to see how they compare in the NO2/NO3/PO4 department.  It would be nice to have a seawater nutrient profile   for different times of the year and see how it fluctuates.  I would expect nutrient levels to go up in the spring and early summer when   we have the most wind, and then to drop off when the upwelling cycle   is over.    by the way:  how do people feel about plenums?    > Scripps's water, it's water you can get for free at the la Jolla Scripps aquarium, many people go to get their salt water that they use for their own systems, the water over there it's perfectly balance (PH, N2, N3 etc).   > But I also heard, that the water over there contains many plankton and bacteria that is harmless to their extremely large system, but can be a wipe out to small systems.

Going Natural? (Use of Natural Sea Water) Hello Again WWM Crew, <Hi there! Scott F. with you today!> As always, I'd like to say marvelous job to all of you.  Great team effort.   <So glad that you enjoy the site! The crew here really enjoy bringing it to you!> I am 3 weeks into the curing of 25 pounds of live rock, 50 lbs of live sand.  I am confident that I am nearly complete with these test results: Salinity: 1.023 Temp: 78 pH: 8.3 Nitrates: 5ppm Ammonia: just slightly detectable Nitrites: 0 Calcium: 450 I do weekly/bi-weekly water changes of 5 gallons.   Am I done?  Cut back on the water changes? <I'd keep 'em up for a while longer. ammonia should really be undetectable> The water movement is good, but I have constant bubbles forming on the underside of the Tonga branch.  I've learned on your site that this may be an indication of bacteria: Beneficial or not? <Well- really hard to say...It could even be hydrogen sulfide, etc...Most likely, however- nothing I'd be overly concerned about at this point> And if not, could phosphates be a problem?   I haven't tested for them (I know, I know...) <Gotta test for 'em to find 'em!> I use a CPR Bak Pak skimmer, and have about 1/4 of the BioBale still in the return side.  This will be FOWLR, should I keep it?  Also, would a small branch of my Tonga in the skimmer instead of the BioBale be beneficial? <Well, it essentially performs the same function- serving as a biological filtration media within the skimmer/filter unit> Secondly, on a recent trip to an aquarium in San Francisco, I discovered that they sell natural sea water conditioned for tanks at a reasonable price.  I already have artificial sea water in the tank.  If I decided to take advantage of this, would it be a bad idea to mix in the natural sea water in when doing water changes? Also, should I dilute this a bit with RO water, since the salinity is 1.025? <Believe it or not, I do not favor the use of natural sea water under most circumstances (and I leave near the ocean, myself!)...The necessary "prep work" to assure that it is made suitable for use in captive systems is too great, IMO.>   And lastly, my sand bed is between 3-5 inches across the tank.  I've read that you need 4+ for denitrification.  Is it worthwhile in the long run if I were to add enough that it could be 4+ across the whole bed? <Yep- I'd be shooting for 4 inches plus!> I'd be up a creek without your advice!!! Thanks always, Ryan Bowen San Francisco, CA <And we'd be "out to sea", without everyone's support! Thanks for stopping by! Regards, Scott F>

Buying premixed water, Buying Seawater Sorry to bother you again, I just remembered that I also needed to ask you another question. The local aquarium where I live sells salt water from the sea for 5cents per gallon. The salinity is a bit low at about 28 ppt. Can I raise the salinity with a salt mix? The water they sell contains phosphates, is it advisable to remove it? If so, how can I remove it? Bottom line, do you think I should go ahead with this water from the public aquarium or stick with mixing with r/o water and a packaged salt mix? <too much risk of contamination or seasonal inconsistencies with natural seawater. Look back through past FAQs for proper treatment of demineralized water. But do mix up your own synthetic seawater for consistency and peace of mind. Unless you personally feel like boating several miles off shore to retrieve seawater and bring it back home to filter and sterilize it...hehe. Kindly, Anthony>

Re: buying premixed water In reply to your comment about water treatment from the public aquarium, the water from there is U.V sterilized and filtered and they use the same water in all of their coral reef exhibits, so perhaps you thought I would be the one collecting the water myself? Maybe I was not clear in questioning, but could you re-advise? Thanks again. <I would still advise you to continue using RO water and a good quality synthetic salt mix. -Steven Pro>

Red Tide Questions Can someone answer a few questions about the red tide?  1) I understand it is a surface condition, is water drawn from Scripps pumps really affected? <Mmm, yes... the principal species of algae (Dinoflagellates... Gonyaulax, Gymnodinium spp. if memory serves) are principally surface/epipelagic... but enough of these single cells and their chemical metabolite does make it to the depths of the two intakes at the end of the pier where water is drawn/pumped up> 2) What, specifically, is the problem if introduced into a mature reef/fish tank? <General toxicity. Interference with fish respiration/electron transport... "cascade" effect with other biota> 3) I usually heat and filter Scripps water for a couple days before using it, often with LR or bio-balls from sump in there as well. Could easily add UV. The question is, can you filter out or kill off the algae? <In a matter of time, yes... but more at play here than live algae... Better to store in dark for a couple of weeks, then bleach, dechlorinate, decant or diatom filter (and UV, aerate, ozonize if you want) in-between storage and actual use.> TIA for any answers to these questions, David. <Bob Fenner, who along with Mark Ferguson wrote about using "Scripps" (William TV.) water for booklets back in the (yikes!) sixties.>

Saltwater Bob, I patronize a local marine LFS store that sells salt water obtained from the ocean. It is run through a UV sterilizer. I checked your posts and couldn't' find a discussion on this matter. My questions: a. Is water made from packaged mixes superior to sea water? <For most settings, circumstances, synthetic is superior...> b. If so, why? My thinking is that it would be hard to beat God's mixture but I have a feeling you are going to vote for a mixture. <Yes my friend. The "natural" water is fine in nature... Aquariums are more akin to little sewers than a slice of the ocean... Please read here re this issue: http://www.wetwebmedia.com/seawater.htm and the linked FAQs> c. Even if a mixture has higher ratios of necessary components, is there a likelihood that sea water has phytoplankton's or other micronutrients that mixes lack? <And pollutants, pests, parasites...> As always...thanks tons...you guys are the best! William Snyder, Stuart, FL <Glad to offer our input and opinions. Bob Fenner>

Low pH and alk but high Ca Hi WWM Crew, I seem to be having a problem with low pH and alk in my 50 reef. My readings are as follows: pH-7.9 alk-2.5 Ca-490 I am adding daily Two Part ESV B-Ionic 25ml of each. I also add 60 ml daily of Kalk. Additives are all added manually. The tank is 3 years old and I do two 10% water changes monthly. For the last three months I have been using ocean water for these changes. <I would recommend going back to synthetic water.> I have noticed my green star polyps have not been opening full for about 3 weeks. Could the low pH and alkalinity cause this? <Yes> All other organisms doing fine. Any advise greatly appreciated. Mario <I would do several large (50%) water changes to bring your parameters back into line. Once they are good, you should be able to easily maintain them with the Two-Part additives. -Steven Pro>

Re: Low pH and alk but high Ca Thanks for the quick reply Steve, why would you not recommend natural ocean water? <Generally, chronically low in pH and possibly contaminated with pollution, parasites, or bacteria blooms.> I figured the plankton in it may help feed some of the SPS corals, clams, etc. <Parasites are also in that plankton. -Steven Pro>

Marine set-up query Hi Anthony Sorry for the 20 questions. I know some answers are in the FAQ's and I wouldn't mind your opinion. Finally, This is my proposed initial set up- 404 with carbon and some bio-balls, run my SP2500's as powerheads, skimmer and live rock. How much live rock do you think for a 70Gal tank? <more the better, depends on the type/density of rock used... 100-140lbs of Fiji rock on the high end> What test kits are necessary? <begin with ammonia, nitrite, nitrate, alkalinity and calcium. Phosphate if nuisance alga persists> How long do I wait before adding fish? <at least a month would be nice> Should I use Syn sea water even if I live by the ocean? <ABSOLUTELY!!!! Natural seawater has numerous dangers and problems for long term success. We could talk for hours about this. Rest assured, use synthetic seawater for consistency and safety... especially if your tap water is even reasonably good> Should the carbon be used constantly or put in once a month for a few days. There seems to be different ideas. <constantly with small amounts changes frequently. Monthly can shock corals and some live rock fauna terribly> A guy at work said not to worry about it. <better safe than sorry... no harm to daily carbon, but many possible dangers with intermittent or without> Anything else I should be aware of? <strangers with beady eyes> Yet another suggestion I've had is run a fluidized sand bed filter in my 404 line. <fluidized bed filters are more risk than they are generally worth... only employ if you will have a massive fish load> Thanks for everything. Regards Scott <best regards, Anthony>

Natural seawater Hi Bob, I read your Q & A daily. Great Information! I have never seen my question addressed though. I have the good fortune of living on the Gulf of Mexico. I have often wondered if I could use natural seawater for my reef tank that is first circulated a UV source to kill bacteria. Any Suggestions?  Thank you, Gail <<Do have some standard ideas about "real" seawater (versus synthetic)... The real thing can be made to work... minus the possibilities of pests, pollution, parasites, by storing the new water in the dark for a week or more... then mechanically and UV filtering it... before use. Bob Fenner, whose synthetic/natural water input in greater detail can be found at www.wetwebmedia.com >>

More questions (seawater making) Hi Bob, (I'm getting to be a real regular around here) <Careful, you may end up answering queries...> A few questions: 1: As I mentioned before, I'm moving. If the house we purchase has copper piping for it's water supply, will the leeching that occurs contain enough copper to poison the tank for reef animals? <Generally inconsequential... not much concentration comes through to matter... but this is one of the myriad reasons I strongly suggest pre-mixing and storing synthetic seawater... per the rationale, protocol of the same name on the www.WetWebMedia.com site> 2: I'm going to get a Rubbermaid Brute (tm) for holding my water (thanks for pointing those out), would a couple of inches of aragonite (sp?) sand in the bottom be a good idea?  <Mmm, not really... more trouble to pump/move water...> I was thinking it could help buffer the water and lead to less of a ph shift when adding it. <Minimally... adding a bit of baking soda, like a teaspoon per ten gallons, would be much better> 3: I'll be living near (roughly 40 miles) from the Oregon coast, would obtaining a few gallons of sea water and using it to inoculate the tank be a good idea, or should I not bother since the local biome is so different than a tropical reef? <Not so much the difference in living component of this water, but the issues of potential pests, parasites and pollution would dissuade me from such usage.> thanks again! Mike <Be chatting. Bob Fenner>

Using FRESH seawater for water changes Hi Bob, I live in the Florida Keys and we obviously have an abundance of fresh, clean seawater around us here, and I was wondering if its okay to use this directly from the ocean for water changes? <I wouldn't... better to develop, adhere to a regular protocol of collection, storage, treatment ahead of use. Somewhat detailed on the www.WetWebMedia.com site on "Seawater Use" or such> I heard somewhere that you have to "cure" the seawater in a light-proof container for 2 weeks. If this is the case, why? <Cuts down, discounts the likelihood of introducing a "bug", organisms that you may not want... Bob Fenner> Thanks in advance, Brad

Water change (natural seawater use) Hi, I have 135 Gal tank with fish and live rock. Been running for 6 months now. I made one small 10% water change about 2 months ago. Nitrates are rising. My local fish store just set me up for a water change with ocean water (guy comes with a truck of ocean water; that's how tank got filled) and they are suggesting 50% water change!  <Bigger sale> I am worried that is too much. I read you recommend 10 to 20% frequent changes. <Yes, in general> Should I make up the lack of past frequency with a such a large change for this time and get on with a regular schedule and smaller changes?  <More frequent, partial water changes are best> What is the maximum % you would suggest for this time? <twenty five percent... Read about natural versus synthetic water use on our site: http://wetwebmedia.com/seawater.htm and develop a protocol for storing, treating the natural if you're going to use it... It's rarely the better route to go... Be chatting, Bob Fenner> Thanks in advance
Thierry Genoyer

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: