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FAQs on Tap water Filtration: Reverse Osmosis, Deionized, Distilled Water... 6

Related FAQs: RO/DI & Distilled Water 1, RO/DI & Distilled Water 2, RO/DI & Distilled Water 3, RO/DI & Distilled Water 4, RO/DI & Distilled Water 5, RO/DI & Distilled Water 7, Rationale, Selection, For Commercial/Large Output, RO Water Storage, RO Water TreatmentMaintenance/Repair, Deionizing Source Water Filtration, Kati-Ani DI Units, Kold-Steril Units, Water ChangesWater Make-up, Nitrates

Related Articles: Water Purification Using Reverse Osmosis, Reverse Osmosis, A Multipurpose Tool By Mark E. Evans, Water ChangesWater QualitySynthetic or Natural Seawater, Nitrates

Conditioning RO/DI Water 08/26/05 I have a 55 gallon saltwater aquarium set up for 2 yrs now.  I just purchased a ro/di system and want to know what do I need to do to water before I put in tank? <<Congratulations. IMO, RO/DI systems are one of the best investments you can make. The water from the RO/DI unit can be used directly as top-off water. You can also use it for water changes. Just mix with salt and age.>> I was told to use Kalkwasser but not sure about how to use it. <<Kalkwasser is made by adding quicklime or lime to water. The Kalkwasser solution is then added to a system as top-off water or in dosing systems. Using Kalkwasser is one method to supplement calcium and alkalinity (carbonate) to your system. There are several reasons to use Kalkwasser: supplement calcium (reef life use calcium so in a closed system with stony corals, calcium is being depleted), raise the alkalinity to buffer the pH in the system and precipitate out phosphate (which is good for algae and bad for reef keepers). There is lots of material here on this topic. Please search and read up on these topics: Kalkwasser, Kalkwasser slurry and top-off systems.>> I was also told by separate source to use Kent Marine Superbuffer-dKH. Will the Superbuffer be sufficient to use. <<Since you are asking about both Kalkwasser and Kent's Superbuffer, I'm guessing that you have an issue with alkalinity and pH. There are pros and cons associated with using Kalkwasser versus a product like Kent Superbuffer. Considerations include cost and simplicity. Using Superbuffer is simple but in the long wrong, more expensive than Kalkwasser or Kalkwasser slurry. Kalkwasser dosing systems can be fairly simple or more complex and of course the initial cost varies. Kalkwasser slurry is very simple but not for everyone. Search and read up on Kalkwasser slurry, top-off systems, dosing systems, Nurce, Nilsen Reactor.>> Of course I know to get salinity right. <<Not a worry. Getting the salinity right is what you already do when changing water. The only difference is you will be using better water in your water changes.>> This ro/di has me all thrown off some, how soon can I add this water to tank. Can I add it as soon as I add buffer and get salt and temp right?<< I hope I have cleared up some of your confusion. Again, RO/DI water is great for replacing water that has evaporated from your system. As make-up water, it goes directly into the tank without mixing salt or buffering. For water changes, RO/DI is much better than tap water. Do what you already do and mix the salt water and let it age before doing the water change. Don't add anything to it. Finally, there are many ways to address alkalinity and pH issues. Don't forget to read up and understand why alkalinity and pH are important to your system. Good luck and cheers - Ted>>

Re: Conditioning RO/DI Water 08/26/05 I have no pH or alkalinity problem. I have had nitrate and brown diatom problems. <<Using RO/DI water is one of the first things to do to combat algae and diatom problems.>> What do you mean by age water? <<Unless you are dealing with some kind of tank emergency and you don't have the opportunity to age the water you should mix up saltwater to the correct specific gravity and temperature and aerate/circulate it for a day or so before putting it into your system. The better salt water mixes contain a buffer so adding a buffer is not necessary.>> So I can take my RO/DI water and put it directly into the tank at temperature without adding anything to it? <<I see from my previous answer, I added to your confusion. Sorry. Yes. Many auto top off systems put RO/DI water directly into the tank. If the RO/DI water feeds a Nilsen reactor, then the addition of buffer is unnecessary. On the other hand, if you store the RO/DI water or place it into a reservoir to feed a top off system, you can aerate and/or buffer the water>> It has very low pH so I figured I would at least use pH buffer for top off water? <<Many people recommend aerating the water to drive off excess CO2 or adding a buffer to RO/DI water to raise the pH before use. You can also make your own buffer using washing and baking soda. Search WWM for more information. Cheers - Ted>> Reg. Dosing Point in a RO Systems 8/25/05 Hi I just wanted to know few things, if you could help me, on a RO System. 1. What Should be the distance to maintain between two or Three dosing points, If I am using Antiscalant, Acid And Dechlorination Before the RO System.  Generally I have dosing Pump to Discharge at 4.0 Kg/cm2 Pressure so I keep the dosing points at The Pre-Ro Micron Filter Inlet Line. <A foot or so would be my choice> 2. Can I Have the dosing before Dual Media Filter/Pressure Sand Filter.? <Yes... given your water/source is not "too bad" such that the interaction of the dosed materials don't cause "too much" precipitation in the filters. Bob Fenner>

High Phosphate in RO water 8/12/05 Hello everyone, I'm a newbie to saltwater and I recently set up a 155 gallon reef tank.  In this time I've had trouble controlling my phosphate levels.  Here are my specs: 1.  155 gal tank 2.  Lightly stocked tank with 1 purple tang, 1 six line wrasse, 1 clown, 1 lawnmower blenny, 2 cleaner shrimps. 3.  2 mushrooms, 2 rocks of yellow polyps, 1 green star polyp. 4.  Two overflow boxes, aqua C ev-180 skimmer which produces lots of crap daily.  I use RO/DI water weekly and perform a 10 % water change every week. My RO system is from Coralife-pure-flo. 4.All water parameters are normal except the phosphate level which is a whopping 1 ppm with the Salifert test! I thought for the last three months that the levels were high because I was feeding too much but I wasn't.  Sometimes I would actually skip a day so my fish could graze on the little hair algae I have in the tank.  I then thought that my test kit was wrong, so I bought a new Salifert test kit.  Anyways, I decided to test my RO/DI water without salt straight from the tube and the phosphate levels measured 1ppm!  I then checked my TAP water from my faucet and it tested only 0.1 ppm.  I retested all my different waters and the results were the same.   I came to the conclusion that it seems like my unit is leaching out phosphate, is this possible?   The RO/DI unit is very new, I bought it 5 months ago and according to the instructions, the pre-filter needs to be changed in a months time and the membrane should last another 6 months.  So I still have time for change.  Any thoughts?  Nilesh <This is an easy one!  Activated carbon is made porous in the manufacturing process by exposing it to phosphoric acid.  If the carbon is not rinsed, it will leach phosphates in high concentration, much of which will pass through the RO membrane.  If you really want a shock, test the water coming directly out of the carbon block pre-filter!  The simplest option is to replace the pre-filters with good quality aquarium brand (something other than Coralife!).  Prefilters should be changed every six months to a year, but the membrane itself should last several years.  Best Regards.  AdamC.>

R/O-DI...HEAD SPINNING - 08/06/05 Hello Guys, <<Morning>> Been reading your site from start for my salt water set up, it's great and I don't know where I'd be without it. <<Thank you, glad you find it useful.>> I am gathering all the components before I start anything.  I want to use a DI unit, my water is well water and very hard.  Iron stains all over the house.  But now I read I may be removing helpful things from my water, is this true?  Please help a rookie in the hobby. <<No real concern here, the DI unit will provide more help than harm.  Just be sure to buffer the output water before use (simple baking soda...or my personal fave, 2 parts baking soda to one part Seachem Reef Buffer).>> THANK-YOU DAN PALMISANO <<Regards, EricR>>

Buffer Dosage - 08/08/05 Thank you for all your help and fast reply.  The buffer you described never mentioned the water ratio, or do I follow the ratio on the Reef Buffer? ""Just be sure to buffer the output water before use (simple baking soda...or my personal fave, 2 parts baking soda to one part Seachem Reef Buffer)"" Thank-you in advance DanP <<I would start with the dosage recommended for the Reef Buffer alone...test this for alk...then adjust as needed.  EricR>>

Aquascaping / Pump / RO-DI / Rock 7/21/05 Real quick (depending on your perspective), a few unrelated questions in relation to planning a step-up from a 20 gal. to a 90 gal. w/ sump) 1.  Is it a bad idea to stack rock directly on the sand bed (obviously, having the typical uncovered bed area in the tank front) in terms of structural integrity (since the bed slowly dissolves, etc.), or would it generally be more advisable to either have the rock  placed on the bottom with sand filled in thereafter around the rock (which I did on my 20 gal., but that seems to require far more rock to obtain nice elevation) or have the rock basically supported independent of the sand via a pvc structure (with the first stackable portion of the pvc support layer being maybe an inch or so under your sand top)? <Best to not set directly on substrates, but either on the bottom or other structure that is stably resting on same> Am I making too much of the dissolution of the sand in relation to the integrity of the overall rock structure? <No, not IMO... have seen some real trouble from the effect of this dissolving... is more of an issue than most all aquarists realize... A bunch of carbonaceous material does go into solution... and differentially... That is to say/warn, that folks ought to add to theirs, perhaps take some out and replace after a year, then every half year or so going forward> 2.  For an external return pump from a sump (let's say, for the sake of argument, an Iwaki or PanWorld), is it ok to have the pump sit parallel to the sump as opposed to perpendicular?  By parallel, I mean the pump is connected to the sump with completely straight plumbing directly into the pump, whereas by perpendicular I mean having a short piece of pipe exit the sump, hit a 45 degree angle and then hit the pump (you probably gathered this without my elaboration on "parallel and perpendicular";)). I would like the to do the later for space saving purposes.  I'm guessing that one turn won't cause much grief in terms of flow to the pump intake, particularly if the sump output is a 1 inch hole graduated down to the pumps intake of 3/4 inch.  Thoughts? <Not a big deal either way... of course, given there is no reduction in fitting, plumbing on the intake side> 3.  In general, and in terms of say "typical" city water (realizing "typical" is a loose, indefinable term), will I gain much benefit from using an RO/DI unit vs. simply an RO unit? <Most source waters, no>   Maybe I'm wrong, but long term it seems as though an RO or RO/DI unit will be more economical than a DI unit alone (such as the Kati/Ani unit (unless you try to reconstitute the filter media, which sounds like a major pain in the rear), a Tap Water Purifier (I've used this on my 20 gallon since the tank requires modest water changes and top-off).   <You are absolutely correct here. Reverse osmosis is the cheapest, easiest means> I think I read in the FAQs by Steve Pro or someone that the small Kati/Ani unit that sells for about $139 can knock out about 200 gallons of purified water (high cost per gallon), and my little Tap Water Purifier can knock out about 30-35 gallons at somewhere around $13 to $15 dollars a filter.  Under those scenarios, and absent trying to renew the media, the little old Tap Water Purifier is more economical than the Kati/Ani unit.  Anyway, I digress.  Do you feel an RO or RO/DI unit will long term be more economical, all things considered, than just using DI units? <RO> How do you feel about the current line of RO/DI units by Kent and Spectrapure? <These are fine... know that they're actually not "made" by these companies...> Lastly, for a 90 gallon tank, what minimum flow rate for such a unit (i.e., RO) would you advise? 30gpd?  60gpd? 90gpd? <Even five, ten gpd will do... given storage of the water... I have a small unit for my pet-fish use> I know that the higher the flow the harder your DI at the end will work as more will make it though the RO, but it seems like a 30 gpd unit will be painfully slow in producing water, particularly if you don't have it plumbed into an auto top off / reservoir fill-up scheme (i.e., just brewing water as you go).  I mean, if a 30gpd unit is really about 24gpd, that's obviously a gallon an hour.  How slow is that?!? <Mmm, not very... really... the oceans were made more slowly...> My little DI unit can spit out up to 10 gallons an hour.... 4.  Lastly, my 20 gal. has some rock in it which has been the subject of a hair algae battle from time to time.  Would it be a mistake to introduce that rock into any part of a new system, even if in the sump or refugium?  Under what circumstances might you make use of this rock, if at all, in a new system?      Thanks for your time. <I wouldn't be dissuaded from using this rock... the "local" conditions... light, predators, competitors, water quality... dictate the life, demise of the algae... Bob Fenner> - RO/DI Evaluation - I bought this unit and will be receiving it tomorrow, I have found 1 previous post about this unit. It is mfg. Water General and it's cost is minimal, it is a six stage unit will you please evaluate and let me know what you think of this unit in comparison to a SpectraPure or Kent Marine.   http://www.watergeneral.com/support/html/RD100.htm <I'm afraid there just isn't enough information there to form an opinion. Most RO/DI units are very similar and vary mostly in configuration from manufacturer to manufacturer. The parts used in each are for most intents and purposes identical. I'm sure this unit will treat you fine. Cheers, J -- >

- RO/DI Evaluation, Follow-up - the question was about the rejection rate in the other post. <I don't see any information there about rejection rate, but four to five times the output volume is not unusual.> But I am just curious if this unit is going to give me quality water for a reef tank. <I'm sure it will be fine. Cheers, J -- >

Confused About Water Hi Crew, Thanks for the work that it takes to maintain such a great site. I am only asking a question because I'm still confused over the water used in water changes. I have a 46 gallon reef tank with only soft corals (mushrooms, xenia, leathers). Before I had any coral in the tank, I used tap water to do my usual 6 or 7 gallon change every two weeks. I try to get 25% changed per month. However, since adding coral to the tank, I now purchase RO/DI water from my LFS, which is a pain. I mix the water with salt in two 5 gallon buckets and add it slowly to my sump. This was fine, but recently another area LFS told me that somehow RO/DI water becomes ??unstable?? after a certain time and that city tap water (properly buffered and dechlorinated) is a better approach. I have no idea what ??unstable?? means. <Me neither... maybe ask for some specifics from whoever is stating this?> Another friend who maintains systems around my area had the city tap water tested twice with no copper or phosphates. He personally keeps a similar size and type reef tank, and does so very nicely. Despite all this, your site suggests RO/DI units for reef tanks, but maybe only the larger systems? <Mmm, to be more accurate, RO/DI is suggested for localities with suspect source water... that is laden with nutrients, possible toxicants as you state above... Many places the tap water is fine... pre-mixed and stored, aerated and heated for days... a week or two ahead of use. You may well be in this category> Some responses state that water you can drink may be fine for a marine system. <Yes> Is tap water without copper and phosphates, yet buffered and dechlorinated suitable for a reef system? <Likely yes> Are there some trance minerals in tap water harmful over time if allowed to build-up? <Almost never... these minerals are "traded out", diluted along with all else during water changes> What am I missing in this water change process? <Mmm, doesn't appear much> And given all the information from all these sources, how should I care for my corals and fish? Thanks for your time! -Mike <Sounds like you're doing fine Mike. Most important element in your success is an open, curious, discerning mind... You seem to have this. Bob Fenner>

Update on Austin water Hey, WWM-ites, <Hello Glen!> I went and got some RO water here in Austin yesterday, and ran my battery of tests against it.  The machine at the grocery store was showing that it had last been serviced on 11-6-04, and the store manager said it wasn't very heavily used.  Based on that limited info, I'm assuming that the media are still in good enough shape to reflect what would happen with an average RO system here. <... not according to the results you post below... something is definitely awry> As I expected, the pH wasn't any different from our tap water.  The RO water settled at pH 10.0 <What? If anything, a functional R.O. device may show a drop in pH (below neutral)... Please see here: http://www.freedrinkingwater.com/water-education2/ro-ph.htm Virtually all bicarbonate and carbonate is removed by reverse osmosis.> on my meter, and a sample of tap water at the house registered pH 9.9.  kH and GH of the RO water registered zero with both the dip-strip and reagent tests, compared to the tap water's 3 dkH with reagent and <75 ppm kH and ~80 ppm GH with the dip strip.  Temperature of both samples was 71F. <This is about right where it should be...> Also, for what it's worth (if it's salient to the total osmotic pressure discussion) the City reports TDS at average 184 ppm in September (the last reported month) and for the third quarter of '04. <Okay> Interesting results - RO here has all the "stuff" removed from it, but still has to be treated fairly aggressively to bring the pH down to neutral, and then buffered to stabilize it (right?). <... should not have to be treated for pH at all... I would check your testing gear (against standards, use other means...)... aerating it should register a near neutral pH over an hours time or so. Does indeed have to have alkaline material added to re-buffer.> Thanks again for having such a fantastic trove of info for those of us who are a bit less informed! Glen

Re: Update on Austin water Not to be argumentative, but 'cuz I truly want to understand... <Me too> I calibrated my pH meter to a 7.01 and 5.01 standard a week and a half ago, and the tank readings have been holding pretty steady (up 0.11 - the tank is just slightly into its cycle - ammonia reading ~0.5, nitrites and nitrates still 0).  The City reports an average total alkalinity at the tap of 60, and a total hardness of 86, which are in line with my not-very-sensitive test kits.  Doesn't this indicate that there isn't much carbonate or bicarbonate to begin with? <Depends on relative measures, what you call "not much"... this is considerable if it is coming out of an R.O. unit, about so-so for U.S. tapwater... and very hard for general Amazonian comparison...> I called our LFS a minute ago, and was told that their RO pH is nearly identical (a couple of tenths lower) to their tap water, at 9.2-9.4 (they draw from a different aquifer, and the slightly lower pH is in line with the City's reports). <Strange... or maybe I should state, unfamiliar to me... our R.O. water has a pH of nearly 7.0, with the source water (San Diego) at 8.2-8.4 most days> I know that y'all's water treatment FAQ says that aeration would raise a slightly acidic pH out of a RO system to neutral, by neutralizing the carbonic acid - will it also drop a pH three points? <Not easily... depending on what (carbonate likely at this high a pH) is elevating the pH, and if there is any alkaline reserve (buffer aka) at this high pH...> If not, does the approach I asked about in yesterday's question (titled "Plan of attack for very soft, very basic tap water") make sense? <Am copying and pasting a pertinent part of this here: "Here's my approach to the water.  Please let me know if there's something I should do differently: 1.  20% water changes once a week, with substrate vacuuming. 2.  Dechloraminate 20-25 gallons at a time (in a dedicated new trash can) - easier and more uniform to treat a bunch all at once. 3.  Bring the pH down to 7.0 (using the sodium biphosphate product (anything better?)). 4.  Boost the kH and GH into more the 125 ppm range using calcium carbonate.  (Would something else, or a different value, be better?  If we actually adhere to this rate of water replacement, does our tap water need additional buffering, or is the little bit that's there going to be enough?) 5.  Aerate and tweak temperature overnight before a water change. 6.  Judicious chemistry monitoring between changes. Since RO water still needs to be tweaked with pH adjustment, buffer, and essential minerals - why not adjust the tap water?  Also, I bet the pH of RO water around here is still quite high, given the tap water to start with - I'm going to get a gallon on the way home and test it. Also, since the tap water is so soft to begin with, the double-whammy of a buffer and an acidic product shouldn't have too much impact on osmotic pressure, right?" This does sound like a logical, workable plan... am still very curious as to what is "getting through" your Reverse Osmosis membrane that is resulting in such high pH though...> I don't mind tweaking the water as necessary, but don't want to osmotically stress the fish. Thanks again for your time, Glen <You are right to be concerned re osmotic shock... Do me/us a favor and call your water supplier (their phone number will be on the bill they mail you) and ask to speak with someone in water chemistry there. Please explain what you have here, and ask what they think is going on with your resultant pH. Bob Fenner>

Re: Austin water dept. chemist discussion Well, that stumped 'em. <Umm, me too... maybe we can start a club...> I talked to the City's chemist, and he was surprised as well that the pH stays that high after reverse osmosis.  He said that the output of their deionization system (when they make their reagent-grade water) gives them a pH of 5.5 to 6 (as it's supposed to). <Yes, agreed>   He said he's not intimately familiar with how RO systems perform here, but he doesn't see any reason why the RO water still carries such a high pH.  His guess was that given the high concentration of hydroxyl ions, it's possible the RO system is being overwhelmed, and suggested that someone test the very first dribble out of a new RO cartridge to see if it reads closer to neutral. <... hee heee... am given to suggest that your source water has a good deal of "hydroxyl" ion concentration... turns out that most brand X R.O. membranes allow ethanol/C2H5OH (and Glycol if interested) through... do you feel elated after a big glass of tap? Hey, maybe that's why it's called a "tap?". Just joshing here... and things change... I was a H.S.... Physics and Chemistry teacher years back... but OH's (Hydroxyls) are otherwise given the suffix "ol"... as in alcohol...> The chemist also said they treat the water at the plant with calcium oxide to cut the sources' hardness from 185-200 down into the 85 range.  That explains why our tap water doesn't fit the usual high pH/hard water "norm" - it comes somewhat pre-softened.  From the reports, the source water is also around 170 ppm kH, where the tap is down around 60. <Ahh, yes> I called the LFS again and they said their RO water always has a pH above 9, though they've never tested it's initial output.  Another LFS backed up the tale - RO pH is never below 8.5, and almost always over 9. <I believe you, them... am just at a loss to explain why/how this is happening. Hopefully some kindred chemistry soul will see our correspondence posted on WWM and chime in> All the more reason to be religious about water changes, and not put in more additives than absolutely necessary, huh?  Thank goodness for a wife who's interested in aquariums, too! <You lucky pug! Mine is kind enough to go and photograph on dive trips, even liveaboards, even though she is easily boat/motion sick> Once again, thank you for your site and your input.  I really like your rational, cautious, livestock-oriented approach to the subject. Glen <Me too! Be chatting, Bob Fenner>

Water change First of all, I would like to say, this website has been a HUGE help to me, but also a little scary....as they say, ignorance is bliss.  The more I find out, the more I feel like I don't know.  That "snowstorm" phenomenon...I had nightmares.  :) <These will soon cease my friend> Here's some background on my tank. 65 gallons with 4 inch sand bed and about 45-50 lbs LR 1 star polyp, 1 frogspawn, 1 plate coral, 1 mushroom rock fishes are (all are pretty small): pygmy angel purple tang algae blenny niger trigger yellow Coris wrasse maroon clown Sri Lanka Dottyback <All this crowded into a sixty five gallon tank? Will become more so with time...> water parameters: 1.024-1.025 SG at 77 degrees F calcium 400 phosphates < .01 nitrate <20 nitrite 0 ammonia <.10 pH am 8.0, pH pm 8.1-8.2 alkalinity 3.2 meq/L 2 pumps with 300gph circulation each Prizm protein skimmer (if you can call it that, looking to upgrade to AquaC) <Hee hee, good idea> Filstar canister filter (mech. filtration, nitrate sponge, Phoszorb, Biochemzorb) I do 10 gallon water changes bi-weekly. All corals and fish are doing fine.   My tank has been set up for 2.5 years, and this is the first water change I am doing with a buffer added to the water.  In the past I used RO water, and salt (of course) heated it up, aerated it for 24 hours and poured it in.  And I have been wondering why I have had a low pH for so long...Here is what I have done so far.  Set up the water change tank with just the RO water, and aerated/heated it for 12 hours.  Added 1 tsp (10 gallon tank) of Marine Buffer.  Aerated/heated 12 more hours.  Added the salt (Oceanic) this morning (to 1.024 SG) and went to work.  When I can home, the water was cloudy.  The pump I use for circulation/aeration has a white substance on the intake.  What I need to know is can I use this water for my water change? <Yes, the precipitate is harmless>   I have added this same buffer before to my main tank diluted in a cup of water with no cloudiness, but I have never seen my water change water cloudy before.  Thanks for any advice you can give me. <Likely a simple alkaline earth and alkaline reserve reaction... hard to get both high calcium and KH/dKH. Bob Fenner>

Re: water change, Clown-Coral interaction Thanks for the response, I appreciate you taking the time to answer my question.  Unfortunately, the precipitate made me nervous so I dumped the water and started over.   I did the same procedure as before, but added 1/2 tsp buffer and the prescribed amount of pro buffer to bring pH to 8.4 and alk to 3.2meq/L.  I don't currently have a calcium test (mine expired) so I don't have a reading there.  One is on the way.... <Okay... very likely whichever brand synthetic mix you are using, the calcium will be fine.> You mentioned that it seemed a lot for my 65 gal tank, what about it seems like to much.  Too many fish, or too many coral or both.  What would you suggest, I really thought it was the right amount, but your advice would be appreciated. <Too many fishes... when they grow, there will be issues of inter-species antagonism, as well as pollution from food, wastes for your cnidarians> Another question, does the clownfish bother the plate coral? <Can, yes... some Clowns are so aggressive in their pairing with non-anemones that they do cause real damage>   He seems to like it a lot and is always swimming in it, and bumping it on the sides and towards the bottom, just like he would an anemone.  The plate coral seems to be affected by it, but not too negatively, but I am still not sure. It seems that the clownfish could injure some of the lower tentacles if he bumped them against the "plate" of the plate coral.  What do you think?  The LFS said it would be fine, but you know how that goes.... <I'd just keep an eye on these two> Thanks so much for your time! <Thank you for writing, your concern. Bob Fenner>

Finding a 2-column Deionizer 11/8/04 Anthony, I am trying to decide on a RO/DI product. You said to look into a 2-column deionizer as a possible choice. I have not been able to locate a manufacturer or distributor for this.      Do you or can you give me a short list/recommendations for these?. Thanks Keith                                                              <a simple keyword/phrase search on google for "deionizer, aquarium" and like entries will yield good leads my friend. Any of the big mail order companies too carry deionizers: Marine Depot, Custom Aquatic, Drs. F&S, etc. The brand I have used for years is "Kati Ani" from Germany. Anthony>

Google, Google, Google till it hurts! Kati Ani dealer 11/9/04 Hello All!! <howdy> Anthony, in response to a deionization question yesterday you mentioned that you personally use the brand Kati Ani from Germany.  Are you referring to Kati Ani generically or is that the actual brand name.  I asked because I have seen many other recommendations on this product before but cannot find a distributor or a manufacturer's website.  I believe it is made by AquaTech, but I cannot fine their website.  If you have any info to point me in the right direction I would be quite appreciative. Thank you kindly, Corey <my apologies for the title to this e-mail, my friend... but I am rather frustrated today - feeling like an enabler - with friends/queries from folks with seemingly little effort to do a simple keyword search to help themselves <sigh>. To help you and illustrate a point... in response to your question, I simply went to the google search tool which is plastered all over our website and well known at large. I typed in "Kati Ani price" (three common words that would appear on a page with this product if it existed out there somewhere)... and the very first page that came up has a link to: http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4499&N=2004+22789 ironically... this merchant is also an advertiser. Our only advertiser on WWM at present: Drs Foster and Smith/LiveAquaria.com I'm sure there are other merchant of this product out there... google till it hurts, bro. Anthony :)>

Google searching/ Kati Ani 11/10/04 I sincerely apologize for your impending frustration at my question on a Kati Ani unit.  The site (Dr.FosterSmith) that you recommended I had found before querying you. I did and do search my brains out on google.  I have seen numerous units using Cation resin and Anion resins.  That why I asked if you meant Kati Ani generically as a type of unit not a brand.  I was just unsure which manufacturer you use and recommended.  Again I am truly sorry for the perceived irritation and I am grateful and understanding of the work you and the crew put into the site <no apology needed, my friend. If any, its me being grumpy/frustrated with the instant gratification society we all live in :p On another day with less mail and more sleep, I would have been a much nicer fellow <G>... making jest or at least handling it with sarcasm :p Best of luck/life to you... and thank you for understanding, mate. Anthony>

Water filtration/de-mineralization 11/6/04 Hi Crew- <howdy> I let my R/O membrane dry out by accident, and I was wondering if R/O is even necessary for me.   <hard to say, but likely not. You can compensate in the tank with other mechanisms for good nutrient export (skimming, Chemi-pure, PolyFilters, water changes, etc)> The amount of water that is wasted disgusts me.   <do consider a 2-column deionizer instead. No waste water and same or better demineralization than R/O> I have kept the first 2 stages(3-stage Hi-S) and diverted the membrane  input to a tap water filter.  My water supplier lists tested nitrates at  .05 PPM. <Yikes! Is this even legal in your town? Not so in many across the country. My advice is to consider a deionizer like Kati Ani for controlled, quality source water. Best regards, Anthony> <<Likely the decimal place went unseen. RMF>> R/O vs. DI 10/23/04 I look to your website for all of my information.  All your articles  and  FAQ's are invaluable, and I thank you for providing this service. <thanks kindly for saying so> I let my R/O membrane dry out (oopsie) while reconfiguring my reef  set-up.  A new membrane is about $90.  I saw a DI unit, namely the  Deion 200R, for about $200.  It claims that it wastes no water- needless to  say it caught my eye since my Kent R/O throws away 3 gallons for every gallon it  makes.  Hurts the wallet when the water bill comes. <agreed... and is simply wasteful at large. I prefer DI myself> Is this DI unit suitable for a reef tank?   <likely yes... but do ask to see the specs> If I'm going to spend 90  bucks, might as well spend a few buck more and save in the long run. <agreed. And do a keyword search for "DI" from the home page at WetWebMedia.Com for more info> Again, thank you for both your service and time. James Pruefer Prov, RI <all good... best of luck! Anthony>

A new 6 ft. marine setup hi bob <Andy> I wonder if you can help me. <Will try> I currently run a 3ft marine reef tank, due to a new extension my wife has agreed to upgrading to a 6ft! <Congrats!> I currently buy R.O water from my LFS and change 20% every 2 weeks. <Good exercise... but I'd buy, fit one of my own> This is fine but I would like a simpler solution as I will obviously be doing bigger water changes! <Yes> I don't really want to run an RO unit as I believe they have to be running constantly? is there any way of creating marine friendly water as and when I need it? <Mmm, look into these devices... they are exceedingly simple... most have a reservoir tank this has a pressurized bladder... Reverse osmosis "shuts itself off" when the tank/pressure is full> any advice would be helpful. <Investigate, get one of your own> whilst I'm emailing  maybe you could also suggest the best way of setting up a sump for this size tank. I don't currently use one with my 3ft but am lucky in that my LFS will make a tank/sump to any spec. I was looking at setting up with a 6ft tank with a weir, how many compartments would I require for the sump? and what sort of size sump would you recommend. <This is posted on WWM> hope I'm not asking to much! thanks Andy <Study my friend. Bob Fenner>  

If only I could start over Hey WWM Crew, <Hi Jim, MacL here with you today, how's life?> Ever since I stumbled onto your site it's been hard to break away. I'm learning so many new things. Unfortunately I'm learning I would have done almost everything different (equipment wise). <Every time I read something new I have the same thoughts if that helps? My tank is never sparkling clear. I have tried Purigen and use Chemi-Pure. After reading hours of articles from your site I think RO water might help me out in many ways. (clearing up my water and keeping the water quality high). Here is my question: I have read every article on RO water that you have to offer. The problem is now I am more confused than ever on what may be the right one for me. A RO unit, RO/DI unit or a Kati & Ani Ion Exchange unit (which I'm not even sure what that is?) I don't want to spend a ton of money but my bigger concern is that I don't have a lot of room. I have a cold water valve in my tank room but no drain. <You have to have some way to drain the waste water off, so would have to use buckets or hosing to take it to another area.> So would that rule out a RO unit due to water waste? <Another option might be a U.V. sterilizer for water clarification or a PolyFilter strategically placed. Lots of people keep their Ro or RO/di units in bathrooms and use buckets to move the water down to the tank depending on the distance to the tank. Personally I prefer the RO/DI units for a more clean water. MacL> Thanks again for all your help!! Kati Ani deionizers... DIY units 9/20/04 Anthony, I know you like the Kati  & Ani units for water purification. <yep been using them for over 10 years> I am trying to locate a Kati & Ani 2 but am having no luck. Dr. Fosters only have the Kati 10 but have the Ani 2. I did a search on Google but couldn't find anyone else that sells the Kati & Ani units. Any ideas? Thanks Pat <no worries... better still is the bulk resin for DIY canisters or Kati Ani replacement. Spectra-pure sells them at: http://www.spectrapure.com/St_replac_p5.htm best of luck, Anthony>

RO/DI or Kold Ster-il 9/8/04 Thanks, Bob - <Anthony Calfo in his stead> I guess I'd also like your opinion as to the quality of water produced by the Kold Ster-il vs. the RO units, please. Dave Parker <hard to compare... apples and oranges really. Kold Ster-il produces highly filtered water... but does not demineralize like RO or DI. Some people have decent tap water with desirable mineral content... just in need of cleaning up some of the nasties (chlorine, phosphate, etc). For such situations... Kold Ster-il is excellent. But for worse source water (quality or variability of composition) or for aquarists that simply want better control over the water used/produced... then demineralizing and then buffering back up (with desirable elements of hardness) is the way to go vis a vis RO or DI. I personally favor DI as there is no waste water produced and the recharge chemicals are dirt cheap and be neutralized to inert so to speak. RO instead wastes a lot of water with even expensive units and the cartridges are an ongoing and considerable maintenance expense. Best regards, Anthony>

RO/DI or Kold Ster-il 9/8/04 Thanks, Anthony, <always welcome :)> If I understand, I can produce top-quality water, then using a Kold Ster-il followed by and add-on DI stage, and produce no waste water.  Is this correct? <hmmm... my apologies. I may not have been clear. The first thing you need to decide on is whether you need ultra pure (ala distilled) water from an RO or DI that you are willing to NEED to aerate and buffer before every use. This is the most work on your part, but produces the most reliable, clean water for evap top off or for salting for marine use. But it is dangerous to use raw untreated (unbuffered) DI or RO (or distilled) water. Yet... this is what many aquarists choose to do, myself included, to insure superb source water. Kold Ster-il units on the other hand do not demineralize water but leave in Calcium, Magnesium, etc. They are basically top shelf chemical filters that clean up the water quite a bit... but do not reduce the conductivity/hardness, etc. It is an outstanding prefilter for a DI... and if your tap water is not too bad... can stand alone without even needing a DI or RO. DO test your tap water to see how bad is bad first. Ultimately, the Kold Ster-il  + DI units an excellent choice in my opinion> thanks for bearing with me, Dave <no worries. Anthony>

RO/DI or Kold Ster-il II 9/8/04 Thanks again, Anthony, <cheers again> I always aerate and buffer with SeaChem Marine buffer before adding my salt - I happen to use Oceanic if it matters.  I understand about not using distilled or raw, RO/DI as top-off - heck I don't even do this for my goldfish tank.  I'm simply looking for a way to produce top-quality water for this process without wasting 4x what I produce, <ahhh... definitely DI then for you> and to be able to produce it more on-demand since no one is home during the day to watch the RO unit overflow my Rubbermaid cans. <no worries... you will have this with DI. But with either... there is always a simple float switch for your reservoir> I have a whole-house water softener, so that much waste water gets expensive, and I believe (correct me if I am wrong) that my water softener will take a lot of the calcium and magnesium, in particular, out, but leave some sodium (or in my case, potassium) in.   <yes... true. Salt softeners are NOT recommended for use with aquatic life. Long term problems with water quality> Do I need ultra pure?  Well, I get algae blooms like crazy using tap, that is why I started hauling RO from my LFS. So I guess I may not have been clear, either - I want to produce top-quality raw water, with as little waste as possible, and am in the practice of buffering and aerating and buffering already. To ask the question another way, what am I likely to leave in my water by using Softener -> Kold Ster-il -> DI stage vs. having an RO unit in the middle, and is this difference enough to cause problems down the road. <just use the Kold Ster-il & DI stages... never the salt softener> Appreciate the help and advice, Dave <best of luck, Anthony>

RO/DI or Kold Ster-il Hi, Gang and thanks for a great service!  I am setting up a new 120gal FOWLR, and am getting tired of hauling RO water from the LFS. <I hear you... my arms are a good inch longer from hauling water about all these years> I'm ready to put in a system myself.  However, I am scared by all of the waste water the typical RO/DI units produce, as water is not cheap here. <Mmm, I divert the "waste line water" to my pond outside, and in turn to the garden> I've heard about this Kold Ster-il unit, and that it does not produce wastewater.  Can you help me understand the difference in the processes, and perhaps suggest which might work best? <This unit uses filtrants that are not re-used... contactors... so all water that is filtered, passes through the unit is used. RO utilizes selective membranes capitalizing on ambient or increased pressure to "squeeze" water molecules and exclude solids (and their zones of hydration) and some other liquids, gasses from getting through the membrane... with their water periodically bypassed to waste> Either system would come after my water softener, and in this, I use potassium chloride rather than sodium chloride as the agent to wash/renew my resin bed.  Thank you for your input! Dave <The real (IMO of course) difference in practical terms are the upfront costs of the two types of units/technologies, versus the amounts of waste water generated... Both will produce high(er) quality water of use. If it bothers you to "throw away" so much RO waste water (a ration of 4-5 to 1 of usable is not uncommon) than I would go the contactor route. In all fairness though, do take a look at your water bill, see how much water is going for other uses... Bob Fenner>  

Buffering Hi Scott <Hello again!> How are you? <Just fine, thanks!> I need your advice on my thoughts. I pre mix my tap water with salt as I do not have an RO-unit. I leave this mixing for a week before I add the new water to my tank. I was thinking will it help if I were to add crushed shell to this drum of mine and then mix the water in there. <I would not bother, myself.> Will this maybe assist me in pushing up my ph instead of using additives and adding bi-carb  which I ain't really too fond of, like to keep it as natural as possible. <Well, most of these buffer products are quite natural, actually. A great assist is a deep sand bad of aragonitic material> Also what exactly is KH and how do I go about maintaining this , have seen some fancy, costly additives which I personally don't think are necessary. Please shed your very valuable advise on my thoughts Thanks Again Ziad <Well, Ziad- rather than go nuts with a long winded dissertation on this basic tenant of water chemistry, I invite you to check out the large amount of information that we have on this subject on the WWM FAQs. Simply use the Google search feature that we have here, using "KH" or "alkalinity", or "buffering" as your key words...Enjoy the learning- the answers are here in abundance! Regards, Scott F.>


Buffering (Cont'd.) Hi Scott <Hi there!> Thanks for your input <You're quite welcome!> can I try adding crushed shell to my drum where I mix my water to push the ph of my tap water up? <You could> Do you think it will help <Personally, I don't know if it will have much impact on water chemistry, as this material will dissolve very slowly-over time. Makeup water will generally not be in this drum long enough for the material to have a meaningful impact on water chemistry, IMO> Thanks. Regards Ziad Limbada <Always a pleasure! Scott F.>

Deionizer or R/O Unit? Hi, I am in the process of setting up a 75 gallon salt water F/O NLT aquarium. I would like to know if deionized water is OK for this setup, or if I need R/O water. <Deionized water is fine, in my experience> I do not have any place in my house to set up a large unit and would like suggestions on what type of units you might recommend that would provide good enough water quality for fish only, be fairly portable and fairly inexpensive to purchase. I have considered a bare bones unit by Kent.  Any suggestions you may have would be greatly appreciated.  thanks, James <Well, James, Kent does make a fine deionizer unit (I think it's called "Deion 2000" or something like that). Other manufacturers, like Spectra Pure and Captive Purity might, as well. The "Kati/Ani" units are great, too. All of these units tend to be a bit pricey, but they are well worth the cost, as they are efficient and don't waste water! Good long-term investments! However, most commercially available RO/DI units are just fine, too. Regards, Scott F.> James Hall

Re: Planted Tank Water for Sea Salt Mix?? Thanks for your time and advice.  I'm attending the FINDIG in October (hosted by the Sacramento Aquarium Society) and will purchase a R/O unit there.   <Ahh! A very nice get-together. I gave a pitch there last year> I think a 50gpd unit sold for $35.00 in the raffle last year, I can afford that. Thanks Again for your time and the time you save us with your knowledge. Jose Saldana <A worthwhile investment. Hope to meet you about. Bob Fenner> - Water Storage - Hi crew, I'm in need of more help yet again! I use a 40 gallon trash can to make up my saltwater.  My RODI water goes directly into it.  here is what I noticed, RODI water test at 1-2 ppm when tested directly in a clean glass, however when the water has been sitting in the can for a day or so with the pump running the water test at about 35-40ppm. <PPM of what?> I recently cleaned my garbage can with a solution of vinegar and water to clean out a white substance (calcium?) that came out of solution from my previous make up water.  I only rinsed the can out with water.  Should I have used something else to completely clean the can? <No, the vinegar should work just fine.> what could be causing the raise in ppm? <Hard to say without knowing what it is that you are measuring in parts per million exactly.> I have a second 5 gallon bucket that stores fresh RODI water to be used to top off of evaporation water, there is a small powerhead in this 5 gallon can.  I tested the water in their after it had been their for about 4 days with the powerhead and the water tested at around 650ppm!  These cans have only been used for my fish tank. Is it possible because both of these can are left outside, that the water is getting polluted, I keep covers on them, but of course it is not by any means air tight.  Would it help to move these cans into my garage? <It's worth a try.> I appreciate your thoughts, thanks. <Cheers, J -- >

- Water Storage - sorry, I am simply measuring total dissolved solids using the water tester that came with my RODI unit, the RODI produces water at about 1-2ppm, however, my stored water is anywhere between 35-650 after running with a powerhead for a few days.  any ideas based on the new information about what I am measuring... <Most likely dust and particulates from the air - you did say these containers are outside and not tightly sealed. Cheers, J -- >

Do I Really Need an RO/DI Unit? Hello.  I am new to saltwater but have had freshwater tanks for around 5 years now.  I have found that my tap water is just not cut out for saltwater in that my tanks  (72 gallon and 18 gallon) turned pea green literally overnight within a week and a half of each other.  I have tested the water with ammonia, nitrate and nitrite all at zero.  My pH is 8.3, salinity is 1.023.  In researching your site, I found only one post that referenced something called an Omnifilter and it was made in passing.  I have purchased an Omnifilter system and the filter cartridges that I am have are a string wound whole house filter that is rated at 5 microns (first in line) and a carbon filter that has a rating of 2 microns (second).  I am wondering if filtering my tap water through this system will take care of getting rid of the chlorine and chloramine for use in my tanks without the use of a dechlorinator. << I'm not sure, but to me, using carbon is good enough for chlorine and chloramine removal.  Also, if you let the water sit out after the filtering for 24 hours, you should be fine. >>  My thought was to try to reduce the amount of silicates that are in my tap water and increase the quality without going to a full blown RO/DI unit. << I think that is a good move.  Obviously RO/DI is a great way if you can afford it.  Keep in mind many many many people have great looking tanks with tap water.  However, they also have great filtration and lots of corals. >> Michelle Peralta <<  Blundell  >>

- Choosing an RO/DI Unit - Good morning folks. Thanks always for your site - it is great. My question is what in your opinion is the best ro/di unit available today for ease of use, results, quality, and long term costs of use. <I'm not sure there is a "best" - for the most part all units use the same basic parts and really the differentiating item that influences the price is the number of gallons per hour the unit can deliver.> I really do not care what initial costs are. My aquarium is 300 gal. custom fabricated (=I built it) although not yet up and running. There appears to be several on the market. Also, any thoughts on size? <Whatever fits your needs.> Thank you - Chris <Cheers, J -- >

- Buffering RO/DI - Hi, Hope all is going well for you there.  I have a couple of questions please.  First, I use D/I water which I store in a 50 gallon plastic container.  I have read that R/O water should be aerated for 24 hours before adding the salt mix.  Is this also true for D/I? <Yes.> Also, I use Seachem's marine buffer.  Should I add this to my water before or after I add the salt? <Before.> And lastly, what action can I take if a particular batch of salt mixes to a higher than normal ph? <Limit the amount of buffer you add before you add the salt.> I use instant ocean, and have read that at times it can mix to higher ph than normal. <More likely due to differences in the source water and not the salt itself. Test everything before you make additions.> Thank you for your time, James <Cheers, J -- >

- RO vs. DI - Hi, hope all is going well there.  Please clarify something for me.  I had planned on getting a Kent's "bare bones" R/O unit, but recently read that if water is only R/O treated and not R/O AND D/I it can still cause problems in the aquarium. <Is this specifically related to silicates? If so, the presence of these is often overrated and blamed for Cyanobacteria outbreak. Problem algae can be avoided by means other than source water, especially if the silicates are reasonable.> Please let me know what you think. <Really depends on the quality of your source water. RO/DI will leave your water stripped and demineralized and then the water will need supplementation to make it suitable for saltwater - for instance adding buffers. If and unless your tap water is complete junk, RO usually does the trick.> thanks, James <Cheers, J -- >

- Bare Bones RO - Hi, I have a 75 gallon F/O tank.  I am considering buying one of the Kent Marine Bare Bones R/O units.  Please tell me if you know anything about them. <Yes, I know a thing or two about them... was there a specific question?> Also, I have never owned any kind of R/O unit.  Are they hard to assembly and/or use? <Should come out of the box ready to use.> thanks, James <Cheers, J -- > - Bare Bones RO, Follow-up - could you tell me if they are a good quality product? <For the most part, the majority of RO membranes are created equal. You will get good performance from this unit. Cheers, J -- >

- Bare Bones RO, More Follow-up - I have read that if water is only purified through a R/O unit and not a R/O / DI unit, that the water can still contain impurities. <Is one way to look at it.> Please explain. <Please read here: http://urila.tripod.com/ and here: http://chemistry.about.com/library/glossary/bldef52900.htm > I also would like to know the difference between R/O and D/I. <Read up. Cheers, J -- >

- Reverse Osmosis Questions - Hi how are you I had a couple of questions with regards to R/O water. <Ok.> I would like to know which tests I should perform on R/O water (without the salt added) to know that the membrane is functioning properly <There is only one test for RO that I am aware of available to the hobbyist - TDS, Total Dissolved Solids. Typically available as an electronic device.> I figure I should test for PH and GH is this right? <Mmm... not sure these will tell you if the membrane is working correctly or not.> if so what should the PH and GH be for freshly made R/O water? <GH wouldn't be influenced very much by RO alone unless you added deionization. pH likewise will be influenced by the GH although the removal of some other compounds by the RO would likely change the pH somewhat. I have no idea what these values "should" be as they will be different with each source water. With DI added - the pH should be in the 7.0 range.> I was told that if your PH and GH rises this means that your membrane would soon need to be replaced. <Could also indicate a change in the source water.> also should I use those R/O right additives (Kent) to the water which claim to make the water ready before adding the salt. <Again, strictly RO water without deionization typically doesn't need the same type of replenishment - it has not been severely demineralized. Would test the output water first, and then supplement as needed - as indicated by the tests.> I know how to prepare R/O water for the marine aquarium, I would like to use it for my freshwater aquarium also, how do I prepare the water for freshwater use is it the same as saltwater minus the salt? <You may need to add something to reduce the pH - of course depending what that is - you've not mentioned any specific numbers so it's hard to say specifically what you might do.> my last question is that my salt tank is now 5 months old and I cant seem to get rid of my algae problem, it is brown and somewhat golden in appearance any suggestions or will this disappear with time. <Is likely Cyanobacteria and is typical in new tanks - you must get in there and remove the stuff - it often will not go away on its own. Please read here: http://www.wetwebmedia.com/bluegralgae.htm > thanks very much for your help. Val <Cheers, J -- >

Abbreviations (6/20/04) Awesome, thanks for the advice, I plan to use it. <You're welcome.> Sorry for the stupid question, but what does RO, and DI mean? <Not stupid at all.> I'm sure it'll be obvious once I get the answer, but I saw on the website and message below, but have never heard before. <RO=Reverse Osmosis add DI=De-ionized; The DI is a further step after RO or a method by itself that leaves the water even more pure than RO. Using strictly DI wastes no water, while RO wastes 4 gallons or more of water for every gallon of purified water produced, depending on how bad the water is to start with. Much more info on WWM water FAQs. Steve Allen.>

RO/DI units 6/11/04 Hey Crew, Good morning to you. <to you in kind> I had a question on RO/DI units.  I found a unit made by WaterGeneral Mfg. Co. (Aquarium 110GPD RO+DI Reverse Osmosis Filter).  Have you ever heard of this product or company?  The unit is half the price of comparable units.  I want to save money, but not at the expense of quality. Thanks, Pete C. <I recommend DI units only... RO units necessarily waste a lot of water. Do ask this mfg what the reject ratio is from the RO. Chances are that it is 4: 1 or worse... meaning that 4 or more gallons of water are sent down the drain to make each gallon of purified water. Let me suggest you look into buying a proper 2 column deionizer instead (Kati Ani brand instead). Anthony>

- RO Setup - Good day!  I am kinda confused about how to figure out which end of my RO system to run into my sump for an auto top-off system.  The 5-stage RO Sx. has a line coming out of the fifth stage into a 4 gal. Holding tank, another line coming out of the 5th stage into a spout. <I'd say out of the fifth stage.> Which one of these do I connect into an auto-top-off system in my sump?? <The final stage in the filter.> It is rated at 85 gpd, but it seems to only draw water out of the tank when the spout is open, otherwise the flow is very slow. <Best to test by trying to fill a known volume - say a trash can. May be a factor of existing tap water pressure.> Thanks in advance for your help.  Your site is AWESOME!! Ed <Cheers, J -- >

Pickle Barrel Water Change 5/30/04 Thanks, again, Adam.  I will clean barrels w/baking soda next time. <Do also consider Arm&Hammer Washing Soda.  It is in the grocery store near the laundry detergent.  It is perfectly safe to use (fairly pure NaCO3) and does not contain any soap or detergent and is a bit more aggressive than baking soda.> Anyway, matey told me we have used stored water in these drums before w/no ill effects, so we're going to use water & do change tonight.  All parameters are same as aquarium.  I buffered the water, aerated it and cured it; hopefully all will go well. -Kathy Harper <Best of luck!  Adam>

- RO vs. DI - Hi Gents, I am in need of some education! <Me too.> I have a 70 gallon reef, 30 gallon sump, and just added an AquaSpacelight with 650watts.  So, I had to remove the hood and tank top covers, and as the summer hits, that water is leaving fast!  I'm probably going through ~10 gallons a week through evaporation.  The tank is doing the best it ever has with this setup and RO from LFS currently, lots of buckets. I also am using an Aqua-C EV-150 and DSB.   I have been successful (knock on wood) with Acropora, scallops, Gorgonia, some other SPS (not sure what exactly it is), a small polyped cup, plates, brains, and some Ricordea, orange/red/green polyps and other misc. non-stonies. Ok, to the question: I was about to buy a Hi-S 35 or 60 gpd RO/DI unit by Kent, then I reviewed all of your FAQs on this subject and have seen several different options, and opinions.  I like RO because it can get the water so clean and it has worked excellently so far, but I hate wasting that much water. <Then store the water - what comes out of the waste side of the RO is dechlorinated, and pretty much safe to drink. Save for watering plants or for use around the house. No one says you have to throw it away.> I don't know enough about De-I units to make an educated decision, and there doesn't seem to be much info on them out there, but some of you really like and have promoted their use.  Please help me understand the basic differences, and their advantages/drawbacks. <DI units are exactly that, and not much to explain - just a deionization cartridge.> How do you re-use the de-I units---do you have to replace media often? <That is the Big Deal (tm) - DI cartridges can be renewed but require the use of some hazardous materials. Personally I'd just swap out the cartridges - and how often will depend on the quality of your source water.> Can the De-I units get the same quality of water as an RO unit? <Really, defend types of filtration - suffice to say that the product water from each is "clean" but cleaned differently.> Is it good to run either RO OR De-I and not both together? <You can run both together, and this is not an uncommon configuration - I own an RO/DI filter, but no longer run the DI cartridge. DI after RO tends to deplete a good portion of the minerals in the water. Where I've been living for the last couple of years, the water is very hard, so I take advantage of that rather than having to re-add compounds that my water filter has taken out.> I understand that they're both options, but don't understand what to base my decisions on. <I'd work from the quality of your source water - if it is even close to good, you really can get away with throwing in some dechlorinator, mixing for a day or two and then adding salt. Heavily treated water or water high in particulates may need additional filtration.> Sorry for the vague e-mail, but I just haven't found enough info to make it a more educated question!  Any help would be greatly appreciated. (and if there is anything else you think I should change, please let me know!) Thanks, Scott <Cheers, J -- >

- RO vs. DI, Follow-up - Ok, a follow up question... I think I may have come up with a solution--maybe! <I may come up with an answer, maybe...> I dislike all the water waste of RO and can't really save it for later use, and don't want to remove all the "good" things in my water as it is very hard and of good ph.  Can I get two "add on" RO canisters, and only use a sediment filter and a carbon filter---no TFC or DI? <Sure.> I would like to know if that would take out some of the bad things by using the carbon and sediment filters, but not waste water due to not using the TFC filter, and also leave a lot the calcium? <Would take care of some of the particulates and chlorine.> If so, what else would this leave in my water? <Hard to say... would need to have the output tested to be certain.> Any good points or bad points to this proposition? <Not really.> Also, what kind of carbon filter would you recommend--1, 5, or 10 micron? <Slightly smaller than the prefiler you choose.> Or is this a waste of money and I should just leave everything in the water and dechlorinate it? <I'd try this route first if your source water is of decent quality - do you drink your tap water? If so, it's probably ok to use in your fishtank.> If the latter is your suggestion, can you recommend a good dechlorinator which won't set my skimmer on the fritz? <They all do this to an extent, and there's no real way to remedy it - have heard that Amquel does OK, but am not certain that it is a dechlorinator - check the bottle.> Thanks again, Scott <Cheers, J -- >

Tap water quality improvement Hi Robert, great article on water quality.  I'm just getting back into marine aquaria again and have a question regarding water. As usual, water here in Victoria B.C. Canada is chlorinated, no surprise here !  Would a 3 or 4 stage reverse osmosis system solve problems with chlorine and other crap for a marine fish tank water changes ? < An RO unit removes almost all the minerals from water including chlorine. It is so pure that you would have to add everything to make it a complete saltwater mix.-Chuck, Sorry, Bob was unavailable to answer your question.> 

Buffering RO/DI water 5/27/04 Hi Marina, <Anthony Calfo instead> Is the Kent Marine Pro Buffer dKH sufficient to reconstitute RODI water?  <most any common sea buffer will work fine. Do aerate in advance to reduce the amount of buffer needed> Or should I be looking at another product.  <I personally like Aquarium Systems SeaBuffer and most any SeaChem products. I've never been a fan of Kent products> thanks, I understand you are shorthanded, so I will wait patiently for a reply (well at least I will try to wait patiently:) thanks for your support. <best of luck, Anthony>

Eliminating Undesirable Compounds From Source Water (Pt. 2) Scott - Thanks so much for the information and especially for your time. <Glad to hear that!> Will look into the RO unit. Based on other things I had read, I had already decided never again to add trace minerals to the water, which you just confirmed to me. <Only if testing determines a need!> So if we get the source water situation straightened out, we should be in good shape. Would have never occurred to me that it could be the source of the elevated nitrates.  <An often overlooked cause of persistent nitrates in aquariums!> You have a great service here. Have a wonderful day. <You, too! Regards, Scott F> 

Can I add on a D/I cartridge? What an education I'm getting, reading all the FAQ's! Thank you, all of you. Question: I have a 3 canister Pinnacle RO unit, and after reading until my eyes crossed about the benefit of the D/I also, want to know if I can just rig up a deionizer unit in line with the RO unit I have? If so, how?? < There are many commercial units sold with a DI attachment added at the end of the RO flow. These give you ultra pure water that is probably way more than you need. Check out the Smiths and fosters website and look at the RO units and you will see what I mean.> Another question--I forgot how cold my garage got in winter, the Pinnacle froze, cracked some canisters (since replaced), but I'm not getting much of a flow at all--lucky to get 3-5 gallons/day. I'm replacing the cartridges tomorrow (they are in moderate usage about 7 months) to see if that's the problem, but if flow is not enhanced, could the freezing have caused the membrane to malfunction?? Thanks for all the informed information...Barry < Freezing most likely damaged the entire unit. I would check the water after you make the replacement. Your water may not be as pure as you like.-Chuck> 

RO Question Would it be safe to say that the "waste" water from an RO system is safe enough to use directly on a freshwater aquarium? My RO system has a sediment filter as well as two carbon blocks prior to the actual membrane. I believe that the major issue is with chlorine. Wouldn't the carbon blocks remove this? I understand that the overall hardness of the water will increase, but is it safe for usage without any additives or chemicals?  If further information is necessary, please let me know what I need to provide. < An RO unit is a membrane that allows water molecules through and leaves the rest behind. While the RO unit provides very pure water, the "Waste Water" will contain everything else. I suggest that you check it out for ammonia , nitrites and nitrates. Then check the pH and the hardness. Once all of this is known then we can make recommendations about how to use this water. In agricultural areas the nitrates are already very high in the first aquifer from which many homes get their well water. You really don't want these levels to be very high unless you are planning to start a plant tank.-Chuck> Thanks Andy 

Live Rock and RO vs. RO/DI >Thanks Marina for your previous comments. >>Again, welcome. >Though I must admit I am a little confused regarding curing of the live rock vs. cycling, I thought I was doing both... >>Seek and ye shall find. >What about my 1" sand bed, do I need to vacuum it in small portions as well while doing water changes, I'm afraid I will just suck up all the sand and eventually the crabs and snail I plan on adding? >>At this point I wouldn't really worry about it till it's established.  At that time, yes, small portions as I outlined in the previous response. >Any advice between choosing a RO vs. RO/DI?  How much do I gain in water cleaning power by adding a DI.   >>Alas, I am not the person to ask about this subject.  I can tell you that the deionization along with reverse osmosis is definitely more beneficial, but my understanding is barely rudimentary.  If sufficient explanations are not on our site, then I suggest searching Advanced Aquarist Online, to be found at http://www.reefs.org/ >I was not able to find much regarding RO vs. RO/DI on your site, maybe not looking in the right place.  Thanks again for your input.  Devin >>Quite welcome, maybe this other resource will net you better results.  Sorry I couldn't be more definitive for you.  Marina

- RO Filter Changes, and More - Hi there how are you, I have a couple of questions. <I am well... I will try my best to answer your questions.> how do I know when it is time to replace the filters on a RO unit, I have the Coralife unit with a 1 micron filter, carbon. sediment filter. <There are no hard-set rules, but six months for the micron filter is pretty good - if you change this filter often you can extend the life of the other cartridges. Typically the micron filter is the cheapest in the bunch.> I was told that when the output slows down that you need to replace the filters, my question is do you only replace some of the filters or all of them? <I personally don't wait that long, and my RO unit has clear filter cartridges so it's possible to see when the micron cartridge is getting loaded up with particulates. I've moved a lot in the past year and a half and have found that the mileage on these filters varies greatly.> or is there a better way of knowing when to replace the filters, they are rather expensive so I would like to be sure. <Well, for certain they don't last forever so... you just need to keep an eye on things.> Can you test the water coming out of the RO unit, like if the hardness goes up is this a sign or can you recommend me the best way to know when to replace the filters, also I only use 15 to 20 gallons a week so I shut off the RO unit when not in use, I was told that's its not good for the filter if it is shut off, is this true? <I've not heard this, can't verify it's truth but have shut my filter down many times, in fact right this minute it is doing nothing... think this is in fact pretty standard - as in I don't know anyone who's RO system is running 24/7.> I leave the hoses above the filter so the water does not drain out. <Sounds fine to me.> If I don't need a lot of water why keep it going is this OK to do. <I wouldn't be too worried about it.> I would like to store some of it also. If I used Rubbermaid containers say a couple of 20 gallons how long could I store it for with no air stones or powerheads, or this not a good idea. <It's not good to store water without some form of circulation... it will go stale relatively quickly.> my other question is about the PolyFilter by bio marine, good product, but when do I know when it is time to change it the instructions say you can wash it and reuse it, but I thought I read somewhere on your site that they cant be re-used, also since it is a little expensive how often would you recommend using it. <The Polyfilter is supposed to change colors as it absorbs undesirable chemical compounds. I wouldn't run one of these all the time if cost is an issue - instead just use normal filter pads if all you need is physical filtration. A Polyfilter is both physical and chemical filtration.> my parameters are pretty good, would I still use it even if everything is Ok, or only when I have high ammonia readings, also does the PolyFilter remove trace elements or just the bad stuff, I heard that it wont remove elements out of the salt but will remove any supplements I add to my tank. <It will remove some but not all... but if you're dealing with high ammonia issues, I wouldn't be using a Polyfilter but instead attack the problems at the source.> thanks for your help in advance, your site has been very helpful. Val Toronto, Canada <Cheers, J -- >

- RO/DI Question, Follow-up - Boy, am I confused.  After reading some information in your Q & A part of your website, I am not sure what to do.  You see, I have well water, and I want to get a system.  After reading you website, I see that R/O systems do waste a lot of water. <All the same, this water can be stored and is suitable for drinking - will have both particulates and chlorine taken out before the RO portion of the filter.> What  concerns me is that there are times when we have droughts in the summer. <Would encourage you to invest in a storage container and save the RO bypass water - use for other things.> We have to be careful not to waste water, due to the possibility of our well running dry.  Do you think, in this case, I would probably be better off getting a DI System alone? <With a DI-only system, you will likely spend a fortune in DI cartridges if your water quality is at all off. Would consider having your water tested to see that you need any filtration at all. Many folks have source water that is more than suitable and just add a quality dechlorinator like Prime or Dechlor, let the water mix for a day or so, then add the salt and let that mix for another day, and then use the water.> Debbie <Cheers, J -- >

- More Questions about RO/DI - sorry, I just thought of some more questions. if using an RO/DI, I understand I must first aerate for 24 hours, then buffer correct? <You can buffer immediately, but this should then be allowed to mix for a day or so before adding salts...> do I need to use a dechlorinator then? <No.> second, if I just use an RO, then do I need to aerate for 24 hours, do I typically need to buffer such water, would I need to use a dechlorinator? <No "need" to aerate RO or RO/DI water before adding buffers, but in general is not harmful to aerate constantly during the preparation of your water. If using RO or RO/DI, no need for dechlorinators as the first two cartridges, particulate and carbon will remove the chlorine long before the water reaches the RO membrane.> thanks again guys. Devin <Cheers, J -- >

Top Off Question (5/2/2004) There is a ton of information about buffering top-off on your site, but not specifically what I am looking for.  I just got a RO/DI today, and am trying to figure out the best way to buffer my top-off water.  I use B-ionic, and thought about just using the alkalinity half to buffer (I seem to always have more of the alk part anyways).  Is this a good idea? <Seeing how theoretically the end product of an RO\DI unit should be just pure water, at a pH of 7.0, with no buffer capacity to speak of, the alkalinity buffer is a necessary additive.  However, you will probably also want to add a pH buffer to bring up the pH of the water.  You shouldn't need to add the calcium half if your tank doesn't require the extra calcium, as long as you follow the dosing instructions for the alkalinity half of the B-Ionic>  Should I buy some of that Kent Osmo-prep stuff? <I have had no personal experience with this product, but Kent marine usually makes good quality additives.  However, your current B-Ionic should work fine>  Do I just want to put a little in to get the pH moving in the right direction, or should the top-off water have the same alkalinity as the tank water? <It should preferably have a slightly higher alkalinity, and should most definitely have the same pH.  However, adding an alkalinity supplement will not directly affect your pH; unless it has other buffers as well> If I use b-ionic to buffer alkalinity for my top-off should I add less to my tank on a daily basis? <This totally depends on your system's total alkalinity.  Purchase an alkalinity test kit and monitor results to determine the correct amount of additive needed>  I could just add all my alkalinity solution for the week to my auto-top off container (a powerhead on a float switch in a 4 gal Rubbermaid container). <Once again, be sure to measure your alkalinity and dose accordingly>  I have a 55 gallon and use tropic Marin salt which I believe will mix up fine for water changes without buffering the water first.   Thanks, <No problem> -Ken <M. Maddox>

An Assortment of Issues (5/1/04)   Hi Steve <Hello again.>   I emailed you a little earlier, but I have another question.  This is about my Banggai cardinal fish.  As you know, I have a fish in QT with Popeye.  I am medicating him.  It is hard to tell if my cardinal fish has Popeye or not, since his eyes normally seem to bulge out. <Yes, they have big eyes.>  The odd thing is that he has not been eating well.  He does not seem to be able to find the food when I put it in. I just tried feeding him some live worms by hand, and he ate!  As the uneaten worms fall, he does not follow them.  However, if he feels them touching the sides of his body, he will whisk around and eat them.  This is the first time I have seen him eat.  My question is, does Popeye affect the fish's eyesight? <Not sure.> Can he see? <Worrisome for blindness. I can't remember--did you put any medication in your main tank?> Should I also put him into QT? And with my clownfish. <If he does not act normal soon, you may have to.> I only have one other fish left in my display tank, a Dottyback, who seems to be fine (at least for now). Also, if this is bacterial, I am not sure how they got it.  It must be my water. <Most bacterial infections in aquariums are opportunistic pathogens that strike when something else does the initial damage.>   I have QT all new fish, <good> and have had these in my tank for approximately 8-10 months.  I do have well water.  Who knows what bacteria thrive in it. <I trust you treat it somehow.> I am sure it changes with weather conditions. After reading your website, I also retrieved information about the Kold Ster-il System, by Poly-Bio-Marine. <A very popular and effective unit.> It is a little more expensive, but it is less wasteful, and since I have a well, I thought it might be better, especially when drought season comes along, and we have to be careful with water usage. <Agreed. I should have bought one too, rather than using RO here in drought-stricken Utah.>   PS.  I am also curious, you said that DI water is better, than why is Bob Fenner (I have his book) so high on RO water.   I don't get it.  If DI is better, and waste less, why does anyone prefer RO. <Where water is abundant, RO is cheaper than DI. For many, it is a good choice.> I must be missing something! <Check the copyright. The book is six years old. Many things change. That's why he created WWM. It's very hard to keep a book current. Being in medicine myself, I am acutely aware of this. That's why the web is so wonderful.>

Water Purification (5/2/04) Hi Steve,<Greetings> In answer to some of your questions. No, I am not medicating my display tank, only the QT. <Good> I have had my clownfish in the Qt for 7 days.  I put Epsom salts in and than Maracyn for 5 days.  He is eating, and appears to be healthy, but still has Popeye.  Should I remedicate with Maracyn, or try something different? <If he is eating and acting better, I'd just give it some more "tincture of time" for now.> How long does it usually take for it to go away? <Might take a couple of weeks.> Should I keep him in there indefinitely, unless it goes away. <If it does not go away, you may need to try something else. Take the opportunity to read more about Popeye.> My Banggai cardinal has been eating for the past couple of days, but only from my hand. He seems to see me coming near the tank, when it is time to be fed. He also comes near when I put my hand in the water.  Any ideas of what the problem may be? <Hard to be certain. It sounds like he may be getting better, so it ought to be OK to watch for a few days while making certain your water parameters are optimal.> What types of bacteria or diseases create vision problems? <Toxins and nutritional deficiencies come to mind. Bacterial infection is less likely. Sometimes parasites (including ich) can get on the eye.> You also asked about my well water.  You said "I trust you are treating it".  Well, no I am not. <I just accepted that well water is treated with some sort of chlorine or something. I've never lived in a place without municipal water.> What should I be treating it with? <Maybe that's not needed. I'm probably just paranoid, but I like my drinking water to be free of living micro-organisms. In Milwaukee in 1993, 400,000 people got diarrhea when Cryptosporidium got into the municipal water system. That certainly must have put a burden on the sewer system.> Until I decide on a system, I have been using distilled water. <Now that gets expensive quickly. You also need to buffer it before adding the salt. Search on "distilled water" on WM for info.> I was told it is not the best, but it may be better than my well water. Maybe, I should mix well with distilled.  What do you think I should do in the meantime, until I get The Kold Ster-il system, which I am leaning towards. <Test the well water for nitrates and phosphates. If you live in a rural farming area, these may be quite high from fertilizer. And then there's the pesticide residues... Did you know that there are measurable levels of Ciprofloxacin in several rivers in this country. Some have Prozac and all kinds of other meds too. There's a theory that estrogen-mimicking pesticide residues in drinking water are responsible for the recent increase in the incidence of hypospadias (a birth defect of the penis) in baby boys as well as a recent drop in the age of female puberty. No wonder so many people are filtering their water these days. I guess I'd better shut up before I scare you to death. Anyway, if your well water has nitrates & phosphates, I'd suggest you spring for the Kold-Ster-il ASAP. Can you buy RO water somewhere nearby in the meantime?>

RO/DI Question (4/30/04)  Hi Steve. <Greetings> Thank you for your advice. <Hope it helps.> I did read everything on Popeye. But your information about putting both Epsom salts and Maracyn in at the same time was new. I wasn't sure if that was safe. But I will add the Maracyn tonight. Also, you mentioned a R/O system. I have been considering that. Is it important also to have a R/O-D/I System. What is the difference in these two systems. What does the D/I do? <DI stands for de-ionized. It is an extra stage that removes ions that pass through the reverse osmosis membrane. For the purest water, DI is the most thorough, but for most people RO is sufficient. It removes the most important impurities and is satisfactory for most people. Read more starting here: http://www.wetwebmedia.com/rofaq6.htm >

AP tap water filter hello, I have been using the tap water filter for a while now and have been very impressed. but some say that the water quality isn't that great. what do you think? my water is relatively clean, although its very hard.  < We need to define terms here. Filters remove things from the water. Different filters remove different things and your impressions may depend on what things you are trying to remove from your water. If want to remove chlorine then a carbon filter will work fine for awhile and it will be better for your fish than water that has not been through a carbon filter. If you are keeping hard water fish such as rift lake cichlids then your water sounds perfectly fine and that is all the filtration you will need. If you want to soften your water by removing minerals then you need to go to an R.O., deionization, or distillation to remove these minerals for fishes that require softer more acidic water.-Chuck>  -Jared

Need RO Unit?  Bob Fenner,  <Stephanie>  I have a quandary that I'm hoping you can help with. I cant seem to get a straight answer on whether or not I need to consider an RO Unit for my tap water. I'm keeping mostly Clown Loaches (about ten 4" guys and one 9" - 10" guy) and 1 relatively large (about a foot long) Arowana in a 135 gallon tank. (As an aside, My husband is toying with the idea of starting a discus tank, not that our tap water is conducive to discus at all. But that's not my current problem). The clown loaches I've read can be very sensitive to water quality. So I finally was able to get a hold of a consumer confidence report from my local water company. The measurements I am going to rattle off here are the highest levels found:  PH 9.3 <Yeeikes>  Nitrate 4.23ppm <Yowzah, out of the tap?>  Nitrite .02ppm  Hardness (as CaCo3) 246ppm  Sodium 59ppm  Sulphate 23ppm  TDS 384ppm  Aluminum 1024ppb  Chloride 139ppm  Arsenic 1.2ppb  Barium .13ppm  Copper .09 ppm  Lead 10.7ppb  <Umm, you are indeed a candidate>  I've also attached a copy of the water report, in case I'm not reading this properly. But after looking at those numbers... (if I'm reading it correctly) I'm really feeling like I should be getting my butt out to the local Home Depot and getting an RO unit for my fish. But all the LFS keep telling me its an unnecessary expense for a freshwater tank. Can you please give me your opinion, it would be greatly appreciated!!  <If it were me, my source water I would at least "blend" some treated water (and likely reverse osmosis would be the technology employed)... and mix, circulate the new water a good week before using (in a dedicated plastic trash can...), AND I would utilize the RO water source for my drinking, cooking uses. Bob Fenner, whose wife's family are from northern NJ and have great potable water>  <<NJersey Water Report.pdf>>  Thanks,  Stephanie Koll

- How Do I... RO? - how do I operate my R.O. unit? <Should be fairly simple - water goes in one end, waste water and product water come out the other two.> with the control valve open or shut? <Not at all sure what this valve is or what purpose it serves.> I have the bare bones unit that makes 35 gallons a day thanks for you time. <Would encourage you to get in touch with the folks you bought this from to get any clarification you need directly from them. Cheers, J -- >

Reverse Osmosis or DI?  I have a choice of getting local RO or DI water from a local vender. I fill my own jugs. It is cheap. Only .33 per gallon. They don't offer a RO/DI water only one or the other. The DI water is filtered through carbon before going through the DI unit. At this point I do not have the funds to buy my own unit so filling my own jugs works best for me. My question is, "Of the two choices (RO or DI) is one better than the other for a marine reef tank? I have been using RO but was told DI has less phosphates and silicates in it?  <Hi, I would test both and see. RO doesn't typically have more phosphates/silicates, but can depending on the source. Testing what comes from the LFS is the best way to determine if it's worth the money spent. If both are equal in terms of quality, I would opt for the RO water, as it is free of particles and is likely a more pure finished product. But, with all RO water you must add a buffer. Good luck, Ryan>

The Water Store >Hi, how are you my question is with regards to storing water for water changes. >>Hi I'm fine you can ask away right here I can help you. >I have a 20 gallon tank just for making up my water changes I have a 55  gallon reef tank, I change 10% a week approx: 5 gallons.  So I have enough make up water good for 4 water changes( 4 weeks worth).   >>Ok. >What I didn't realize only until I read on your site is that it is not good to store water for more than one week that it goes bad  or something, is this correct? >>Um, certainly not in my experience!  With proper aeration and cover mixed saltwater can be kept easily for a month.  You would want to bring it up to temperature a day or two ahead of the water change, though it may be easier to just keep a heater in it.  That, and a powerhead or airstone (keep covered well to avoid salt creep, otherwise stick with the powerhead positioned to allow for good surface turbulence). >What I do is fill up my container with 20 gallons of tap water aerate with a airstone a powerhead for 2 days, then I add the salt and aerate for another 2 days with a heater check pH.  Can you advise me is this is the correct procedure? >>Sounds fine to me, although I'm more likely to just mix the water up with a dechlorinator (sodium thiosulfate is quite cheap in large quantities off the web) and keep it that way.  I'd also be more inclined to just use a trash can, lined with black plastic bags, rather than using a perfectly good aquarium. >I am just trying to cut down on the work of making the water weekly.  Sorry for carrying on, also by using this method do I still need to add dechlorinators, or will the chlorines/ chloramines dissipate by aerating for a couple of days? >>Chlorine will dissipate within a day or two easily (if left uncovered), chloramines are another kettle of fish entirely, as the bond with ammonia prevents this dissipation (and is the reason why water municipalities use it!). >Also do you think a lot of other toxins will dissipate with this method, in other words make tap water better? >>No. >Thanks for your help great site I have learned a lot.   Regards, Val - Toronto, Canada. >>You're welcome.  Marina

Permeate pump vs. booster pump 4/1/04 Hi,  wanted to say thanks for helping me ID the problem with my fish last week.  I appreciate the response, as always. <We are always glad to help!> I've been checking your website to see if I could find some info. on ro/di unit "add-on" pumps but couldn't seem to find any posts relating to this question: I'm in the process of trying to purchasing an ro/di unit and I can't decide which of these pumps I should get, either a permeate pump or a booster pump.  I am not happy with the amount of waste water that the  typical ro/di units produce so I want to purchase (one of) the pumps to cut down on the waste water.  I found 2 separate vendors, each of course only selling one of the pumps, so each of them told me I needed their type of pump and not the other.  Can you  offer some guidance as to which pump would be more beneficial as far as helping to reduce waste water, filling tank quickly. Thanks <If you have good water pressure, I would probably choose a permeate pump.  It will increase the amount of "good" water produced by improving the ratio of "good" to waste.  Permeate pumps work on the pressure of your waste water and will not help if you have low water pressure.  If you have low water pressure, I would choose a booster pump.  Booster pumps improve output by simply forcing more water through the membrane.  Unless your water pressure is low, this won't have a huge effect on the ratio of "good" water to wasted water.  Also, booster pumps run on electricity while permeate pumps use water pressure.> Jan oh,  any idea on when Reef Inverts 2 is going to be released?...anxiously  awaiting... <The next book in the Natural Marine Aquarium Series will be "Reef Fishes".  As far as I know, no release date has been announced.  Best Regards.  Adam> Water Softeners Hello!  I love this site (so much information!) but I can't seem to find the answer to my question. Exactly WHY are water softeners (the kind that uses salt exchange) not recommended for freshwater tanks? I have a friend who I have tried to warn against this but she won't accept just "it accumulates chloride ions"....and sometimes I wonder too....(here's the dummy part....we are talking about salt right?) because if you're using the water for water changes, you would be removing as much as you are putting in, right? Not good I'm sure for top offs, but otherwise wouldn't the levels stay the same? And if this is true, then the salt level in your tank couldn't be that high could it? Around the same level as people who use the teaspoon of salt per gallon thing?  Thanks for taking the time to explain this!! Barbara  < Ok here goes. The resin in water softeners uses the sodium (Na+) ions in the salt (NaCl) to exchange with the Calcium ions (Ca++) in the water. So now you water is not as hard but now it has lots of sodium which is not good for fish. To truly soften water you do need to remove the calcium and magnesium ions with a reverse osmosis unit that removes the hard water ions by forcing the water through a membrane that only allows the water molecules through and leaves the others behind. Another method would be deionization. The water runs through a two types of resins that attracts both the positively charged and negatively charged ions leaving essentially neutral water. Distilled water uses evaporation to leave the ions behind while it condenses into pure water. If you just added tap water all the time without doing water changes then the minerals in the water would accumulate and become higher than the water source, unless they were utilized by plants. This is an over simplification but this is how it works.-Chuck>

De-ionization recommendation 3/28/04 Hi all at WetWeb, <cheers> Could you give me information on possible deionization systems that are available commercially and your opinion of them?  I will soon be expanding my coral propagation biz, and I'm looking at the deionization factor rather than going with RO again due to the great amount of waste water generated by RO systems. <agreed very much. "tis what I did for my coral farm> Many thanks, Peggy Nelson.  AquaCorals <my long-standing fave (have bought 3 units in 10 years) is for the Kati Ani brand (the larger models simply go longer between recharges). Seek from Dr Fosters And Smith or Gwynnbrook Farms (MD discus hatchery). Anthony>\

Deionization systems 3/28/04 Hi Anthony, <hey, Peggy> Many thanks for your response on DI systems.  We will soon be moving to a location with more space for expansion of my coral propagation endeavor. It's very exciting.  My good friend, Penny, at AquaCorals in Maine, has had requests for wholesale purchases of tank-raised corals and has forwarded them to me for future response.  I look forward to the possibilities! <outstanding friendship/business... you will both go far in life with such healthy outlooks> Unfortunately, she and I are a long distance apart or would surely be working together! <ah, but the Internet in part bridges that gap amazingly> Thanks again for your response.  You are a good man. Peggy <thank you my friend... wishing you the very best. Anthony>  

Setup Revisited Hello and thank you for the great advice your site is great for information. <You're welcome! Ryan with you again> And of course I have a couple of questions. <No worries> 1. How many stage RO water filter system is good. I figure the higher the better but what would be sufficient? <You can get away with less if your source water is better- and vice versa.  I use a 5 Stage RO unit, and paid less about 150.> And do I need the Osmosis Deionization DI)? Is there a difference between the Reverse Osmosis Drinking Water Systems vs. the regular water systems? The 4 stage drinking water systems are much cheaper then the 4 stage water filter systems. <I believe that the difference is in the actual filters used- I use one that is good for drinking water without any problems.> 2. Is there a difference between using a glass fish tank for my sump vs. a Rubbermaid container? I heard I could use either but are there pros and cons to each or which is better? <Depends on the application used- Glass tanks will need to be drilled for bulkheads, Rubbermaid's can be drilled at home.  Glass is easier to clean, Rubbermaid requires less cleaning.  I would use whichever will allow for more volume.  See ya, Ryan> Thank You, Jason

- Deionization Systems - Hi all at WetWeb, Could you give me information on possible deionization systems that are available commercially and your opinion of them? <Hmm... difficult task. There are simply too many brands and too many becoming available to know them all... for the most part all use the same technology. Doubt there are many true differences between the various units available to the hobbyist.> I will soon be expanding my coral propagation biz, and I'm looking at the deionization factor rather than going with RO again due to the great amount of waste water generated by RO systems. <Would work with a commercial water purification company to design/install this.> Many thanks, Peggy AquaCorals <Cheers, J -- >

R/O Waste (3/25/04)   If I got an R/O unit with a deionizer built in would there be any waste water? <Uh, lots. Depending on the quality of your tapwater, count on losing at least a couple of gallons (perhaps twice that) for each gallon you make.>  My problem is that I live at home and my mom doesn't like to waste water... or pay for the waste. <Can be expensive in places. Could you put the waste to use in a garden?> Any less expensive units worth the money with minimum waste water (gpd is not very important)?  <Not less expensive. Check out Kold-Ster-il at http://www.poly-bio-marine.com/products.htm  Consider posting your dilemma on the chat forum at www.wetwebfotos.com to get input form others.> Thanks...again and again, etc. <Hope this helps. Steve Allen.>

Purifier (RO) question 3/13/04 Hi,  I'm looking to buy a RO/DI water filtration system and found this on  the web.  Do you have any experience with this website?  and would  have an opinion regarding this water purification system?  It seems  like a great deal.  They also sell another water purifier that is  three stages and I was interested in.  I've got a 30 g reef tank and  don't want to go overboard!  But would certainly appreciate any advice.  Thanks, Ben http://www.inreef.com/xcart/customer/product.php?productid=16175&cat=0&page= <I have not done business with this company, but it looks like a great deal!  The thing to be cautious about is the membrane, and DOW are quality membranes.  Best Regards.  Adam.>

Question RO Bob: Can you tell me specifically the compounds USP or salt mixes (not of commercial use, but laboratory grade) I should use to prepare RO water for tropical fish community tank and their amounts per litter? To be more specific which particular electrolytes is RO water lacking of and must be added (brand new tank) in order to keep fish OK? I'll use sodium phosphate buffering system (Na2HPO4 - NaH2PO4). Thank you in advance, Manuel (Mexico) <Manuel, what fishes, that is, which species? Are you using RO because your tapwater is just too solute laden? If so, you might do well to simply "blend" some of it back with your treated, RO water. Bob Fenner> Copper Piping? hello, been browsing your site: simply excellent! <Simply flattered here: Ryan with you today> anyway, I searched WWM for this but could find quiet the answer I am look for. <Gotcha> on one of the many fish forums I post at, there is somewhat of a debate over whether distilled is safe for reefs because many of the units contain copper pipes.  Can you comment? <have heard/read many similar debates.  Sadly, a large amount of variables makes each scenario unique.  I would certainly use a copper test kit on anything that had the opportunity to come in contact with copper.  Any greenish rings on the seams of piping would be evidence of copper.  I don't really believe that you can replace RO water with anything and have similar results.>  or point me to the answer? <yes, actually.  Wilkes University does very precise water testing. http://wilkes.edu/~eqc/homeowner.htm.  If you look around the WWW, you may be able to find this service without charge.  It would take a lab to convince me that it's safe!  But then again, I'm a little paranoid ;)   Good luck, and if you find good articles, evidence, send them our way. Ryan> -Jared - Total Dissolved Solids - Hello Here is a short and sweet question. What should the TDS be in water from an RO-DI unit?? <I'd expect something close to zero.> I have read on advertisements that it will create near zero TDS water. I'm not so sure. <Ok. Cheers, J -- >

How to recharge a deionizer I've looked and looked but haven't found anyone who will lay out step by step how to recharge a deionizer. I know you first have to have one that is rechargeable. any help? thanks Brian <Mmmm, well... some resins are recharged with caustic substances... some with salts... Some can't be economically recharged by simple soaking (require high pressure, temperature in the process). My real advice is to contact the manufacturer or barring this, find out the name of the ion-exchange resins in your unit and search the Net, reference works in a large (college) library re this issue. Bob Fenner>

RO Hey,<Howdy!>      Just gettin ready to fill my 125 reef tank and was wondering, a couple of people are telling me it is a must that I filter my water with a $300 reverse ionization, osmosis filter ,whew! Is this true. I have well water, I am in the mountains of upstate New York, have a small reef set-up now, never filtered before what's the lowdown on this?<I would use a RO unit they filter out many of the undesirable compounds such as phosphate.  I use one and it has helped out a on with algae outbreaks and I have pretty clean water to begin with.  You can also find lots of info on our site: www.wetwebmedia.com.  Cody> Thanks for Your Wisdom, Louie

Chloramines in Question Hi- <Hello! Ryan Bowen with you> Hope you had a nice weekend!! <Rainy days provide the perfect excuse to frag some corals!  Very nice thank you> Do you know if it is necessary to treat deionized water with "Prime" for removing chlorine and chloramine? <Chloramine certainly...Prime works, as do other less pricey products.  Some people skip this step, claiming that a week's storage time allow adequate time for nasties to dissipate...I don't buy it.  Too much invested.> I figure that if I don't need it , why add one more thing into the system. <I share your hesitance. Dechlorinators, and 2 part supplements are generally the only things that ever go in my display tank.>  I also notice that when I buffer the deionized water and aerate for a day or so, and before adding salt, that my mixing tub surfaces get crusted over with some white substance. Any idea what it would be? <Various soluble that have settled.  Good luck! Ryan> Thank you in advance  Dennis

Distilled Water Would an ordinary household type water distiller produce water of a good enough quality to use for top off and salt mix? <Certainly better than tap water.  Be sure to use a dechlorinator, and prepare the water properly.   http://wetwebmedia.com/water4maruse.htm>

Distilled H2O Wow speedy reply! <Well don't jinx it! Ryan here again> OK I'm assuming the dechlorinator would be used prior to distillation, and that the reason would be because the chlorine is volatile enough to distill with the water and still be in the distilled water? <More a back-up step.  I would distill the water, then when done add both salt & conditioner with a powerhead for at least 24 hours.> Rather than use chemicals, would aerating and circulating for 24 hours prior achieve the same result? <Yes, possibly.  But most city water supplies contain lethal amount of chlorine/chloramine to aquatic life...I like to be sure.> Also, you said "certainly better than tap water". Does this mean it is still not as good as RO water? <Yes, RO water would be ideal> Really I am just thinking about saving a few bucks, if I could use water from the distiller, I would not have to keep buying RO filtration stuff. <RO is actually more affordable now than ever.  Compared to other aquarium purchases, it's one of the few I guarantee will benefit just about anyone's tank.  Good luck! Ryan>

KATI/ANI Unit Woes Hello one and all- <Twice in one day! Back again, Ryan> I was looking you some advice from you fine people. I had recently purchased a Kati/Ani unit for my 125gal fowler(170gal total system). System has been running for 2 years. I have 2 MAG 12 pumps for circulating the water. For new water when I was using the deionizer) I add "Prime" chlorine remover, aerate, heat for a few days, then add salt then buffer if needed. I would check ph and alk.  I have had dozens of snails in the tank for about a year and now they have almost all died over the past 2 months. Plus my xenia that had been growing like a weed just fell apart. Now the tank has turned into a huge Cyanobacteria farm. All I can think of that has changed is using the new Kati/Ani unit. The resin in the unit has only changed color about 1/3 of the way after running a hundred or so gallons thru it, so I don't think that the resins  would be a problem.  Plus I have a monitor on the water output. I am thinking maybe my process for treating the deionized water is flawed somehow and a ph or alkalinity swing has killed off the snails and xenia.  Could you share with me how you would suggest preparing and testing it? <I have never used a KATI/ANI unit, but I found a great article about preparing water using one: http://www.pmas.org/pro/ credit due to Mr. Steven Pro, of course.  His steps are detailed, efficient, and his success evident.> I have read before that using "Prime" chlorine remover can make some water tests inaccurate? Would it throw of my ph and alk tests? <Never heard this, perhaps the manufacturer can verify?  Message boards like ReefCentral.com chemistry forum would be your best bet on this type of subject.> I also upgraded from a Berlin turbo skimmer to a Precision Marine Bullet 1. Easily get a cup a week of pretty dark skimmate. <Great> Are there any  tips you might have for using a deionizer? I have switched back to good old tap water for now until I am sure what is going on. Not sure if this is even part of the problem. My guess is that I should stick with the deionized water because now it seems like it is getting worse. <I would change as little as possible...and do lots of small water changes until you get a handle on this.> Also- What color would a poly-filter turn if there were phosphates? When I use one it always turn brown pretty fast. <Poly filter color chart is on the back of the package...sorry bud but I'm at work! (Shh....)> I am poor at putting thoughts into words, sorry if this is e-mail wanders all over the place. <No worries.  You'll get this under control, just keep eliminating possibilities and the result will be the cause.> Thanks for your time.  Dennis

- Kitchen Water Filters - Can you use sink water filters for saltwater changes. Having lots of problems with diatoms in the last 4-5 weeks. My tank has been up since Oct and never had a problem till now. I have been using the tap water from the first. Now I'm getting this algae. I have a Brita filter on the sink and thought it would take the chem.s out. <Would certainly take out the chlor-ines/amines... would mean you'd need to change the filter cartridge more often.> I do water changes every other week but been doing them more often since this is going on. I use the conditioner to take out the chlorine and such and use instant ocean. I've read about the other filters to use but so expensive. I thought about the Brita on the faucet. <Will take out some stuff, but not all... not diatoms.> Please let me know thank you. <Cheers, J -- >

- RO + DI - I am switching to a reef tank.  I am using a R.O. system to purify the water that is going into the tank.  After I bought the R.O. I started reading that "simple" R.O. was really not good enough, but that water should be put through a D.I. (mixed bed).  I had a Marine Pharmaceuticals water filter (which is a mixed bed DI), so I hung that on the product from the D.I. So how do I know this is giving me the best water? TDS is an indicator, but how much is OK and how much is too much.  Conductivity is another way of measuring water.  Again, what is OK and what is not? <What I think is not OK is over-hype of various aspects of this hobby... water filtration would be one of those areas. Do think the folks who benefit most from RO/DI are the companies that make the filters. Your RO filter will be fine, even the waste water from RO is cleaner than tap water. In other words, any filtration is a positive step forward, and at a certain point you start to strip useful stuff out of the water, requiring supplementation to make it worth using with artificial salts. I'm sure your combining of these two filters is better than just the RO and certainly better than nothing. Would not be concerned with TDS.> Thank You George <Cheers, J -- >

RO/DI  water -high Ph reading Hello, I was wondering if you have ever heard of a ph reading of 9.00 on the  "clean" water coming from a 4 stage Kent Hi-S RO/Di filter? <depends on the source water.. do test your tap water to see if its very alkaline><<?. RMF>> I am using a digital PH monitor which I have checked the calibration twice using 10 & 7  solutions to ensure accurate readings and it does not seem right that this  water should have such a high PH. <agreed> I am confident the PH controller is accurate based on the fact the ph monitor read exact in the calibration solutions. FYI-(My tap water out of the sink measure 7.6ph) & my salt mix (Red Sea Salt) using this 9.0ph Ro/Di water mixes after aeration is 8.4ph. Is this RO/Di reading of 9.00ph normal? <may be a moot point with the salt mixing at a nice 8.4> I am using the same ph monitor to check each. Any idea? Thanks for all your help. I love your guys web site. Miles <it will be interesting to see if it lowers in time (something in the unit imparting alkalinity. Anthony>

Re: RO/DI  water -high Ph reading Hi again! <howdy... Anthony Calfo in your service> I finally figured out my issue. I retested my water after flushing the new membrane again. Here is the catch. I started isolating lines from my membrane one and narrowed it down to my final stage. The membrane and DI cartridge works like a charm. The 6th stage of my unit is a GAC filter and the dust from it was spiking my pH. <perhaps from the phosphoric acid that some GAC is washed with (also imparts phosphate for algae growth... beware). Be sure to by phosphate free carbon> So all the RODI water I had on hand I spilled out as it was not so pure after all. I figured this after I did a 10% water change in my tank. However, after removing the GAC (post filter) cartridge, the final stage is the DI cartridge return water. I could not ask for more perfect water. Why they put a "polishing filter" at the end beats me. How can you polish what is "perfect"? <several possibilities... not the least of which is to buffer pH (unrelated to the phosphoric issue above), the unstable purified water is often naturally acidic and needs to be aerated and/or buffered> I did need a little break in, but that final stage IMO is just not worth it. In short, you were correct about the break in period, its just that the final filter was essentially contaminating otherwise perfect RODI water. Thank You, <the real problem is that the quality of carbon used in this unit was bunk. A high quality grade or exchange resin media instead (like Poly-filter by Poly Bio-marine) would be even better. Best regards, Anthony>

RO without DI I recently purchased an RO unit without the DI module.  Is it worth buying this module? <Yes, likely removing most dissolved solids (as well as liquids and gasses) with reverse osmosis will get you initial water that you're looking for> Is it worth buying a TDS monitor? Thank you <Yes, if you are curious, want to know some measure of the purity of your produced water. Bob Fenner, who uses R.O. but doesn't have a TDS measure.>

Treating RO/DI water? 2/13/04 Anthony--I lose a quart a day, that I need to top off. Should I use buffered top off water, or just straight rodi water for a couple of days, since I added to much of SeaChem's buffer already.   Thanks Charlie <its fairly risky my friend. Its a better habit/solution to dilute a chemical imbalance with a water change (as other manipulations of chemistry may have occurred) and then resume with properly aerated and buffered seawater or fresh water for top off. Under almost no circumstance should you use raw, unaerated and/or unbuffered RO/DI/Distilled water for SW aquariums. Too unstable. Anthony>

- Trace Minerals in Bottled Water - I have reviewed all the FAQs and articles on your website regarding reverse osmosis and deionized water. I did find one mention of Culligan as a possible solution for RODI water that can be purchased from a manufacturer. <There are a good number of companies that will deliver bottled water.> I have a 12 gallon reef so don't need water in huge quantities so purchasing it would be a cost effective solution (especially since they deliver to your door). Here is my question: After the RODI process they add minerals back in for flavor and I am not sure if they are harmful to a saltwater reef. <Probably not.> This is a quote from their label: " nutritionally insignificant amounts of sodium bicarbonate, magnesium chloride, calcium chloride and sodium sulfate" Are these chemicals harmful? <Likely not in the amounts in which they are present.> I have not done any testing because I wanted to see if it was even worth it. Based on your response, I will either test for parameters or forget it. <I'd go full-speed ahead.> Thanks!  Brigitte <Cheers, J -- >

- Homemade Tapwater Purifier -  Hello, I'm very new to marine fish keeping hobby and I am planning to install a marine tank of 60 gallon in my house. Since RO unit is very expensive in Malaysia, I plan to just by a prefilter + sediment filter + 2 carbon filter (skip the RO membrane which is 5 time more expensive than every of the filters I plan to buy) for tap water filtration purpose only. Do you think this is sufficient and safe? <I think it will make a difference as opposed to doing nothing.> Or do I need to add other treatment like anti-chlorine, etc? <Best to test the water coming out of your filtration unit and make a determination from there. Hard to predict the results without knowing anything about the source water.>  Thank you very much !  <Cheers, J -- > 

- Homemade Tapwater Purifier, Follow-up - Thank you very much for your professional advices and speedy response. Really appreciate it. FYI, I plan to setup an aquarium system of having DSB/plenum in both main tank(60 gallon with overflow, sitting on top level of the stand) & sump tank (20 gallon sitting on bottom level of the stand), which will be a FOWLR system. I plan to install 1 inch height of undergravel filter base plates (from my old tank) with a screen as the plenum, and then top up another 3 inches of medium graded sea sand (about 0.5 to 2 mm grain size). Is there anything wrong in my plan? <Don't think so.> I plan to buy 20 fishes of average 2 inches size, will I over stocking my tank (with the plan of changing 10% water once every two months only)? <I don't like the sound of that at all... overstocking and then changing the water only every two months... seems like a path to disaster. Much better to under-stock, perhaps five fish and regular water changes, like 10% every two weeks.> Having 2 DSB/plenum is better or just 1 at sump tank will do? <Every little bit helps, but I don't think you have enough in place to handle your overstocking/seldom-water-changing plan.> My sump tank will act as refugium as well (will add live rock + sea plant), may I know how much lighting I need (I plan to buy one 30W full spectrum operates for 18 hours)? <Should be plenty of light.> And any suggestion on the optimal height of water level in sump/refugium (I plan for 6 inches height from sand bed)? <This will vary depending on the plumbing of the system - transit volume... what the sump will handle when the power is turned off. There is no ideal height, only what works.> Also, I learned that having a wet/dry filter in a tank with DSB/plenum will be creating excessive nitrates problem. <Well, the two will be working against each other.> Is this true or can you further elaborate/comment on it? <Please read here: http://www.wetwebmedia.com/nitratesmar.htm > I plan to setup a dry/wet filter in the overflow (large square tower), to utilize the empty space. Is it OK? <I would skip the wet/dry filter.> Sorry to bothering you with so many questions but I really appreciate to hear your professional advise before I start (in fact I have already bought the tanks but haven't go into plumbing yet) Once again, thank you very much. I really learned a lots from your articles + FAQ. <Keep reading.> Best rgds, PJ <Cheers, J -- >

- Homemade Tapwater Purifier, More Follow-up - Thanks for your patient and valuable info. <My pleasure.> I have a question (which bother me for so long), if let say we can consistently maintain the nitrates below 1ppm by using a very efficient filtration/denitrification method, e.g. DSB/plenum + refugium for FOWLR tank (consider with MODERATE stocking only) + regular control on trace elements/calcium/dKH/magnesium. <I have my doubts as to just how low your nitrates will be... don't think your plenum and DSB will be large enough.> Do we still need a frequent water change? <Always.> Or can we just do a monthly or bi-monthly 10% water change? <10% every two weeks is fine.> The reason I ask this question is U.S. sea salt & R.O. water is quite expensive in Malaysia (consider frequent changes) and tedious, <My friend, you've signed up for a tedious hobby - if tedium bothers you, perhaps you and the fish would be better off if you collected stamps.> and also, I have a friend who have actually experienced this (his FOWLR tank has been running for 2 years without any problem, with nitrates maintain at almost 0ppm) < - > Forgive me if I have a poor understanding on below answer from you regarding the wet/dry, <Well, the two will be working against each other.> does it mean that they will be opposing each other? <Yes.> Or they work between each other? <No.> Can you elaborate further? <A wet/dry filter can produce nitrates in abundance and likely in larger quantities than your DSB/plenum will be able to accommodate.> Knowing that a complete nitrogen cycle need aerobic and anaerobic bacteria, which dry/wet will do a good job in aerobic portion, and the plenum&refugium will serve the anaerobic portion, why do you suggest I skip the wet/dry? <Rather than use the wet/dry, you'd be better off with more live rock in a standard sump. Please read the article I sent you in my last response, much information for you there.> Thanks & have a nice day !  Best regards, PJ

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