• Back to the Basics: The Art of The Water Change

    With advances in technology, collection practices, and communication among hobbyists, it’s never been easier to enjoy a healthy and beautiful display of reef creatures in your own home. After spending some time in the hobby and achieving success, you might still see someone else’s amazing reef system, supporting a thriving population of rare or challenging species and wonder to yourself, “How did that guy do it?” Did he/she spend a lot of money on fancy gadgets, or just hit a run of extraordinary luck?

    You didn’t think it would be that simple, did you? Let’s be honest. Successful reef systems involve the merging of proper planning, good design, and husbandry techniques to create optimum conditions for captive animals to thrive. To sum it up, in a word, it’s about acquiring habits- the good habits that set apart a truly successful hobbyist from the masses. Sometimes, it’s helpful to re-visit seemingly basic practices to move ahead successfully.

    One of the easiest (and best) things that we can do to achieve and maintain success with our captive reef systems is to perform regular water changes. Yet, it is baffling to me why so many aquarists resist performing regular water changes on their systems. In fact, you’re bound to encounter hobbyists who will proudly boast that they perform a water change “once in a while”, if ever!. Seriously?

    Water changes tend to be viewed by most hobbyists as a necessary evil; a practice that we begrudgingly embrace to achieve a modicum of success with our aquariums. I mean- it must be easier to dose something or to tweak our controller.. anything but the siphon hose!

    However, the benefits of regular, frequent water changes are quickly apparent, and the cost of not doing them is equally motivating (nuisance algae growth, poor livestock health and long term water quality issues). If you put it into perspective, you’ll soon realize that performing regular water changes on your system will pay great dividends in better health for your aquarium!

    Today’s reef aquariums often contain substantially larger amounts of biomass than in decades past. Efficient filtration systems, protein skimming, “miracle” additives and chemical filtration media have arguably enabled today’s reef hobbyist to keep more animals in a given system than ever before. Of course, this is not always a good thing! These technological “crutches” can foster a false sense of comfort and lead to relaxed husbandry efforts by the hobbyist.

    Many of us hobbyists, both new and experienced, seem to be easily charmed by manufacturer’s claims that you’ll be able to get by with fewer, or even no water changes in your aquarium by using their “magic elixir” or hardware. In reality, heavy bioloads necessitate more aggressive husbandry practices to process dissolved organics. The old environmental adage that “The solution to pollution is dilution” is more important than ever before.

    How much to change depends on a number of factors. You can take into account the various methods that you a re using to assist with nutrient export in your system already. Aggressive protein skimming, use of chemical filtration media (such as activated carbon), and vegetable or animal filtration (macroalgae or filter feeders in refugia) can alleviate some of the burden on water quality, reducing some of the need for massive frequent water changes. However, it’s not possible to avoid these water changes altogether. Like death, taxes, and morning breath, it’s unavoidable, kids!

    Think about it. Even with a 50% monthly water change, 50% of the nutrient-laden water is still left behind in your aquarium. And the nasty stuff will continue to accumulate month after month. Am I advocating 50% monthly water changes for everyone? Of course not- it’s simply not practical for everyone. However, it is completely realistic to perform a weekly 5%-10% water change (that is- 5% to 10% of your aquarium’s water volume), or even 2%-5% twice a week! The object here is to get into the habit of making frequent small water changes, so that these organics don’t have the chance to accumulate to any great extend in the first place. When performed on a regular, frequent basis, water changes help provide the inhabitants of your closed system with a stable, consistent environment. And stability is a big key to success in the hobby!

    Do you need more convincing? If you’re regularly dosing your system with “additives”, think of all of the money you’ll save by regularly exchanging some of your water with freshly-made synthetic seawater. Any decent brand of synthetic salt mix will deliver a high quality dose of the perfect balance of trace elements and compounds required to keep your animals in healthy condition. In a nutshell, freshly-made seawater replaced during water changes is THE best “additive” that you can use!

    It’s no secret that lighting issues are some of the most hotly-contested topics in the hobby. It’s bitterly ironic to see hobbyists spend small fortunes (or large ones!) on sophisticated lighting systems, only to ignore the fact that poor water clarity is working against them and their photosynthetic invertebrates. To make matters worse, the discoloration need not be great to create a significant reduction of light in the water, Light penetration is greatly aided by regularly exchanging water. Don’t take my word for it, though; take the time to notice the difference in color between new synthetic seawater versus aged water from the aquarium when compared side-by-side in clean white plastic buckets.

    I wonder which water is the new water?


    “How much do I really have to change- and how often?”

    Less than you might think, but more often than you’d assume! A weekly 10% water change is a manageable, easily-accomplished practice that will yield consistent water quality and provide a healthy, stable environment for your animals.

    Better still would be two 5% water changes a week. Before you get ready to pelt me with calcium reactor media for recommending such a practice, think about it for a few seconds: Five percent of your aquarium’s water volume is really not that much. We’re only talking about 5 gallons in a 100 gallon aquarium, or just 2.5 gallons in a 50 gallon aquarium, performed on say, Wednesday and Sunday. By following such a routine, your aquarium’s inhabitants are never more than 3 days away from the next water exchange. Interesting concept, isn’t it?

    Water changes, regardless of how frequently they are performed, need not be complicated procedures. You can perform a meaningful and efficient water change in just a few minutes with decidedly low-tech methods. By “low-tech”, we’re talking about a flexible plastic hose, a bucket of appropriate size, and a few towels for those inevitable “accidents” that always seem to happen when water, carpet, and a watchful spouse are in the equation!

    Obviously, when performing a water change, you’ll need to utilize high quality source water and a reputable synthetic salt mix. As with all incoming water, the water that you will be utilizing needs to be aerated and warmed to the appropriate temperature at least one day in advance. Utilizing untreated tap water is a bad practice, and I am shocked to find that some hobbyists still use untreated tap water for their systems. Unless you have an excellent quality of source water (like a well), you’re much better off using some form of water pre-treatment (like reverse osmosis or deionization).

    Also, it should go without saying that the specific gravity of the new water should be adjusted to match that of the aquarium water. It should, but I can’t tell you the number of times I’ve worked with hobbyists who suffer “anomalous” livestock losses after water changes, and a quick test of the new water indicated parameters which varied wildly from those in the system .

    Always use an accurate hydrometer or refractometer to measure the specific gravity of your prepared saltwater before use. Never underestimate the caustic nature of newly-mixed synthetic seawater. Chemical reactions in dissolving synthetic salt mixes can take some time to complete. Ideally, you’ll prepare your seawater several hours or days in advance of use in your aquarium.

    While you’re making those more frequent water changes, you will become more intimately involved with your aquarium. You’ll see what is really going on in your system, and be able to take corrective measures promptly if required. It also cannot hurt to clean or replace mechanical or chemical filtration media during these changes, which will further assist in maintaining good water quality.

    In relatively little time, you’ll begin to notice some wonderful effects on your system. Fishes will display brighter colors, feed better, and be more alert and active than ever before. Corals and invertebrates will display significant improvement in color, growth and recovery following imposed propagation techniques. Nuisance algae will begin to subside, and your aquarium will take on a visual clarity that will astound you. Follow the simple practice of regular water exchanges and you will be well on the way to your own gorgeous reef aquarium that will make fellow hobbyists wonder how you did it!

    'Til next time…

    Stay Wet

    Scott Fellman
    www.facebook.com/scott.fellman
    Comments 19 Comments
    1. melev's Avatar
      melev -
      Thanks for the write up, Scott. Now you've got me thinking about doing more water changes.
    1. agsansoo's Avatar
      agsansoo -
      Great article. I do a 10% wc weekly, from day one (3 years). Not so sure about trying the two 5% water changes a week ... Saturdays are my tank maintenance day. This isn't too bad for us with small tanks, larger tank owners might be lucky to do two wc per month.
    1. washingtond's Avatar
      washingtond -
      Thanks for the write up Scott. We have always performed a 20%/ month water change since we started both our aquariums and have always had great coral growth and very few problems with algae. I really do not understand people that like to brag about not performing water changes when all the benefits are well known.Water changes and keeping all the parameters in the aquarium to correct levels is so important to our overall success.
    1. goingsalt's Avatar
      goingsalt -
      great write up..
    1. Scott Fellman's Avatar
      Scott Fellman -
      Thanks for the kind words, and good points by all. I think the main point that I'm trying to convey is that, when it comes to water changes, anything is better than nothing! Consistency is so important, IMHO. Yes, regular water changes do involve some expense, time, and energy, but I think that they are such a beneficial and important part of reef husbandry that it''s almost a shame not to perform them. I hate getting to preachy, but I am so surprised at the volume of inquiries I see from people with problems that rarely, if ever, perform water changes on their systems. It seems like so many potential environmental issues can be prevented, or at least mitigated somewhat, by regular water changes...I'm glad (as are the salt manufacturers!) that more and more hobbyists have gone back to the basics and are "working the fundamentals" of the hobby.
    1. Turbosek's Avatar
      Turbosek -
      I advocate making a system of checkoff lists that are followed on a daily, weekly, monthly, etc schedule. When you follow checkoff lists, you just "do it". When we leave husbandry to "if I feel like it", we are less likely to stay on the system. Remove the emotion and feeling from your husbandry tasks and you will be more regular in maintenance.

      I have to live by this principle in my work as well. I am self-employed and no one is there to kick my butt into working. I have to kick my own butt. By having systems and checkoff lists I follow, it removes the emotions and I just do it.

      It is ok to have technology to make our hobby easier to systemitize and less time consuming, but never to eliminate or reduce the frequency of tasks designed to prevent a tank crash. You never hear of a pilot trying to make his preflight check list shorter. Technology has made it faster for him to get through the list, ie. he does not have to physically check the oil pressure, but the items never gets removed from the list.

      Most of us thrive on following a plan, developing systems, and monitoring results, so successful hobbyists never mind the issues of micro-managing our tanks:-)
    1. Mojo~'s Avatar
      Mojo~ -
      Nice write up, its funny though. I just started doing this the last couple weeks i have been doing 5 gallons every 3 days. ITs pretty easy now that I set up a salt water mixing barrel in the garage. Siphon a bucket pour a bucket back in. Things are improving already. I used to be one of those that would do about 10 gallons a month. Now its about 10 gallons a week. Now I just need to land on a good salt. using brightwell now. Will try of bag of Tropic marine Pro that I have sitting there next.

      Thanks for the write up.
    1. stangchris's Avatar
      stangchris -
      gotta agree, when i started slacking on water changes and doing them once a month my system was ok, but now that im back to 5 gallons a week its been a whole new system sps that was brown got color and rest just took off in growth. this is one thing all of us do as we get comfortable with our systems. Thanks Marc for this great article im going to link this in some local forums.
    1. TomNeely's Avatar
      TomNeely -
      Thanks Scott!
    1. BigAl07's Avatar
      BigAl07 -
      Excellent write-up!

      I'm a HUGE fan of Water Changes and actually just linked to this page from over at Reef Sanctuary where a newbie asked, "How often and how much do I need to do with regards to water changes." PERFECT timing!!

      I feel that being on a set schedule really helps me to stay on top of my game. Sometimes "life" throws a curve ball here and there but for the most part my wife and most of my friends know that on Sunday evening I'm preparing new Salt Water and on Monday evening I'm doing a 20% - 30% water change. I can tell you first hand there is a MARKED improvement in my systems in regards to water changes. I have a tank here in my office that gets neglected and it has more "issues" than my other tank probably 20 to 1. Just because it's not At Home it doesn't get weekly (lets be honest MONTHLY doesn't even happen) water changes.

      I like to use this motto often:

      The Solution to Pollution is DILUTION!

      Here is a good quote I actually use in my signature on the other site
      " Originally Posted by angerhater
      ...dont chase numbers...find them, in a bucket of new water
      "

      I was reading recently (magazine or online... I can't find the article right now) that small and frequent water changes lead to a much more stable tank long-term rather than larger less frequent water changes. Apparently it takes much longer for a tank to reach it's point of "Equilibrium" with large water changes and this point of "Equilibrium" is where true health and growth stem from. For this reason I'm seriously considering incorporating a "Continuous" water change system in my next set-up. We'll see if that really happens after I BUILD the house.

      Again GREAT write-up Scott. Very well written and informative!!
    1. Sheldon's Avatar
      Sheldon -
      Easily one of the simplist maintenence routines one can perform to maintain a healthy reef. Whenever things start to get off in my own tank, the common denominator is always inadequate water changes. I always marvel at how people with pristine reef tanks say they rarely do water changes. I can't seem to be able to keep line looking good without biweekly 20% changes.
    1. Jynxgirl's Avatar
      Jynxgirl -
      Even if your only going to do a small water change, its better then not doing them and trying to dose and make up for it. And its just cheaper to do water changes. Great article.
    1. Konadog's Avatar
      Konadog -
      Scott, this comment " pelt me with calcium reactor media " had me laughing way to hard, thanks. Next time I see you, there's some reactor media coming your way
    1. reefnfun's Avatar
      reefnfun -
      awesome article, I need to do water changes more often. My system is plumbed intothe sewer so it is as easy as turning a couple of valves. I am going to get started on 1 right now. Thanks for this info
    1. T5FL's Avatar
      T5FL -
      Im now going to go to once a week water changes, i use ocean water as i live in florida and our local fish shops sell it and is readily available, what is your opinion on ocean water vs synthetic as far as what is more beneficial or does it not matter?
    1. melev's Avatar
      melev -
      You might want to check the news and see where the oil is in relation to your collection spot.
    1. T5FL's Avatar
      T5FL -
      Quote Originally Posted by melev View Post
      You might want to check the news and see where the oil is in relation to your collection spot.
      Definitely, if it gets that close, no one including the fish shops will use it, Im over in Palm Beach County, right now were fine.
    1. saxerphoner's Avatar
      saxerphoner -
      I know this is an old article but I guess I'll see if anyone is listening :-)What does everyone think about hitting rocks with a turkey baster or power head to get the detritus out before a water change or stirring the sand bed some? Should their be a focus on the sump or refugium? Do you leave the powerhead running during your water change?
    1. melev's Avatar
      melev -
      If you blast the rocks off with a small powerhead or turkeybaster, that's a perfect time to do a water change. I never bother the sandbed intentionally. I prefer to pump water out of the sump rather than out of the display, and then I refill the sump -- the return pump is off while I'm doing this.