why do water changes?

[Ben Henwood]

I personally feel that you need to have a pretty well established tank and good equipment to run a no W/C tank. You are trading one chore for another. You are not making water and changing it, instead you are dosing the elements the tank needs and maintain a nutrient export method (fuge or algae scrubber). A no W/C tank is 100% possible, but its not for everyone.

You need to know what you are doing and you need to be setup for it. Over-sized skimmer, Cal/Alk dosing (like a CaRX), trace elements (like Red Sea Reef Program)...etc...etc...etc.

I think if you are confident in your reefing abilities to monitor and respond to issues, go for a no W/C tank. It is your tank after all. LOL. BTW...water changes are sometimes necessary even when you have a no W/C setup. Like someone else said, its a tool. It doesn't have to be "the way".

 

[Shigshwa]

In a system where nutrients are removed and major and trace elements are dosed back, I think water changes are only necessary to correct elements that have become too high in concentration. That's what I do, running Aquaforest with a few additional elements mixed into the dosing solutions (determined by ICP). When ICP shows an excess of an element, or if the balance is too far off for all of them, I do a big water change to set them in place.

It makes me wonder what the more cost effective solution is, throwing out old water for new seawater, or dosing elements only to throw them out for RODI? I think that with chemical dosing, I end up saving space, since I don't need to keep a vat of seawater or RODI on hand.

Water changes serve different purposes for different methods. It reduces nutrients and refreshes water chemistry for traditional methods, and serves to refresh water chemistry and reduce accumulated contaminants for those who have other means of removing nutrients or dosing back elements.

 

[zoso]

As a newbie to this great hobby I find this thread to be of great interest when I relate it to a previous hobby I was infatuated with. For several years I captively breed various species of poison dart and mantella frogs.
I built vivariums to house the frogs and many were built as micro ecosystems with waterfalls , streams and ponds. By building multi layers of specific substrates I was able to create a vary efficient water filtration. By having springtails and very high humidity all waste materials decomposed perfectly. Also maintaining a balanced level of frogs the vivariums were not overloaded and there was seldom an excess of dead feeder insects that could have caused rot and problems . Trust me there were many trial and errors , but that was what made it so interesting and helped me learn and grow with it .
I only added water by means of two heavy misting per day. I seldumly had to do a complete water change , even when I would create a dry season to help stimulate them into breeding the water beneath the substrate would be arrated (not circulated ) but not changed , sometimes water added after a few months of drought.I never introduced anything that was not quarantined for the appropriate time frame, and NEVER any wild caught invertebrates, frogs or plant life. I realize this may not be the appropriate comparison as we are dealing totally aquatic and not a terrestrial/aquatic combo. But I believe that with the same diligent and attentive care the same could be achieved with our hobby.

Great thread Matthew :)

 

[ZoWhat]

Yes, I agree everyone should spend $50/month in dosing/additives versus a $25/month water change

I'm in....:rolleyes:



.

 

[WWIII]

The salt mixes we have available to us have done most of the work for us. They provide salt with elements in balance near natural sea water or balanced to ranges we know are acceptable to keep a reef tank. If you go no water changes it is recommended to test for all of these elements and to keep them in balance based off of those tests. If you overdose some of these elements then a waterchange would be a viable option to lower that particular element back to "normal" range.

Waterchanges are a pretty easy way to keep our tanks balanced fairly similar to natural sea water when it comes to trace elements and even the major elements, depending on waterchange schedule and tank consumption. Waterchanges also remove nutrients that accumulate within the tank.

Today it is now possible to do limited to no waterchanges, but it is advised to get icp testing done to make sure our tanks are staying close to the suggested ranges of natural seawater or other ranges known to lead to successful reefkeeping. Many who do no waterchanges dose elements, both macro and trace, based off of these tests. They also utilize methods to reduce nutrients in many cases. There are many different ways to get the same thing accomplished. In the end what most are trying to accomplish is keep a healthy tank stable and close to the suggested ranges we have come to know work well for a reef tank. The means to the end can differ, and even change, as one becomes more in tune with their own tank and experiences.

 

[Matthew Morrison]

I can’t thank everyone enough for every post on this matter.

 

[SteadyC]

I really only do them to clean something, like vacuum the sand, or clean the overflow, or other things. I have done them also, to reduce aluminum levels. As far as using water changes to maintain chemistry, the only solid answer is, it depends on your tank. Nobody can tell you, for your tank that water changes is enough of an option for maintaining minor and trace elements. As JDA said, major elements (the top 3 for sure, calcium, alk, and magnesium) are almost always needed to be dosed on top of water changes.

After that, let’s say your tank consumes 10% potassium, well a 5% addition through weekly water change is obviously not going to cut it. Every week, you are losing 5% that the water change is not keeping up with, and thus you should dose. For some people, water changes is enough to maintain these elements, maybe they have less demanding corals, maybe they do larger volume water changes, maybe they do more frequent or automated water changes, maybe their salt has higher amounts of these elements, maybe they don’t actually know and are just assuming water changes is enough without actually testing. Whatever the case might be, only your tank will tell you what it needs.

It is no where near good enough for someone to tell you, just do water changes for minor and trace elements supplementation and don’t do additives. BTW, not all additives cost a lot, and also if your tank doesn’t need a lot of these elements. For example, I dose 5ml of iodine a week, a 250 ml bottle will last 50 weeks, at $7 per bottle, because it’s late, let’s just call that .60 cents a month. I can’t get anywhere near the above quote of $50 a month of additives, for everything. And I do between 5 or 10 gallon water changes a week, and it’s not enough for my tank for a few elements like potassium, iron, iodine, manganese.

On the flip side for nitrate and phosphate, the amount of water change it takes to make an impact on these numbers is usually very substantial. Let’s say your nitrate is 50 ppm. When you do a 10% water change, you still have 45 ppm nitrate after the water change, very little change. If you did a 50% water change, your nitrate is still 25 ppm. So, they really aren’t effective as a nutrient export solution on their own, so you have to supplement by using algae, protein skimmers, GFO, organic carbon, corals that are nice and big so they are consuming these elements, etc. Water changes never reduced phosphate alone for me, so I still had to run GFO for a while, and now I’ve moved to macroalgae.

Carbon does absorb some things, but not everything. This is the second area where water changes can help, as a tool in the toolbox. Let’s say your tin, or aluminum like for me, become elevated for whatever reason, a water change is the only way to restore elements like these back to proper levels. However, this requires that ICP tests are used, to give you the data that action needs to be taken.

If I narrowed a list, water changes are a good thing for staying connected to your tank, cleaning and working on the things you should, and reducing the elements that no other method can reduce. After that, maybe, only maybe, are water changes able to supplement minor and trace elements adequately. You would have to ascertain what your tank needs. For my tank, water changes alone are nowhere near enough.

 

[Mortie31]

All in all...... Many nutrients are absorbed and lost due to evaporation. Dosing helps restore essentials but the minor elements are also of value which are replenished during course of a water change

What trace elements are lost due to evaporation?

 

[Mortie31]

I believe if you design your system or modify it to become non water change and are testing regularly and adding back in needed elements both major and minor then I think this is good strategy we have lots of successful non water change tanks in Europe, however if you just can’t be bothered to do water changes and seeing it as an easy thing to skimp on, and you don’t do and the testing and adding then I think you will end up in trouble at some point.. I firmly believe in regular water changes having tried both methods...

 

[Bob Escher]

I do water changes for two reasons
1, it allows me the time to take a real good look at my tank. To check it all out while thecwater level is lower than normal. To see things with no water movement that I might not see otherwise.
2. Peace of mind that I know that I’m removing some contaniments. Maybe not all of them, but some
and there are probably more reason but mainly peace of mind

 

[Lasse]

All arguments about WC as an excellent tool are based on having a perfect salt with perfect blend of trace substances available. I doubt that this always is true. I do not do WC on routine - I will only do it if I need to.

Sincerely Lasse

 

[jda]

All arguments about WC as an excellent tool are based on having a perfect salt with perfect blend of trace substances available. I doubt that this always is true. I do not do WC on routine - I will only do it if I need to.

Sincerely Lasse

While true, over 25 years, I have seen more tanks have issues with old tank water than with freshly mixed Instant Ocean or TM Pro Reef. While no salt is likely perfect, you do not need perfection to be better.

When people see tanks that are "no water change" it is important to note how the did the bulk of the thriving that they are doing, as well as what has happened since they quit. Most tanks were quite well established and had a good amount of good-will established (low phosphate concentration in the aragonite, good population of anoxic bacteria and a great keeper). Any tank like this can do quite well for a while once you stop water changes. A few years later, you see people start to lose coral that they could otherwise keep while some do great. Most choose to just live with the deaths to accommodate their methodology. Some, however, see the folly in their thinking, start to change water again and once again be able to keep all of the coral. It all depends on what they expect and are willing to live with - you will not find too many long-time NWC people who have had great success keeping the harder stuff. If you want to go down this route, follow the thread of somebody who is doing it for 5+ years - do what they do and when you look at their threads and tanks do not just look at what is in them, but also what is not.

JB is doing a no-water change thing. He has not been doing it for long, but I consider him to be one of the best out there. In a handful of more years, I am interested to see how he is doing with it.

Also, keep in mind that Dr. Holmes Farley is right... no tank is truly no water changes... skimmate, salt creep, etc. all will do this for you if only even in small amounts.

 

[WVNed]

I personally feel that you need to have a pretty well established tank and good equipment to run a no W/C tank. You are trading one chore for another.....
Like someone else said, its a tool. It doesn't have to be "the way".

I also feel I am using a method I am comfortable and safe with. I can and do screw things up often.

I admire the people that run a static no water change system but I don't think I will ever be one.

 

[vetteguy53081]

What trace elements are lost due to evaporation?

Not trace,,,,Minor elements such as iodine, potassium, strontium, molybdenum, and aminos as examples.

 

[Sallstrom]

While true, over 25 years, I have seen more tanks have issues with old tank water than with freshly mixed Instant Ocean or TM Pro Reef. While no salt is likely perfect, you do not need perfection to be better.

When people see tanks that are "no water change" it is important to note how the did the bulk of the thriving that they are doing, as well as what has happened since they quit. Most tanks were quite well established and had a good amount of good-will established (low phosphate concentration in the aragonite, good population of anoxic bacteria and a great keeper). Any tank like this can do quite well for a while once you stop water changes. A few years later, you see people start to lose coral that they could otherwise keep while some do great. Most choose to just live with the deaths to accommodate their methodology. Some, however, see the folly in their thinking, start to change water again and once again be able to keep all of the coral. It all depends on what they expect and are willing to live with - you will not find too many long-time NWC people who have had great success keeping the harder stuff. If you want to go down this route, follow the thread of somebody who is doing it for 5+ years - do what they do and when you look at their threads and tanks do not just look at what is in them, but also what is not.

JB is doing a no-water change thing. He has not been doing it for long, but I consider him to be one of the best out there. In a handful of more years, I am interested to see how he is doing with it.

Also, keep in mind that Dr. Holmes Farley is right... no tank is truly no water changes... skimmate, salt creep, etc. all will do this for you if only even in small amounts.

Just out of curiosity, what is the harder stuff that you say hardly can be found in any long term NWC tank?

 

[Matthew Morrison]

I really only do them to clean something, like vacuum the sand, or clean the overflow, or other things. I have done them also, to reduce aluminum levels. As far as using water changes to maintain chemistry, the only solid answer is, it depends on your tank. Nobody can tell you, for your tank that water changes is enough of an option for maintaining minor and trace elements. As JDA said, major elements (the top 3 for sure, calcium, alk, and magnesium) are almost always needed to be dosed on top of water changes.

After that, let’s say your tank consumes 10% potassium, well a 5% addition through weekly water change is obviously not going to cut it. Every week, you are losing 5% that the water change is not keeping up with, and thus you should dose. For some people, water changes is enough to maintain these elements, maybe they have less demanding corals, maybe they do larger volume water changes, maybe they do more frequent or automated water changes, maybe their salt has higher amounts of these elements, maybe they don’t actually know and are just assuming water changes is enough without actually testing. Whatever the case might be, only your tank will tell you what it needs.

It is no where near good enough for someone to tell you, just do water changes for minor and trace elements supplementation and don’t do additives. BTW, not all additives cost a lot, and also if your tank doesn’t need a lot of these elements. For example, I dose 5ml of iodine a week, a 250 ml bottle will last 50 weeks, at $7 per bottle, because it’s late, let’s just call that .60 cents a month. I can’t get anywhere near the above quote of $50 a month of additives, for everything. And I do between 5 or 10 gallon water changes a week, and it’s not enough for my tank for a few elements like potassium, iron, iodine, manganese.

On the flip side for nitrate and phosphate, the amount of water change it takes to make an impact on these numbers is usually very substantial. Let’s say your nitrate is 50 ppm. When you do a 10% water change, you still have 45 ppm nitrate after the water change, very little change. If you did a 50% water change, your nitrate is still 25 ppm. So, they really aren’t effective as a nutrient export solution on their own, so you have to supplement by using algae, protein skimmers, GFO, organic carbon, corals that are nice and big so they are consuming these elements, etc. Water changes never reduced phosphate alone for me, so I still had to run GFO for a while, and now I’ve moved to macroalgae.

Carbon does absorb some things, but not everything. This is the second area where water changes can help, as a tool in the toolbox. Let’s say your tin, or aluminum like for me, become elevated for whatever reason, a water change is the only way to restore elements like these back to proper levels. However, this requires that ICP tests are used, to give you the data that action needs to be taken.

If I narrowed a list, water changes are a good thing for staying connected to your tank, cleaning and working on the things you should, and reducing the elements that no other method can reduce. After that, maybe, only maybe, are water changes able to supplement minor and trace elements adequately. You would have to ascertain what your tank needs. For my tank, water changes alone are nowhere near enough.

That was a great response to the question

 

[silvernblackr35]

Water changes definitely aren't necessary with the proper setup, but they can do everything at once you mentioned that takes different specialized equipmentand media to do. I find water changes to be cheaper and easier than fiddling around with different media's and reactors especially if you are running a smaller tank. The larger you go the less water changes really have an impact unless you are doing 50% a month or more.

 

[Randy Holmes-Farley]

Not trace,,,,Minor elements such as iodine, potassium, strontium, molybdenum, and aminos as examples.

Iodine maybe. Perhaps as organoiodine compounds. The other three listed inorganics are not ever going to be lost due to true evaporation from a reef tank. I also do not think there will be any evaporation of amino acids, except perhaps if they get into unusual and uncharged forms.

 

[Ento-Reefer]

I think my tanks have always looked better when I change water. I like to siphon the sand at least once per month and honestly it really isn't that much work. I don't haul buckets. Set them up to be automatic if you are lazy. I am currently doing 15 % twice a month and according to my ICP test, the only element that was low was iodine.

 

[Dburr1014]

If fuge and gfo remove phosphorus. If carbon removes what carbon removes. If skimmer removes all the gunk and particals. If calcium, magnesium, alk, major, and minor trace elements are added. If cycled tank removes all ammonia nitrite and nitrate. Then why should i do water changes?
this is not an argument. This is a legit question. Im willing to do water changes. I just don't understand why i am doing them.

I Close my house up in the fall to prepare for winter. In the spring I like to open the windows to get some fresh air in the house.

Kinda the same thing if you were to never leave your house. I wouldn't want to live in stale air all the time.