Are water changes REALLY necessary?

[Randy Holmes-Farley Verified Community Expert]

This is also what makes me wonder about the benefit of water changes in supplying or removing trace elements. It seems that some salt mixes have unexpectedly high amounts of some elements (I've seen tin, lithium, aluminum), while some are low, and that this varies from batch to batch, never mind manufacturer to manufacturer. So while you might think you'd be 'leveling out' trace elements by doing a water change, you might actually be removing too many or supplying a toxic excess. Plus, when measuring at such small concentrations, any amount of contamination could have a big effect on results...

It sure would be nice to have a pipe running in from the ocean...

Yes, understanding what is in your salt mix can be helpful in understanding what it is adding and what it is not.

 

[scoobysnack77]

I think there's something to be said for stability, and against the routine change of large percentages of water. And changing smaller amounts means that you lose the benefits of dilution (removing some organics, toxins, accumulated trace elements). The only solution to this imo is to implement a continuous water change system that swaps out a large percentage of water without affecting stability.

well so far i swap about 20 gallons a week on my 120 gallon tank. that seems to keep my nitrates at 0 and my phosphates at .02 which is good. after my water change both are at zero. so i think im doing a good thing by changing water. id like to get my nitrates up to .50 to 1ppm but no matter what i do i can't get nitrate to show up. i tried going 3 weeks without a water change and the only thing that rose was my phosphates

 

[scoobysnack77]

If your doing that many chemicals then I think you'll be ok. I stopped doing water changes due to too clean of water but will start back on it soon. It's all in preference, I would still recommend water changes from time to time to refresh everything.

agreed thanx

 

[scoobysnack77]

I wouldn't attribute any special knowledge to Red Sea of an area that is quite complex and poorly understood.

FWIW, there no way that a single recipe can be the correct dosage of 31 different elements to 10,000 different aquaria with totally different needs.

One only needs to look to the wide range of trace element data that folks are getting with Triton testing to see that what is needed and what is building up varies considerably from tank to tank.

that makes sense but it seems alot of people are using the red sea's coral color program for example bulk reef supply just added a video on youtube about adding the red sea coral colors program to thier BRS 2 part system. they also believe its pretty well balanced and it supports the needs of "most" sps and lps . but your right in a sense because different corals have different needs. i have used the coral colors with the red sea 2part and my experience has been GREAT. corals are growing like crazy and thier colors are insane. but i dont think thats entirely the 2part. i also use thier coral food reef energy a&b which is an amino act,fatty acid and vitamin supplement. i know people get results with other products as well but i didnt get these results with the b-ionic 2 part that i used for over a year.

 

[Sangheili]

If you haven't seen an SPS tank without water changes that is impressive you aren't looking hard enough. Check any DSR or Triton tanks (like GlennF or Triton's own display) for example.

No water changes is very doable and IMO much better but it cannot be done blindly. You need to understand what elements your tank is consuming and supplement them, as well as efficiently remove organics and unwanted things (such as the aforementioned coral warfare).

It requires much more testing, capital, and learning, but it can result in a much more stable microcosm of the ocean.

 

[Randy Holmes-Farley Verified Community Expert]

No water changes is very doable and IMO much better but it cannot be done blindly.

Why better?

 

[Sangheili]

Why better?

These are not always true but generally (and assuming using a dosing system):

1) Less introduction of unwanted elements.
2) Less changes in temp, salinity, calcium, alk, pH, etc.
3) Less risk of a bad salt batch.
etc.

TL;DR - Less changes = more stability.

 

[Randy Holmes-Farley Verified Community Expert]

If they are done slowly with a good salt, I don't think those are important.

For example, I change about 1% daily spread over many 15 minute periods each day, so "2" is not any issue.

I do not find that the IO that I use is bringing in any substantial amount of unwanted elements that I can detect. I am not concerned about slightly raised lithium or bromine, and stopping the changes won't necessarily bring them down.

In 19 years, I never had any issue I'd attribute to a bad batch.

But water changes do bring in things I want and exports some I do not wat, so I think they are desirable in my system.

 

[beaslbob]

IMHO what is important is to have a balanced stable ecosystem.
which is easy for nitrates phosphates but harder for calcium/alk/mag.
but still the goal.
water changes at levels convenient to hobbists will reduce but not eliminate builds up and depletions of anything.
just my .02

 

[scoobysnack77]

If you haven't seen an SPS tank without water changes that is impressive you aren't looking hard enough. Check any DSR or Triton tanks (like GlennF or Triton's own display) for example.

No water changes is very doable and IMO much better but it cannot be done blindly. You need to understand what elements your tank is consuming and supplement them, as well as efficiently remove organics and unwanted things (such as the aforementioned coral warfare).

It requires much more testing, capital, and learning, but it can result in a much more stable microcosm of the ocean.

yea I think I'll stick to water changes I definetly don't have the experience under my belt to toy around. My tank looks good and everything is growing so I'll play it safe

 

[tonymission]

I do 150 water changes per day

 

[ps2cho]

Replenish trace elements, and stop the build up of toxins. Both from corals and your house. You aren't necessarily doing it for nutrient control...more toxic nutrient prevention and replenishment for stuff you cant, and shouldnt realistically need to test for.

 

[gregoryleonard]

I do 150 water changes per day

Tony, are you using Tropic Marin Pro now for that?

 

[tonymission]

Tony, are you using Tropic Marin Pro now for that?

Bio actif... Seeing great effects but might change to the standard TM since it's the same alk. My experience with pro reef has been like 6dkh. Getting 8.2 with TMBA and carbon source seems to be helping my export efforts.

 

[riche]

But water changes do bring in things I want and exports some I do not wat, so I think they are desirable in my system.

I have found that you seem to very knowledgeable when it comes to this stuff.

How often or how long do you suggest between w/c's? Just a ruff ball park idea

 

[Randy Holmes-Farley Verified Community Expert]

Thanks.

I generally suggest the equivalent of about 1% daily, however you choose to do it. I also think more smaller changes is better than fewer bigger ones.

 

[riche]

Thanks.

I generally suggest the equivalent of about 1% daily, however you choose to do it. I also think more smaller changes is better than fewer bigger ones.

Thanks for teh quick responce


I just plumbed my 120 dt with the sump and frag tankand fuge all plumbed to where I just switch a valve and it drains into the floor drain

I also have my ro tank plumbed to the ato tank when ever it gets low I just turn on a pump and open a vlave and now I think I will do something with pre-mixed water

 

[Larry L]

I think water changes are useful because they provide long-term stability for any bad stuff that might accumulate, and any good stuff that might get depleted - even the stuff you can't test for and supplement.

We have all seen water change graphs like Randy's (Water Changes in Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com) or water change calculators like TheH's (http://www.hamzasreef.com/Contents/Calculators/EffectOfWaterChanges.php) but I think something that does not get emphasized enough is that over a period of time, those graphs flatten out and approach a constant value.

Suppose you have some "bad" stuff that accumulates in your tank at a rate of "x" per month (e.g. copper or some other contaminant from food, whatever). If you use the calculators or do the math, it turns out that if you do 10% monthly water changes, the amount of that stuff in your tank will never go over 9x. Change 25% per month and it never goes over 3x, change 50% per month and it never goes above 1x.

Or, suppose you have some "good" stuff in your tank that depletes at 1% per month (trace elements, who knows). Assuming your replacement water has the ideal levels of that stuff, then doing 10% water changes per month means that over time the amount of that stuff will never go below 91% of ideal. Changing 25% per month would keep it at 97% of ideal, and changing 50% per month would keep it at 99% of ideal.

So even though the water changes might not keep things at exact optimal levels, it will keep them at stable levels, even for the stuff you can't test for or supplement or otherwise remove.

 

[mcbridepcm]

This debate has been around sense the early 70's, the stand question. The defining answer usually was do your water changes. A old analogy I used to hear was this. Your locked up in a room, where you have to breath use the bathroom, and excersise. You have no window to open so you can get fresh air. Your trapped. The water change for your entire livestock could be thought as opening that window and getting a nice breath of fresh air! Scientific NO but not everything is easy to explain in this hobby. Until recently the mechanisms to maintain sea water within the parameters we can measure has alluded aquarium keepers for decades. Water changes might be difficult, and or costly or what ever the reason, but morally, and ethically they make sense for the inhabitants we are in charge of. Some one in the hobby has always tried to figure how to get away not doing water changes, the ocean is constantly exchanging its water through natural processes, lakes streams, rivers and the atmosphere....etc. how can our glass boxes compete?