Are water changes really necessary?

[joeman]

Here is a question I have been asking for a while and have not got a definitive answer for:
Do you think it is feasible to create a system where water changes are not required?
Assume a very low bio load, plenty of live rock sitting on a sand bed and a sump + refugium + skimmer + denitrator + UV sterlizer...
One long standing reason for changing water has been to dilute (reduce) the nitrates that accumulate from anyting that was not caught by the skimmer then overwhelmed the anaerobic bacteria in the live rock etc...
Well with the addition of a dinatrator it becomes possible to maintain nitrates at zero.
I also believe it is possible to maintain a similar level of control over phostphates etc.
So the next reason I have heard is that "we just don't know what is important in water = additives alone are not sufficient", but this argument just does not stand, for I use RO/DI water (essentially just H2O) and add synthetic salt mix - what is the difference between that & topping up with RO/DI water + additives to maintain target levels?
So the real question is: what would be missing or what would accumulate to such levels in the tank that it would harm anything trying to live in the tank?
It would be great to get people's thoughts on this as I just can't get to a satisfactory answer myself.

 

[SSalty]

I don't know the definate answer but, what would the reasoning be for having a low Bio-Load and spend lots of money on equipment just so you wouldn't have to do a water change?

Perhaps you are not looking to achieve this, rather you are just looking for a justification?

 

[joeman]

Hi SSalty,
Good comment/question.. you are right, I'm not looking to avoid anything, more to understand things better.
I get as much (if not more) pleasure out of this hobby keeping a naturally well balanced system rather than having a massive showcase that pushes everything to the limit. I tend to buy most of my tanks inhabitents based upon function rather than appearence (though this is not always the case :-).
I'm not going to start talking about the planet and how it is a closed system, because I don't intend to start precipitating the water that evaporates from my tank :umbrella: or anything like that - I just find it all very interesting.
so - still looking forward to further thoughts on this one...
j

 

[jermpool]

I used to not do water changes a few years back and I was constantly fighting hair algae. With my newest tank I do regular water changes and only have an occasional patch of hair that my snails get before the next day.

My new theory is this: Not changing water in your fish tank is like not changing water in your bath tub. After a few baths with the same water you just arent getting the same results. Even though you are adding soap and shampoo.

Just the way I have started looking at it recently.

 

[Bifferwine]

About the additives... It is not just the RO water that contains trace elements. Most (if not all) salt brands contain a balance of trace elements and minerals that you need. So if you do not do water changes, these trace elements will be used up by your animals. The only way to replenish them is by using an additive or doing a water change with salt that contains them.

 

[reeffreak]

I can account to the zero nitrate,so why do water change debate.Seven months and still no nitrates on two test kit.My xenias,sand bed/fauna(anerobic bacteria),and low bioload and perhaps the little algae I have must be using it up before its detectable.I still do 5 gallon water change on my 75g. just to replenish trace elements.BTW,this is on a system with no refugium.For me its easier to do small weekly water changes than to constantly dose for elements that are or are not being use.I say if it works for you then why not.

 

[yote]

They way I look at it. If a salesman at auto-zone told you that you could run such and such oil additive that you would never have to change the oil in your vehicle again.Would you trust him.
I personally dont know what needs to be added back to the water,But I know that waste products need to be removed.
A water change is like an oil change for your car.If you dont bite the bullet and do it,,you'll eventually wish you had of. Just MHO.

 

[RigoSharon]

yep..water changes is a must..weekly the better

 

[Rcpilot]

Why not do your own research?

Set up a nice 55g reef and let us know how long you can keep the animals alive without changing the water?

I'm all for experimentation and challeging the norm. I rarely take what people tell me for the "gospel" truth. But, sometimes the reason for an accepted practice is because bad things happened when those accepted practices weren't followed.

But, since you can't get a diffinitive answer, perhaps the simple answer is-- nobody knows, because nobody has tried it.

Try it. Report your findings to the rest of the reef community. :Cheers:

 

[fishbait]

i can see where you are coming from. i have pondered the same question to myself at one time. i also have a light bioload, 0 nitrates, and 0 phosphates, algae blooms are the biggest reason i stay on top of my water changes. also there are trace elements that are used up by corals that we cannot dose for.

 

[SSalty]

Oh yeah, and welcome to Living Reefs:sfish::bounce::mrgreen::^::Cheers:

 

[joeman]

Thanks everyone for your thoughts and input. I think I will try the experiment. Assuming I will only keep a few small fish, a basic 'clean-up' crew, maybe a couple of polyps (not delicate corals to start with at least), I could use 'Balance Blocks' or something similar to maintain trace elements, but what elements would you suggest I add / monitor closely, and which parameters would you say are key to determine success? (pH, Alkalinity, Calcium, Nitrate & Phosphate - I suppose I should keep an eye on Amonia and Nitrate for this test as well)....
Actually, just in general, what would we regard as success? No dead animals? No Algae? Perfect water parameters?...
I won't be able to start the experiment for a couple of months, so time to plan anything I need to, but will post pictures and parameters as I go along once I get started, in case any of you are interested...
Thanks again, j.

 

[joeman]

Hmm - I thought I had replied to this, but it seems to have vanished...

I think I will try the experiment with a basic setup including a few small fish, a 'clean up' crew, maybe some soft corals and would like your input to determine:
i) What key aditives should I use (I could use "Balance Blocks" to ensure a supply of a wide range of elements, but what else would be needed)?
ii) What parameters should I measure? (In addition to pH, Alkalinity, Nitrate, Phosphate, Calcium - Nitrite & Ammonia)
iii) What would we regard as success? No dead animals? no Algae? Perfect parameters?
I won't be able to get started for a couple of months, but when I do I'll keep pictures and parameters posted regularly for anyone who is interested...
thanks again,
j

 

[joeman]

ahh - there it is - well now you have the same question asked two different ways :-)

 

[yote]

Test for ammonia,nitrite,nitrate,phosphate,PH alkilinty,calcium,iodine,magnesium,manganese,potassium,strontium,&molybdenum

 

[reeffreak]

Besides what you already mention maybe Iodine and magnesium.There are others but I'm uncertain of there importance.Regarding whats considered success.Healthy and thriving system,very little nuisance algae and near perfect parameters(nitrate 20pppm and lower).

good luck with the experiment.

 

[Doc]

I for one like to keep things alive. I would rather do what seems to work for me and that keeps my system healthy (although I have been known to push the limits for my angelfish and corals) rather than see how far I can push and risk killing hundreds of dollars of fish and corals - call me a whimp. I will leave the science experiment to those of you who are far smarter than I. I will crack open a cold Pepsi and watch my angelfish swim around my corals. Cheers :Cheers:!

-Dr Marco :sfish: