This debate will last through eternity! But it's 2020 and have things changed?

[Paul B]

You have said yourself - that you cant keep certain acorapora- right?

MN that used to be the case before I upgraded my lights from the water cooled ones I built to real lights that are bright enough. I now have quite a few acropora, maybe 5 or 6 that have grown from fingernail size to 6 or 7" since I moved here two years ago.
I also use 100% NSW now because I live near the sea.

 

[MnFish1]

MN that used to be the case before I upgraded my lights from the water cooled ones I built to real lights that are bright enough. I now have quite a few acropora, maybe 5 or 6 that have grown from fingernail size to 6 or 7" since I moved here two years ago.
I also use 100% NSW now because I live near the sea.

Nice - I assume also your nitrates are below 100? (btw I meant that seriously - nice corals)

 

[Paul B]

LOL, yes my nitrates are below 100 which is I assume another reason I had problems with acropora.
I think they are around 12 or so due to my algae scrubber.
I have other SPS and they all grow nicely.

 

[CavalierReef]

The question, to me, is "are routine water changes beneficial to YOUR tank?" In my 32 Biocube, YES they are.

 

[Taylor t]

Water changes are really good, IF, your tank is going through a rough time, or a cycle, not all cycles are destructive. I’ve changed (twice) (2) 10 gallon water changes the past year on 185 gallons of water (125 DT with 40 sump and (3) 20 gal tanks dark), to suck out crap, in the past year. I’ve found, a stable system that is supplemented, doesn’t need frequent water changes, but I don’t have sps anymore. I supplement and rarely change water, but there are good reasons for frequent water changes on some tanks, just not my current tank at this time.

 

[The Night Driving Avenger]

I'm a complete noob but i think for me water changes are beneficial, i use NSW so ill be getting free copepods etc in it

 

[Joe Rice]

I'm curious to learn about the practices of those who have been successful running a tank without doing routine water changes. Rather than hijack this thread I've started a new one here:

Questions for folks who aren't doing water changes

In a recent poll here on R2R, about 12% of folks said that they no longer do routine water changes. Personally I tried and wasn't successful. So I'm curious to learn about the practices of those who have been able to make it work. How long has your tank been running without water changes? Do...

www.reef2reef.com

 

[Paul B]

I'm a complete noob but i think for me water changes are beneficial, i use NSW so ill be getting free copepods etc in it

If you use NSW as I do, you can change water every hour if you like and it won't harm anything.
But that is because natural sea water is sea water and not fake sea water which I feel is not that good to change to much.

 

[The Night Driving Avenger]

If you use NSW as I do, you can change water every hour if you like and it won't harm anything.
But that is because natural sea water is sea water and not fake sea water which I feel is not that good to change to much.

interesting, how frequently do you do water changes and how big is your tank?

 

[SebastianReefer]

I have 6 tanks so I do a 20 to 30% water change once a month

 

[SebastianReefer]

I have 6 tanks so I do a 20 to 30% water change once a month

Depending on how my corals look my most mature tank 75 gallons gets a 25% once a month but the last few months I have not noticed any change in corals they looked great before and the same after wc

 

[Paul B]

interesting, how frequently do you do water changes and how big is your tank?

My tank is 125 gallons and I change about 20% of the water 4 or 5 times a year. Even when I used mostly ASW for over 40 years I had the same schedule.

 

[EMeyer]

Theres been quite a few posts in this thread making a distinction between artificial seawater and natural seawater. While I think its a useful distinction to bring up, I want to make two points about this distinction. (I'll say up front I am very pro-water change and very pro-natural seawater)

1. Assuming one uses an artificial salt mix with natural seawater parameters (and not one of these crazy 10dkh mixes), where is the evidence of a difference between NSW and ASW? I get that theoretically there may be differences in the levels of unmeasured compounds and compounds present below the levels of detection.

But where is the evidence of this? And more importantly, where is the evidence that any of these unmeasured/unmeasurable compounds have any affect on the animals in our tanks?

I'm not saying I disagree in principle, it just seems like a statement that needs support.

2. The entire distinction (ASW vs NSW) only matters for one proposed benefit of water changes (maintaining levels of minor components).

The other proposed benefit (removal of substances that accumulate over time) is not affected at all by the hypothetical differences between ASW and NSW. Doesnt matter. Removal is removal.

My own gut feeling is that the benefits of water changes have more to do with removal of some things (e.g. refractory DOC) than maintenance of trace minerals etc.

 

[Paul B]

But where is the evidence of this? And more importantly, where is the evidence that any of these unmeasured/unmeasurable compounds have any affect on the animals in our tanks?

There is no direct evidence which is why I said I "feel" ASW is not as good. Chemically speaking ASW is woefully lacking in many trace elements of NSW and they can't be added. NSW has every element on Earth in it and no one knows if those things are needed or not. Algae, corals, volcanoes, meteorites, and run off all contribute to whats in NSW.
Also I feel that a new tank set up with ASW will not be very healthy at all compared to NSW and I have set up a lot of tanks.
NSW needs no time to age as it is already billions of years old.

Just my opinion of course and as I said, no direct evidence.

Artificial seawater
From Wikipedia, the free encyclopedia



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Artificial seawater (abbreviated ASW) is a mixture of dissolved mineral salts (and sometimes vitamins) that simulates seawater. Artificial seawater is primarily used in marine biology and in marine and reef aquaria, and allows the easy preparation of media appropriate for marine organisms (including algae, bacteria, plants and animals). From a scientific perspective, artificial seawater has the advantage of reproducibility over natural seawater since it is a standardized formula. Synthetic seawater is also known as artificial seawater and substitute ocean water.

Gravimetric salts

Salt	Molecular weight	g kg−1 solution
Sodium chloride (NaCl)	58.44	23.926
Sodium sulfate (Na2SO4)	142.04	4.008
Potassium chloride (KCl)	74.56	0.677
Sodium bicarbonate (NaHCO3)	84.00	0.196
Potassium bromide (KBr)	119.01	0.098
Boric acid (H3BO3)	61.83	0.026
Sodium fluoride (NaF)	41.99	0.003

Volumetric salts

Salt	Molecular weight	mol kg−1 solution
Magnesium chloride (MgCl2.6H2O)	203.33	0.05327
Calcium chloride (CaCl2.2H2O)	147.03	0.01033
Strontium chloride (SrCl2.6H2O)	266.64	0.00009

NSW
Quote:
The processes that deliver dissolved, particulate, and gaseous materials to the oceans ensure that they contain, at some concentration, very nearly every element that is found in Earth’s crust and atmosphere. The principal components of the atmosphere, nitrogen (78.08 percent), oxygen (20.95 percent), argon (0.93 percent), and carbon dioxide (0.038 percent), occur in seawater in variable proportions, depending on their solubilities and oceanic chemical reactions.
End Quote:

The "main" chemicals in Natural Seawater are added to ASW but almost none of the trace elements can be added because they change composition with temperature depth and how they mix with other ions. Much of these things are not known if they are needed or not, but our creatures evolved in them.

The rest of the article is here about NSW and whats in it:

Seawater - Salinity, Minerals, Oceans

Seawater - Salinity, Minerals, Oceans: The principal components of seawater are listed in the table. In contrast to the behaviour of most oceanic substances, the concentrations of the principal inorganic constituents of the oceans are remarkably constant. Calculations indicate that, for the...

www.britannica.com

 

[EMeyer]

Much of these things are not known if they are needed or not, but our creatures evolved in them.

Just wanted to add that philosophically I am completely on board with this statement - after millions of years of evolution in natural seawater chemistry, it seems likely that natural seawater chemistry is ideal.

 

[MnFish1]

Theres been quite a few posts in this thread making a distinction between artificial seawater and natural seawater. While I think its a useful distinction to bring up, I want to make two points about this distinction. (I'll say up front I am very pro-water change and very pro-natural seawater)

1. Assuming one uses an artificial salt mix with natural seawater parameters (and not one of these crazy 10dkh mixes), where is the evidence of a difference between NSW and ASW? I get that theoretically there may be differences in the levels of unmeasured compounds and compounds present below the levels of detection.

But where is the evidence of this? And more importantly, where is the evidence that any of these unmeasured/unmeasurable compounds have any affect on the animals in our tanks?

I'm not saying I disagree in principle, it just seems like a statement that needs support.

2. The entire distinction (ASW vs NSW) only matters for one proposed benefit of water changes (maintaining levels of minor components).

The other proposed benefit (removal of substances that accumulate over time) is not affected at all by the hypothetical differences between ASW and NSW. Doesnt matter. Removal is removal.

My own gut feeling is that the benefits of water changes have more to do with removal of some things (e.g. refractory DOC) than maintenance of trace minerals etc.

I agree. I also feel that many of the missing 'trace elements' - are added when we feed the fish. This is a little 'off topic' - but - lets face it - most reefers don't live in an area where its prudent or possible to change there water with NSW - yet are quite successful. I think this alone is basically a retrospective experiment suggesting there is not much difference?