Natural sea water for tank ?

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hi guys...

does the use of natural seawater for your tank have any pros or cons?
is it safe for use?
would the salinity be stable / if not then would synthetic salt need to be added in there?
when water evaporates can R/O water be added to it?

thanx guyz
 
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also which would be better, natural or synthetic sea salt? reason is if we use natural biological filteration like the DSB,LIVE ROCK,CHAETO ect then why not use natural seawater, also if sea water is used will it be clear in the tank?
 

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Hi Ocellaris - I have only ever used natural sea water in my tank. I know that Mekaeel uses MOSTLY NSW, and only sometimes uses synthetic salt/RO water mix.
So does Sean Koekemoer.

So - it depends on where you are located (inland or not) and whether you don't mind the "natural impurities" of NSW.....

Some folks don't want this, and believes the water MUST be 100% clear of any impurities.

I think it is a personal choice. NSW or synthetic salt/RO mix. And also perhaps a cost-based decision - which would work out cheaper for you.

The pro's of NSW - it is NSW after all - that's what the corals and fish live in in any case in their natural habitats. BUT - it could differ in water parameters, from time to time - depending on rain-fall, how hot it was for a few weeks on end, currents, algae blooms, plankton blooms, pathogens (bacteria strains), POC's (Particulate Organic Matter), DOC's, chemical analysis..... all these things could differ and affect the NSW.

Not that it is a problem as such, but it is just something to be aware of.

With synthetic salt and RO mix, you do not get that - the salt mix is mostly more the same every time.

With BOTH NSW and synthetic salt/RO mix, you have to top your tank off with RO water, as fresh water evaporates, increasing the salinity of the water.....
 
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ok so have you ever had any of these blooms ect that has caused havoc for you? how clear is the NSW is it some what cloudy?
 

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No Occelaris - I don't have problems with any blooms in my tank (either cyano nor diatoms). My water is QUITE clear - but there is some POC's in the water which I can see floating in my water currents in the tank.
BUT, these POC's feed my corals - so I don't mind them at all.
 
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hi jacquesb would you recomend me using NSW, im going to start of a FOWLR setup, so will these poc's be captured by my skimmer since i wont have coral, when is it advisable to collect NSW and at what depth?
 
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hi vzyla by saying you used NSW once does this mean you have changed over?
guyz then collection of NSW, would the salinity change, what i mean is if it is too high would we have to dillute it with R/O water or if its too low would we have to add like a synthetic salt mix and also can you do a 10% water change uing synthetic salt mix while having NSW present in your tank
 
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Actually i am staying inland and collected NSW from Sudwana while on vacation there, as a test run starting up my NANO. Normally i mix.
 

jacquesb

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Ocellaris - I get my NSW from the 2 Oceans Public Aquarium. The guys who fetch their own water usually get their water from a deserted beach - away from rivers or estuaries, and not close to any harbour or public beach either. The water should be the "cleanest" there. They usually use a pump to pump the water from +-2 metres below the surface (as far as I know).

The salinity issue w.r.t the source water is not that much of an issue at all - because you measure the total salinity of your tank. And - you ONLY usually replace 10-15% of your tank water volume at a time. You then adjust the salinity of the tank water, if need be, by using RO water......

Yes - the skimmer should remove many (perhaps not all) of the POC's in the NSW.

And YES - you CAN do a water change with synthetic salt mix while having NSW in your display tank without problems.
 

jacquesb

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The salinity in the sea is very constant, and would not need to be altered.
Abgg - this is not completely true. The salinity and temp, as well as ORP, including pH (and some other parameters) of NSW can and do differ/fluctuate during the course of the year. It depends on many external influences what these parameters of the sea water would be.
The influences include (but is not limited to):
- amount of rainfall during or preceding the period of collection
- whether there are fresh water rivers running into the sea in a 10km radius around where the NSW is collected
- whether there was extreme warm / hot weather on the days preceding the time of NSW collection
- current changes in the sea (the salinity of sea water differs depending on water depth) - sometimes current upwellings bring more nutrients from the depths of the sea, which influences salinity and other water parameters
- the season also determines the salinity, water temp, pH, amount of POC's, etc in the water
etc.
etc...
 
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i would like to use NSW but so undecided
where in durban can i get more cleaner NSW from
the umhlanga and lalucia beaches are closer to me,
i guess if i can get a good spot where i can collect good cleaner NSW from then i will go the NSW way
 
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could someone please do a small calculation on what one would spend on 10% water change on let say a 500l tank?I know that you will save a lot of money especially at the initial stage when you fill it up.thanks
 
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jacquesb said:
Abgg - this is not completely true. The salinity and temp, as well as ORP, including pH (and some other parameters) of NSW can and do differ/fluctuate during the course of the year.
OK, sure. But we can always calibrate so that "pretty constant" is true, can't we. ;)

But as long as you don't gather too close to a river mouth, how big can the fluctuations be? And it's mostly gradual. I read an article that took measurements close to where 2 rivers entered the ocean, and it was talking about salinity ranging between 35.3 and 29 over a year for the place with the largest range difference. If you're not close to a river, that should be much less, and given you change 25% or so of the tank water, the effect is even less - anyone has any idea how this compares to the fluctuations caused by evaporation and top-up?

I just wanted him to feel comfortable that NSW can be used if it's from a clean source. I mean, lots of people use NSW as is. The fluctuations aren't material if you gather from the correct place, are they? I haven't used NSW myself, just thought from what I read that you don't really need to worry about salinity given you gather at this or that place where pollution isn't a problem.
 
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