Natural Sea Water.. low calcium?

[stan]

I buy purified NSW from the LFS. It's real sea water with all the trace elements, proper salinity etc etc etc. that they sell for $1 a gallon.

 

Out of curiosity i did a few tests just to see what i was getting.

 

Nitrate=0

Phospate=.03ppm

Calcium=375

KH=10.2

Alkalinity=3.66

 

It was my understanding that ocean water has a calcium content well into the 400's and KH of around 9. This is not what i expected.

 

Granted im a beginner and not a chemist so i dont know how all the carbonate bi-carbonate calcium ions buffers interact and all that.

 

I think .03ppm Phosphate is pretty low and wont cause any algae problems.

 

My original plan is to use NSW to replenish trace elements to eliminate my need to dose them myself. I just wanted to know if these numbers are out of whack and would lead to some long term deficiencies.

[MrKrispy]

I did some tests on the Scripps NSW we get here in San Diego (free!!!) and the calcium has been under 400ppm both times I checked. I wouldn't worry about it. I wouldn't worry about it, even the Salifert test isn't accurate enough to worry about a 20ppm difference.

[silversurfer]

i use natural saltwater here in hawaii. we have this pipe that leads like 5 miles out to sea. ive tested this water and the Ca was above 400. natural sea water is the best

[stan]

I live near Half Moon Bay, CA (Mavericks Baby!!!) and we get purified water from there. Not lucky enough to get it free though.

 

I use the salifert tests and i kinda hate the "drop until water changes color" deal because i dont know if they want the very first occurence of a color change or a complete change.

 

Do you dose your tank or does it appear that the NSW is keeping your levels in an acceptable range?

[MrKrispy]

For my salifert tests I drip until it is actually blue, which is like 2 drops past purple. I think the difference is only 20ppm, so that is good enough.

 

I was adding b-ionic but don't like doing that because it is difficult to add slowly since I am sleeping at night. I am working on a kalk drip so I can get my Ca up around 43-450 in preparation for a clam...

[stan]

Yeah i notice that too. I basically take the first color change reading and the complete color change reading are figure it's somewhere in between the two.

 

Not familiar with using b-ionic but i was under the impression that it was simple to dose. Just measure and add.

 

Right now my tank is LR and Inverts only. No coral, no fish. I want to start adding some softies soon. I hope Ca=375 is going to suffice.

[markjd]

Originally posted by stan

I live near Half Moon Bay, CA (Mavericks Baby!!!) and we get purified water from there.  Not lucky enough to get it free though.

 

It's a small world. I live in the state of Victoria in Australia, and I collect my natural salt water from a place called Half Moon Bay

[MrKrispy]

stan,

 

if you monitor the pH of your tank with a probe (not a test kit) you can see it rocket up when you add the stuff. That is just when I added a a little bit, not the whole dose.

[stan]

small world MarkJD.. how cool is that? Maybe i'll start telling people im from Half Moon Bay, "Australia"... that sounds way more exotic.

 

MrKrispy: I see, so i assume dosing it has to be done sloooooow over a long period.

 

Well.. i guess i can only hope that my method for replenishing elements will work. I'll stay with it and keep testing. This dosing business sounds like a pain.

[markjd]

Originally posted by stan

small world MarkJD.. how cool is that?  Maybe i'll start telling people im from Half Moon Bay, "Australia"... that sounds way more exotic.

 

 

Might be more convincing with an Aussie accent

 

FWIW, the Half Moon Bay that I collect my water from is pretty tiny. There is a yacht club, surf club, beach, car park, boat ramp, jetty, sunken British warship, and a couple of stores. Probably only a kilometer of beach front surrounded by a cliff face of red and white limestone.

 

I collect my water from the jetty the old fashioned way: bucket and rope. I know another guy that collects from the bay that uses a bilge pump to fill up his water drums