Salinity levels

[gpohly]

Since starting my tank in August, I have been maintining salinity in my tank at 1.024SG @ 80 F. 2 months ago, I switched my weekly water changing routine from making water using RO water and IO, and began using the filtered seawater available for free from the Scripps Oceanographic Institute.

When I warm the Scripps water to 80F, it is always 1.026 SG. I have been "cutting" it w/ RO to a SG of 1.024 to match my tank, but I have to wonder: If the water coming from the ocean is 1.026, why am I keeping my reef at 1.024, and will it matter?

Glenn

1.026 is typical for NSW

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I thought I was me, but we were wrong
email: geeflipr@internetcds.com

[gpohly]

Thanks, Doug.

Does this mean it's also OK for my tank? Since I top off w/ RO, cutting the NSW first isn't a big deal and I don't have to worry about increases above 1.026 due to natural evaporation before I add RO. (I add an average of 1/2 gal per day, in a 75-gal total system.)

But now out of curiosity, what is the general accepted practice for SG range in the reef tank community?

[bill-e]

I keep mine at 1.026. I wouldnt think that .5 gal of evap in a 75 would matter much as far as salinity is concerned.

[bmw]

Not only would I keep it at 1.026, I would keep it higher--tell you why.
DOCs (disolved organic chemicals) will raise the reading of a hydrometer without raising the actual salinity of the water. Not a problem in the ocean, but a very real factor in small boxes of water(that reads 20,000gal or less by my biology friends). That reading can vary according to how you keep your tank.
With a hydrometer reading of 1.025 say, you might very well have an actual salinity far less than would be natural. Can't do any better with an electonic device or refractometer either-affects them all.
FWIW.
b.

Interesting, I have long wondered about the effects of large amounts of kal or some of the 2 part calcium/akl products

------------------
I thought I was me, but we were wrong
email: geeflipr@internetcds.com