New saltwater testing...

pdiehm · Jul 30, 2016

I am wasting my Saturday away...well not wasting but testing.

I have 15 gallons of water made up with Reefers Best, which by the way should be absolutely sued for false advertising....

And I have my old stand by regular Red Sea salt.

I made a gallon of regular Red Sea. 144.6 grams of salt per gallon.

How long should I wait to test new water? Do I hear it up to 77 before testing?

I just tested my Red Sea, at 68, the Alk was 9.3, way over the listed 7.8-8.2 at 1.0255 (1.026) on the bucket.

I am heating it up to 77...will that make a difference?

Randy Holmes-Farley · Jul 30, 2016

There's no need to heat before testing. As soon as it is clear you can test.

pdiehm · Jul 30, 2016

That's what I thought...

I just found this on the Red Sea site.

http://www.redseafish.com/wp-content/uploads/2013/12/10031-Red-Sea-Salt-manual.pdf

Retesting at 77F

Randy Holmes-Farley · Jul 30, 2016

pdiehm said:
That's what I thought...

I just found this on the Red Sea site.

http://www.redseafish.com/wp-content/uploads/2013/12/10031-Red-Sea-Salt-manual.pdf

Retesting at 77F

It won't matter. The settling of the water is far more important than temp for this sort of test.

pdiehm · Jul 30, 2016

Well at 68F my salinity was 34ppt. At 77, it is 30.

I find this very interesting. Wondering if I need to start warming up the temps to 77F before adding salt.

I didn't believe it, so I recalibrated the digital refractometer and retested. Another 30 reading

nitro316 · Jul 30, 2016

Specific Gravity does change with temperature as water can become more or less dense.

pdiehm · Jul 30, 2016

Ok at 1.024 regular Red Sea tested at 8.7 Alk. Should be in the 7.3-7.7 range if I recall.

New test coming up. New batch of a gallon.

pdiehm · Jul 30, 2016

My first test is invalid. The bucket says those parameters are based on 2.5 gallons rodi. Just made 2.5 gallons, waiting for it to mix clear, throwing in heater and will test at 77F

Randy Holmes-Farley · Jul 31, 2016

pdiehm said:
Well at 68F my salinity was 34ppt. At 77, it is 30.

I find this very interesting. Wondering if I need to start warming up the temps to 77F before adding salt.

I didn't believe it, so I recalibrated the digital refractometer and retested. Another 30 reading

That is a measurement problem. Salinity does not change with temperature, and while the methods are often temperature sensitive and they either autocorrect for temp (many do) or they need to be corrected manually.

Which refractometer?

Randy Holmes-Farley · Jul 31, 2016

nitro316 said:
Specific Gravity does change with temperature as water can become more or less dense.

Well sort of. It becomes more or less dense, but specific gravity is the ratio of the density of the seawater to fresh water at the same temp. Both change very similarly, so specific gravity of seawater changes only a tiny bit with temperature.

pdiehm · Jul 31, 2016

Randy Holmes-Farley said:
That is a measurement problem. Salinity does not change with temperature, and while the methods are often temperature sensitive and they either autocorrect for temp (many do) or they need to be corrected manually.

Which refractometer?

Milwaukee Digital