Tested my Salinity and,...

Wiskey · 12-15-2006, 11:06 AM

It measured 1.031, OOPS!

I was wondering why a couple of my corals were looking a little off. A warning to everyone who uses the DIY 2 (3) part, it is also slowly adding salt, the more you use, the quicker this happens, especially if you are trying to raise Mg a long way.

I really need to test that more often, looking at my book the last time I tested salinity was about 3 months ago. I test CA/ALK every week though.

Whiskey

tashier · 12-15-2006, 11:10 AM

Ouch. You'll be lowering it slowly?

Wiskey · 12-15-2006, 11:13 AM

No, well sortof, I just drained 10G from the tank and let the ATO deal with it, ATO is rather slow (on purpose).

I think it should be around 1.026 or 1.027 when I get home today. I might have to drain more water still.

Whiskey

Spanky · 12-15-2006, 11:14 AM

density = specific gravity

BTW specific gravity means more than salinity.

Wiskey · 12-15-2006, 11:42 AM

Quote:

Originally Posted by Spanky

density = specific gravity

BTW specific gravity means more than salinity.

Sorry. Salinity of about 40 PPT.

On my refracto it's all printed on the same scale, so it doesn't make much difference, but if I had one of the floating bulb type SG meters I would agree.

Whiskey

Spanky · 12-15-2006, 11:45 AM

refractometers measure the salt content. There are other things that will change specific gravity.

Specific gravity is more important to animals that live in salt water.

Remember the old gimick about adding sugar so you could keep fresh and salt water fish together?

Wiskey · 12-15-2006, 11:55 AM

Quote:

Originally Posted by Spanky

refractometers measure the salt content. There are other things that will change specific gravity.

That's what I mean, no matter which scale I read on my Refracto it's still measuring salt content. If I had the floating bulb type SG meter however, it wouldn't be just measuring the salt content, it would be measuring density, and all the everything in salt water. IE, magnesium changes the Density, it doesn't change the salt content.

Quote:

Remember the old gimick about adding sugar so you could keep fresh and salt water fish together?

No I don't

This one I never heard, care to explain?

Whiskey

Weatherman · 12-15-2006, 12:24 PM

Have you calibrated your refractometer recently?

If you have one of the Captive Purity ones (the ones with the black handles), you can calibrate it using RO/DI water. Apparently some of the cheaper models need to be calibrated to a solution closer to 35 ppt. If they are calibrated to measure 1.000 with RO/DI water the values around 35 ppt are off.

I forgot to calibrate my refractometer and discovered about a month ago that it was measuring around 0.003 too high (I thought my tank water was 1.026 and it was really 1.023. I let the water readadjust on its own by stopping the fresh water topoff drip and replacing evaporated water with new saltwater. What a pain that was. I use the fresh water topoff to add Ca(OH)2. I had to dose two-part for several days to keep my Ca and alk levels in line.

By the way... Everything you ever wanted to know about refractometers:

http://reefkeeping.com/issues/2006-12/rhf/index.php

tdwyatt · 12-15-2006, 02:06 PM

with fishes, SG is the issue as well as osmolarity (why you can use sugar to affect osmolarity for creatures that need stable highly osmolar environments), however, corals find more issues with the actual composition of the seawater, i.e., the conservative element proportionality in regards to their function for both calcium and alkalinity/bicarbonate physiology...

This is the same reason humans can use D5W for IV volume relacement as they can NS. Also why there is an issue with crystalloids Vs. colloids, but that is not really related to this discussion...

DevilBoy · 12-15-2006, 02:10 PM

Quote:

Originally Posted by Wiskey

It measured 1.031, OOPS!

I was wondering why a couple of my corals were looking a little off. A warning to everyone who uses the DIY 2 (3) part, it is also slowly adding salt, the more you use, the quicker this happens, especially if you are trying to raise Mg a long way.

I really need to test that more often, looking at my book the last time I tested salinity was about 3 months ago. I test CA/ALK every week though.

Whiskey

oops!!

tashier · 12-15-2006, 04:53 PM

Quote:

Originally Posted by tdwyatt

with fishes, SG is the issue as well as osmolarity (why you can use sugar to affect osmolarity for creatures that need stable highly osmolar environments), however, corals find more issues with the actual composition of the seawater, i.e., the conservative element proportionality in regards to their function for both calcium and alkalinity/bicarbonate physiology...

This is the same reason humans can use D5W for IV volume relacement as they can NS. Also why there is an issue with crystalloids Vs. colloids, but that is not really related to this discussion...

That absolutely went right over my head....

jph · 12-15-2006, 05:12 PM

Quote:

Originally Posted by tashier

That absolutely went right over my head....

i was about to say the same

glad that i'm not the only one

J.

Wiskey · 12-15-2006, 05:29 PM

Quote:

Originally Posted by tashier

That absolutely went right over my head....

I think he's saying that the corals care more about the makeup of the sea water, elements in porportion to each other.

Fish care about the salinity itself.

But I could be wrong.

Whiskey

Wiskey · 12-15-2006, 05:30 PM

Quote:

Originally Posted by DevilBoy

oops!!

Yep! Oops, definitally, definitally, Oops.

Whiskey

Casey · 12-15-2006, 05:32 PM

Tom care to put that in laymens terms for us idiots.