What effect does salinity have on test results ?

[Lesely]

HI all,I am fairly new to all this and am a wondering (thought I read it some where) what affect salinity has on your test kit readings.
Is it true that if your salinity is at 1.023 you will get different readings than if is at 1.025 ?
If so are the results of mag, cal and alk going to be higher or lower than the test kit suggests.
The reason I ask it my parameters are all testing well but my salinity is 1.023 (a bit low ) If i slowly raise this with ATO water to 1.025 will this affect my readings.
At the moment
ph. 8.3
alk 8.9
cal 420
mag 1250
temp 26
Thanks

 

[ccCapt]

You will get different readings at different salinities. Going from 1.023 to 1.025 will slightly raise your alk, calcium and mag, but it won't be a very big difference. Higher salinity means more salt is used when mixing. More salt means higher levels.

 

[Lesely]

You will get different readings at different salinities. Going from 1.023 to 1.025 will slightly raise your alk, calcium and mag, but it won't be a very big difference. Higher salinity means more salt is used when mixing. More salt means higher levels.

Cool thanks. So more salt means more trace elements (makes sense) So its not the salinity reading that actually directly effects the test kit readings which is how I had interpreted the article.
The test kit readings will be actual numbers and only go up because the ATO is saltwater with trace elements ?
I am such a dummy.
All makes sense now.
Is 1.023 a real problem, should I bother correcting it ? Or just wait till the next water change, make it a little higher and do it that way ?

 

[emmett0122]

all your numbers look good and as long as everything is happy 1.023 should be ok imo but if you want to raise it do it slow

 

[ccCapt]

The average salinity on the reefs around the world is 35 ppt or 1.026 SG. Being salinity is probably the easiest parameter to control, there is no reason to keep it any lower than what is natural.
What are you using to test your salinity? Hydrometer or refractometer?
Here's a few good articles you can read.
http://www.reefkeeping.com/issues/2004-05/rhf/index.php
http://www.ronshimek.com/salinity_temperature.html
"Coral reefs are generally located in areas that have salinities in the range of 35 ppt to 38 ppt. Most of our corals, and the associated fauna including fishes, will live best at those conditions (Weber and White 1976). Most organisms, even osmoconformers, can survive for brief periods in salinities well outside their normal range. But if maintained for longer period outside of that range they will be stressed and eventually will become so damaged that they will die even if returned to their normal salinity. Higher salinity is slightly more tolerable to these animals than is lower salinity, and adult animals are more able to withstand the extremes than are the juveniles or larvae."

 

[Lesely]

Thanks a lot for the info very imformative articles on other things as well. I normally keep it at 1.025 but for some reason my skimmer wet skimmed (and I mean wet) over the last few weeks and the ATO topped off far more water than normal. I did a 200liter change last weekend which I now realize I should perhaps made slightly higher to raise it. I have now made a new batch of saltwater and I am running in my ATO until salinity rises back to normal levels. Thanks for all your help much appreciated. There is so much still to learn, i feel like I could be in this hobby for 20 yrs and still be learning. lol