ed99, you won't get true numbers at 1.022. Seawater in the wild is 1.026 and this difference (I suspect) will cause you to get lower alk values than those at 1.026

I'm almost certain you're right- alk should be a function of concentration. I made this batch a little weak because I'm filling a new tank that is a little high on SG. I've got another batch brewing, I'll check it tomorrow.

ALthough I'm sure going up to 1.026 isn't going to put your alk at 14 like mine. I suspect you'll get about 9 dKH

Well this gets more interesting and might explain a water change tragedy that I had awile back ...

Using Salifert test kits ( salinity of 35 ppm ) I got a dKH of 18.24 and calcium of just 290 :eek:


I will continue to mix for a couple days and retest it.

Cheers

O.K. Brad,
I just finshed testing a sample gallon, using salt from my bucket of I/O that I purchased last Xmas. I already did my waterchange last week so I was curious to see the results :cool:
The results are as follows:

SG=1.023

Temp=77F

PH=8.43

KH=14.4

Cal=325ppm

I tested each reading twice, just for peace of mind :mrgreen:
Now, in this thread you said that your value was sitting alittle high at 14dKH as is mine, wouldn't you say it's alot high if natural sea water is at around 8dKH? My value seems to drop to about 7-9dKH after a few days.
My dKH right now in the reef is reading an all time low of 2.6dKH, and the weird thing is, I just did my 20% waterchange last week and dripped my top off with Kalk a few days ago :confused:

cheers, Rich

My pail of salt is a few months old and it checks out okay. How old is your bucket Rasta? What happend after the water change?

http://www.canreef.com/phpBB2/viewtopic.php?t=5573

The 30 gallons would have represented a bit less than 10% the total water volume ... When I poured the replacement water in it was right over where my shrimp liked to hang out in the rockwork on right side of my tank :frown:

It was a brand new bucket at the time of that water change :eek:

Cheers

Rich, your SG is a bit low, which could explain the low Ca(although that is pretty low). The pH is higher than I normally find new water. Although 14 is a lot higher than 8 dKH, it isn't a lot in the big picture. My tank has run at 14 long term without issue.
If this is just a test gallon, can you add a bit more salt to get it up to 1.026? Then we can look at the numbers on par with the other results.

Rasta, that would make sense. July 27th you posted but I think I bought my bucket a few months before that. I think this is a wierd batch of IO that came through the plant. I've had no problems with IO and i've used it from day one of my first SW tank. I'm halfway on my sixth bucket and now I'm gonna be nervous with my 7th but I really do like IO.

Brad, I have been keeping my SG at 1.023 for 6 years now with no ill effects. I dumped the 1gl of new water into the sump after I finished testing. So I will mix up a new 1gl bucket in a day or two and do the test again at the higher SG.

cheers, Rich