Originally Posted by cccapt
With the Salifert kits, you add a drop and shake. I add the 1st 3/4 of the syringe pretty fast then slow down when I'm getting close to where I think I should be. Keep adding the drops until it stays blue. You may add a drop and it will start to turn, but when you shake it, it turns pink again.
I don't use RC, but from all I read about the problems lately with it, 350-360 seems about right. Check the mag. There have been issues with the mag being so low that people where sending in samples to them and they were getting full buckets in return. There is a huge discussion on ReefCentral about it here
Thanks for the link cccapt - lots o' reading there. I had heard about some "low" readings with RC, but not in the low 300 range. Yowsa. Made me go out and check my batch in the garage and it came in as it has for the last year and a half... 360ppm at 1.024. Although I'm a little nervous about the bucket I bought this summer that I haven't opened yet. Guess that's just a good reminder to test your source SW
when starting a new bucket.
But back to the original question... Josh, what I consider "normal" for RC is 360ppm at 1.024 SG
, alkalinity about 8-9 dkH
, and magnesium about 1140-1180 ppm
. That's mixed using DI
water. Sooo... I'd say your numbers aren't off at all.
As others have mentioned, sounds like you're not shaking the test tube after the last few drops if you're seeing a "layering" of colors. Using the Salifert test kit, I usually see the shift from pink to purple. It then usually only takes one more drop to make it turn blue completely, and that's where I call it quits.