Water testing 'old' water

[suphew]

I'm currently living a few hours drive away from my reef tank and my partner is looking after it. My Calcium reactor media ran out, and my parameters appear to have gotten very low (Ca=290ppm Kh=4.5dKh). I refilled my reactor (Korallin 1501) 3 weeks ago and have that running using my usual drip rate etc, I also have a PH meter testing the output. My partner has also been adding baking soda, and Calcium Chloride, over about a week, to what according to a reef calculator should have brought the levels back up.
However when I retested the water the levels have hardly moved, particularly the Kh? (Ca=350ppm, Kh=4.6dKh). My Mg was also a little low, but I corrected this a couple of weeks ago and it is now 1500ppm.

I was surprised at how low the the orginal readings were and am more surprised that they haven't risen significantly with the amount of chemicals added.

What I am wondering is if the parameters of the water I'm testing will have been affected it sitting in a small sealed container for 24 hours or so while it comes to me? My partner says she wont do water tests :rolleyes:

The only other thing I can think of is that the tank does have a high calcium demand (large clams, sps, etc) is it possible that the tank would be using a lot more calcium because it has lacked it for a few weeks?? i.e. a catch up?

[HowardW]

<<< What I am wondering is if the parameters of the water I'm testing will have been affected it sitting in a small sealed container for 24 hours or so while it comes to me? >>>


That should have no real effect on your test results unless there is significant evaporation or the container is leaching something into the water sample, and either possibility seems remote.

[bertoni]

If the temperature was kept within bounds, the alkalinity and calcium should be okay, but precipitation is possible if the sample gets heated. The pH reading would likely be useless.

[suphew]

Cheers, I might try and see if I can borrow another test kit, maybe thats the problem.

Other than using my pinpoint to test and setup my cal reactor I haven't tested PH for years. Once I saw the amount it changed during the day using an electronic meter I realised it was pointless.