Chemistry Issues..

[SmallFry]

Originally Posted by Aquattro

Pretty sure that test value is wrong. at that pm, your Ca would precipitate. Something in the water could be affecting test results.

I see your point, I thought the test was wrong too, the test on the fresh batch of water is what got me thinking again.
I hadn't considered something else in the aquarium water could be affecting the results. What that might be is an interesting and a little worrying question though..