LaMotte Ca test kit questions

[gflat65]

I've got a LaMotte Ca test kit that by code is still good. My question involves the color changing back to purple before going full on blue. I've been fighting the Ca/KH balance. My KH is finally almost up to 8 (running DSB). However, my Ca was over 600 a week ago and is still over 600, if I keep adding until the color changes to all blue and doesn't change back. I have a farily heavily stocked mixed tank, with more SPS than other types (LPS, softies, zoas, etc.~55%SPS/45%other). I have added no calcium over the last week and the value seems to have increased. I have been able to increase KH over the last week to tolerable levels. It's still low (7.8), but coming up.

How soon does your solution turn purple, then how long does it take for it to turn to blue without changing back to purple (in rough drop additions, etc.)? I dump all of the Hard #7 solution into the testing vial when I think I have completed the test and it turns a solid blue, which is more blue than I get when I think my test is completed. Am I missing something here? I just can't see how the Ca levels wouldn't go down over a week with all of the sps I have. I know Ca uptake can be inhibited under certain conditions, but 98% of my sps look great, so I don't think I have anything way out of whack, with exception to the super high Ca. Any ideas? TIA

 

[gflat65]

Anyone????? Buehler.....

 

[gflat65]

Wow. So no one out there uses LaMotte... Never would have thought that.

 

[Popeye]

I believe the instructions say that you should ignore a change back to purple after 5 seconds. You may be putting way too much of the #7 in and reading it as a higher Ca level than you actually have.

 

[gflat65]

I may have figured out my problem. I was gently swirling it, but stopped after the color change and it would almost immediately change back to purple until I was in the super high range. I ran another test yesterday and continued to swirl and it started taking a little longer than 5 seconds to change back, so I think the continued swirl was what I was missing. Now, it looks like I'm low on Ca... I'm gonna pull a sample and have someone with a Salifert check it to see how they compare.