SeaTest Calcium Test Kit

[kevin01]

I know other Reef Enthusiasts out there use this Test Kit.
I just recently got into the kick of giving my Coraline a jump start, before Christmas, Metal Haildes, and pretty inverts. My first move was supplemental Calcium additive to obtain the recommended 410mg/L. I am also adding SeaChem Vitamin Supplement. I chose the SeaTest test kit because it has a pretty good resolution, 15mg/L. Now I am having a problem, the instructions say add drops until the solution turns blue, but I have no idea how blue is blue. The solution does make a quick color change at about 21 drops but is not really blue, more of a semi-dark purple. Is this the number of drops I should use?? I have thrown two bottles of the SeaChem Reef Complete at 160,000mg/L Ca in at 25mg/L every other day and also use SeaChem Reef Calcium 50,000mg/L polygluconate Ca twice a week. Yet, everytime I test I measure 21 or 22 drops which corresponds to 315-330mg/L Ca in my tank. Is it possible that the tank is consuming Ca that fast, (The Coraline is growing quite quickly) or is my measurement off? I don't suppose anyone has a photo of the correct color...
Thank you,
Kevin
Tank info:
-Future Black Sand Reef, currently have Yellow Head Goby, Cleaner Shrimp, Various Hermits and Snails
-55 Oceanic - 25 Gal Rubermaid Sump
-SeaClone Skimmer, Merlin Biological, Fluval 404 Mechanical/Carbon/Biological, MaxiJet 1000 for O2 exchange and 1" LS
-60W NO flour one 50/50 and one 10000K daylight
-Trying to grow in 20 of 30lbs LR

 

[@knight]

my test kits do that. i think the test is accurate. keep adding calcium. it may take a few weeks after dosing before numbers will rise.

 

[adrian]

I used that sea test kit several times and never did get a reliable reading. I say as soon as it changes color, whether it be purple or blue, and does not quickly turn back to pink, that would be your best bet at a good reading. Next time try a salifert, it turns baby blue with no problem. Are you boosting you alk and monitoring your pH as you try to raise the Ca? The three are realated, and its hard to get one to an appropriate level if the other two are not stable. HTH
[ November 26, 2001: Message edited by: Adrian ]

 

[kevin01]

Yes, I am using an 8.3 pH buffer to keep the pH correct. Last night while viewing the tank it appeared to be snowing (calcium precipitating) but they could have been small bubbles.

 

[jmsullivan]

I use the same test kit and mine turns purple too, I've found that if you keep adding drops it will turn blue which will give you a higher rating, mine reads low too about 390. I would do a test and then take a sample to a lfs,(I know mine does Ca test)Maybe you could compare to the two. Good luck.

 

[jagster]

I've had the same problem with other calcium test kits. To be conservative, I always used the initial change to purple. Since, I've started using the SeaChem Reef Status kits. They're a bit $$, but there is no question of when the color change occurs.