Salifert Calcium Tester question!

[pcurry18]

I am using a Salifert Calcium test and following the directions to the tee. When adding the final drops, it tells you to look for the pink liquid to turn clear blue. Does this mean all of the pink liquid or are you supposed to stop once you see a hint of clear blue.

This is the deal, after adding all my drops only 3/4 of the pink liquid in the test jar turn blue. the remainer 1/4 stays pink..I know im not supposed to swirl or shake when im adding these drops. This is confusing me and any clarification would be great.

At one time, all the liquid turned blue but here lately im getting only 3/4 of it. whats the skinny on this. can you help? I did a water change the other night and tested again today and still the same. I think my ca might be to high! How do i lower it!

Thanks for any thoughts!

 

[MrMikeB]

Hey Paul,

I use this test kit too. The way it works is that you keep adding a couple drops of the solution via the 1ML tube, swirling (yes, do swirl) after each drop when you are getting closer to the actual value. Where did you read not swirl after each drop?

The solution in the vial will turn from pink, to a purple, then to a blue. When it is no longer purple (and no longer has the red from the pink), that is 'clear blue.' Take your reading at that point. I use a white backdrop to look at when I am testing to be sure I can tell the difference in colors.

If you are not turning blue at all and the 1ML tube is empty, then your readings are over 500PPM for Ca - probably a bit too high (assuming you are testing correctly). I would recommend successive water changes (say 20% each day) until it drops down to where it is supposed to be. Too quick a change of any parameters are not good, so be patient. What are you dosing with to get the Ca that high?

Hope this helps!

 

[DrDNA]

Yep, like MrMikeB said, it sounds like you aren't swirling it while adding the drop-by-drop solution, hence the "three-quarters blue and one-quarter pink". I use the same Salifert test you do. You keep dripping in the solution (Ca-2 or Ca-3 or something?) and swirling, then within one or two drops, it will change to a clear blue color, the color change is fast and real obvious when done correctly.
Good luck!
Jeff

 

[edsimmons]

i think it sayes swirl 1-2 seconds after every drop.

 

[pcurry18]

I must have some bad instructions cuz it only says to swirl for 10 seconds after adding the CA-2 regent. So im off to test the correct way now...thanks a bunch.

The only thing i have added was purple up every other day or so, and i half dose it. I really dont like additives....so , ill get back with you on the results. Thanks again.

 

[pcurry18]

ok, after testing correctly, it did as you said, it went from pink to purple to blue on a white background. the piston was at 0.2 so the chart says 400 is this too low you think?

 

[plankton]

1. take 2 ml sample from tank
2. add level scope of ca-1 (don't swirl)
3. add 8 drops of ca-2 (swirl for 10 seconds)
4. titrate alloquotes of ca-3 until a nice solid blue color forms (normally 2-3 drops from purple). swirl for 1-2 second in between each alloquot. When you initially draw CA-3 just pull solution till the black plunger hits the 1.0ml mark. Don't worry if there is air because that is expected. Make sure you put the tip on the pipet/syringe.

400ppm Ca fine.

More importantly, how is your Alk? Then, how's your magnesium?

Scott

 

[pcurry18]

Scott,

Thanks, i tested KH which was 11.2 and Alkalinity was 4.00. The color turned pink with the piston at 0.3.

Are these on target?

 

[Reefugee]

A little tip: It's hard to see the color change. Before you do the titration - add 4 ml of RODI water to the vial. It will be much easier to see the color change.

 

[plankton]

> KH which was 11.2 and Alkalinity was 4.00

11.2 dhk, 4.00 meq/l is a bit high so watch it especially if you are dosing baking soda or some other additive.

Scott

 

[pcurry18]

what the heck do i use baking soda for? will that lower the KH and stuff

 

[plankton]

Use baking Soda to raise alk. Do nothing and Alk will drop by itself as your system produces acid through normal biological processes.

Here are some good articles by Randy to read

 

[CaliforniaDreamer]

Baking soda raises the alkalinity but also lowers the ph a bit (at least temporarily). Washing soda raises the alkalinity but also raises the ph (this affect also tends to be temporary). Baking soda is sodium bicarbonate which is washing soda (sodium carbonate) which has absorbed carbon dioxide. You can create washing soda by baking in a shallow glass container baking soda in a 300 degree oven for about 1 hour, this will drive off the carbon dioxide. If your tank tends to have a low ph (7.9-8.2) use washing soda to adjust alkalinity. If your tank tends to have a high ph (8.4 or so) use baking soda. Randy has a number of articles on this chemistry in his Reef Chemistry forum here on Reef Central.