Reef nutrition

Help for the color blind!

Scarbird

Scarbird

Supporting Member
BARcard
Please help!
I have been using Salifert test kits for a loooong time.
I just tested the standard from BAR and my results show 11.5 (see pic below)
The first pic is the sample with the 4 drops of the green stuff.
Second pic is where the standard should be (10.884 KH).
Third pic is where I usualy call the results (11.5 KH).
Salifert instructions say: Continue to add drops until sample changes from a blue-green to an orange-red or pink color.
The test kit date is 2016.
Hopefuly someone can set me straight here. Should I be using another brand of test kit or am I color blind?
Heeelp!

John

Attached files /attachments/sites/default/files/KH colors 002.JPG /attachments/sites/default/files/KH colors 003.JPG /attachments/sites/default/files/KH colors 004.JPG
 
first pic is clearly green, second is a muted blue, third is purple (from what it looks like in the pic) camera might not translate the color perfectly but if it is slightly purple to your eye it might take another drop to get to pink. I have a fresh API kit, if you like I can test the BAR standard I have & let you know what I get.
 
HiFidelity said:
I have a fresh API kit, if you like I can test the BAR standard I have & let you know what I get.
Click to expand...

That would be cool if you could do that. I'm thinking that the standard is spot on. I believe David said they had it lab tested. I'd like to know what the various test kits are reading. I'll test my Red Sea kit tonight when I get home.

~Charlie
 
Piper said:
HiFidelity said:
I have a fresh API kit, if you like I can test the BAR standard I have & let you know what I get.
Click to expand...

That would be cool if you could do that. I'm thinking that the standard is spot on. I believe David said they had it lab tested. I'd like to know what the various test kits are reading. I'll test my Red Sea kit tonight when I get home.

~Charlie
Click to expand...
Thanks guys, much appreciated!
John
 
Coral reefer said:
With the salifert, make sure you shake the dropper bottle real good before use, and hold it completely vertical while adding the drops...
Click to expand...

Sure thing, Ill try again after work.
 
Scarbird said:
Second pic is where the standard should be (10.884 KH).
Third pic is where I usualy call the results (11.5 KH).
Click to expand...

Actually, John, I think your results are not bad, considering that it is approximately a 5% error! The Hanna Alkalinity Checker also has a +/- 5% error. Frankly 5% is pretty good for a hobbyist test kit that costs around $20, compared to lab tests using machines that cost thousands of dollars. :)

The idea behind providing the alkalinity standard is to help you calibrate your readings. Going forward, you can assume that your Salifert kit is reading approximately 0.6 dKH higher than the actual alkalinity, so you would subtract 0.6 dKH from your Salifert measurement to obtain the "actual" alkalinity. Ideally you would calibrate before each test (and we do have extra bottles of the alkalinity standard if you want to go down that route ;)), but IMO it is more important to maintain stability than to target a specific number.
 
Yes. Your tank seems to be doing well so keep up what your doing. Don't chase numbers. Whatever your kits are reading aim for those numbers to stay the same (ish)
 
Thanks for the feedback.
My main goal is to determine at what color I should be calling the results.
Previously, I called the results at pic#3, now it seems like I should be calling the results at pic #2.
Do my fellow reefers call at the same color(s)?
 
Scarbird said:
Thanks for the feedback.
My main goal is to determine at what color I should be calling the results.
Previously, I called the results at pic#3, now it seems like I should be calling the results at pic #2.
Do my fellow reefers call at the same color(s)?
Click to expand...

I want to know too, the instructions aren't super clear at which shade of color you should stop adding drops. My API says keep adding till the color turns green, well that's great! it starts turning lime green at first, then you add a little more & becomes more & more regular green, so I stop when the color starts changing or when it turns true green? I'm always worried about measuring one drop too high or one drop too low which says the result by more than 5% :~
 
rygh said:
Why not get a Hanna digital Alkalinity meter?
No colors to worry about ever again.
Only $50, which is about the cost of two Salifert kits.
Mine has been working great. Other than the minor annoyance of reading out in PPM.

http://www.marinedepot.com/Hanna_Instruments_Checker_Colorimeter_Single_Item_Monitors_Controllers_for_Saltwater_Aquariums-Hanna_Instruments-HN1181-FITEMOID-vi.html
Click to expand...
I picked up the PO4 one and I'm glad I did. At some point, I may just got all digital, if that's even possible.
 
API kit exp. 08/2017
11 drops = 11 dKH
KH standard is 10.884 dKH

on last drop it changed to lime green/yellow which means I've been recording 1 dKH higher than what my tank actually is so I'm very glad I did this check, going to adjust procedure from now on.
 
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