Api test kits

#1
Just purchased the API reef test kit. I have read somewhere before and have noticed again that the 5ml line on the test tube is not really 5ml. I put 5ml in my syringe and put it in the test tube,and it is approx. 1ml over the line. In other words the line is about 4ml. Which with Kh means it's off by that much. So. 7.5Dkh on the test tube line that says 5ml and 10Dkh with the actual 5ml in it. WTF? Anyone know?
 

rjl45

Clown Fish
#2
API test tubes are natoriously inaccurate and part of the reason the API test is not highly regarded. Additionally, the tests themselves are not very accurate. If you need accurate numbers, take a sample to your LFS, or buy the Safilert or Red Sea tests. I have heard good things about both, and haven't developed an opinion myself.

In my opinion, if you are simply looking for indicators or general trends, API tests will be ok.
 

SkyShark

Dolphin
M.A.S.C Club Member
#3
Make sure you are referencing the meniscus and not where the water seems to "reach" up the walls of the vial. The syringe is the easiest way to pull out 5 mls.
 

SynDen

Administrator
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#4
I only use API tests for ammonia,nitrates and ph which I rarely use but when I do I use the 5ml syringe from my red sea test kits ;)
 
#5
I always wondered about the 5ml mark for the api tests. Its for sure not accurate. I still use the API tests for dkh and calc for consistency. I love all the Salifert test kits though.
 

that0neguy1126

Registered Users
M.A.S.C Club Member
#6
Never trusted the API vials. Always use a syringe. I switched over to the Red Seas kits because int he long run they are cheaper to refil and easy to read.
 

Walter White

Reef Shark
M.A.S.C Club Member
#7
Ha this is funny I only use API for testing alk. I never use the 5ml vial because shaking or swirling it sucks. I have always used a 5ml syringe and added it to an old salifert test sylinder. I have always gotten very similar results to the Hanna checker. I use the Hanna checker every couple months just be sure I'm still getting expected readings.

All that said I think API is fine just for measuring relative delta from one week to the next. If you want a more accurate baseline buy or borrow a more accurate test kit. Week to week testing is just easier with API to make sure I'm not seeing any swings.
 
#9
I am using Salifet for Alk and Mag, consistently getting accurate readings for Ca with the API. For my puposes, being that I do a 5%-10% water change weekly and use Fritz PRO RPM, all my parameters, especially Mag, are good if not a little elevated.
 
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