? about CYA extended test kit directions

[bbrock]

Read this on the Extended Test Kit Directions re: CYA testing:
•If you are using the large view tube and know that your CYA level is at least 50, you can use half as much pool water and half as much R-0013 to save on reagent.

I have the lg tube from the TF100 and tried to implement this, but I don't think it worked right. I assumed to "use half as much pool water" that I would estimate this by filling with water halway between the lower mark and the bottom of the bottle, and "half as much R-0013" that I would then fill up to the lower mark. I can't recall what the results were, but I remember it did not mesh up with what it had been the day before. Therefore, can anyone, or you Jason, explain what was meant by the above bullet?

Tx.

 

[JasonLion]

What you describe should have worked.

Normally the CYA test is done with roughly 24 ml total in the mixing bottle, 12 ml of pool water and 12 ml of reagent. To do the 50+ CYA test you use roughly 6 ml of pool water and 6 ml of reagent, which together should fill the mixing bottle to the half way mark. It doesn't have to be exactly 6 ml, but the two amounts (pool water and reagent) need to be equal.

 

[bridgman]

I guess the trick would be to measure 6ml and add another mark to the bottle, to make sure you get exactly the same amounts of water & reagent.

Another option might be to score one of the smaller CYA bottles from the Taylor K2006 kit -- IIRC they are marked for 7ml of pool water and 7ml of reagent.

 

[Dmsattelberg]

You could alway buy a cheap graduated cylinder from a lab shop, online, or ebay

 

[bbrock]

good ideas!

i have access to medical supplies so I can use a 10 cc syringe if I want to be exact. not sure if it will pose a problem with the test, but my CYA is holding pretty much at 50. This was determined when I use the full samle size (10 ml) as mentioned in my test kit TF100. As I am a noob, the level could be a little more. I run the CYA test and as the extended test kit directions state I put it back in the mixing bottle and try again. basically, 50 seems to be the avg. that I get. 55 a couple of times, 50 at others. so, i will settle on 50. so, with a level of 50, not sure if this version of doing the CYA test would work since Jason was stating that CYA needs to be 50+.