Benchmarking a possibly-expired test kit

[FormerBromineUser]

Is your current bottle labelled R-0007? If so, then those are just different quantities of the same concentration. You want A, C, or D; 0.75oz, 2oz, and 4oz respectively.
The cost goes down as the quantity goes up, just like most product packaging. It boils down to what the pool store carries as Taylor is tough to get in Canada. Make sure they have TAYLOR R-0007.

[Whetstone613]

Yes, one of them is "R-0007 THIOSOLFATE N/10". Since but I don't usually use half of a bottle in one season, I might as well get the smallest. As for the concentration: if it's Taylor, it's the right concentration and if it isn't, it's anybody's guess?

[FormerBromineUser]

You are good if they have TAYLOR R-0007. If they are Taylor reagents and the numbers match, you are good. The letters after R-0007A or R-0007C are just the size designation.

[Whetstone613]

I called Taylor to ask how I know if their reagents are expired, and by using the lot numbers, they were just able to tell me what it is due to expire. Fortunately, everything I have here is good for another season, except the R-0002. I called one local pool store, and they have some Taylor there, but because they don't sell the small bottles, it's more than I want to pay for a single reagent. The thing is, according to http://www.taylortechnologies.com/Ch...SP?ContentID=2 it should be taking on colour to be expired, and the stuff is still clear. So I'm not totally sure what to think.

[CarlD]

I guess I don't see what the problem is with testing.

You can add 1ml of your LC to 10 liters of tap water (5 x 2 liter soda bottles into a 5 gallon bucket) and it will give you the concentration.

The idea is that if you do the math, adding 1 gallon of LC to 10,000 gallons of water (or 1 liter of LC to 10,000 liters) the water's FC will be increased by exactly the concentration of the LC, whether it's regular bleach, ultra or LC (5.25%==>5.25ppm of FC, 6%==>6ppm of FC, 12.5%==> 12.5ppm of FC).
Scaling down to 1 ml of LC to 10,000 ml of water (10 liters) gives the same relationship. And 10 liters is 5 Coke/Pepsi bottles.

Just remember to subtract any FC the tap water has from you calculation.

[Whetstone613]

So I bought another R-0002 and tested the chlorine w/both bottles. They showed the exact same result, so I guess it was a waste of 10$. Fortunately, it was only 10$ (and in CAD). Several other stores wanted the high end of 20$ for that 2oz bottle--nearly the cost of a new kit. 'Really pays to show around!