Adding 3-5 at a time for the first 3/4s of the drops has no downside. It is the volume of drops added that matters not how you add them.
Swirling by hand can be done, but it is much harder to do than using a speed-stir or smart-stir.
Swirling by hand makes it job, while using a speed-stir makes it almost "fun".
Agreed! First, if you know you will be adding 10 drops or so, the first 3 to 4 in the vial, even if you were swirling by hand wouldn't change the color. The total number of drops is important and as you get towards the end, will start seeing flashes of color before the final drop.
I'd get t
he sale one if I needed a stirrer.
Any one of those stirrers will work great, but for $10 off the normal price for the blue one, seems like a good deal. That one is on sale because the LED is the wrong color and could make it difficult to read some tests. The Taylor smart stir, and the other brand that comes with the TFTest Kit Pro has a while led light on the base, whereas the one on clearance linked above has a blue led. Again, the blue led is not best for all the TF testing, if you need the LED to help you. If you do not use or need the LED, like me, the blue one may fit your needs just fine. Apparently, TF Tests got these in and maybe didn't expect the led to be blue so in order to move them, they need to discount them. It will stir just like the others, which is what I love. I can't image swirling all these tests by hand once you have had one of these. For a very small price in comparison to everything you spend on your pool, this is so worth it.
I would also order a few extra magnets. The one that comes with it could be misplaced, dropped, or just lost, and for an extra 6 bucks each, or if you go with the regular pills, 8 bucks for 4 like i did, great to have a few extra.