I'm pretty sure the pool stores use the drop-based kits for testing. I know my PB does, they use the Taylor kit. We have the TF100 kit which uses the Taylor reagents but packaged in better quantities then you get with the Taylor kits (link below). You can also buy salt test strips from them. The TF100 kit comes with great instructions, it's quite easy to use. We run the full tests every 2 weeks and chlorine/ PH avery 3 days or so.

Here is a link that might be useful: http://www.tftestkits.com/

Pool with no harmfull chemicals
Our Pool (10000gallon) 12' * 32' *4' has no added chemicals and we use it every day.

To handle the water we use a Superior Aqua System and a carbon filter (Clean Water Systems model 7000) Cleanwaterstore on a bypass(15 galon per minute through the carbon filter).

Each week we add 1gal off 35% food-grade H2O2 (Hydrogen-Peroxide) from purehealthsystems.com and vacuum the pool and clean the liner above the water with a sponge. (We buy a 55 Gallon drum each year that cuts the cost.)

To heat the pool on colder weather we have a Aqua Cal Heat pump (Ice Breaker H100R model) and a gas heater for very cold times.

To eliminate heat loss from evaporation we cover the water with a pool cover, it saves about 50% of the heating energy.

We use our pool 365 days a year, to be able to do that we got our pool enclosure from Aqua Shield, it is great, it can be moved to the side in the summer for swimming and it keeps the temperature about 20 F higher than the outside.

To fill the Pool we use tap water, that we run through the carbon filter to take out the .5 ppm of clorine and any other contamination.

The balance of the water stays in range all the time with no use of any of the chemicals promoted to handle the pool.

We did also a bacteria test and had no colony build in 48 h in the petry dish. We followed the instructions in the equipment manuals and had a great result.