May 30, 2013 - 02:14 PM
Typically, when you mix any pesticide with tap water, the minerals, etc, start to break down the pesticide immediately. The water is only the carrier. In other words, the water allows you to apply a very small dosage of pesticide to the area you are spraying and then it evaporates. After the water evaporates, it leaves a chemical film that will kill insects when they crawl over it.
Generally, most water based insecticides that you add "tap water" to, will only last a few days in the spray tank before they begin to separate, break down, etc. I would highly recommend to use whatever you have and then rinse the bottle out.
Retail products that are water based and "ready to use" are made from what is called "deionized water". It is pure water stripped of everything including ions, minerals, etc. This water will allow the pesticide to last much longer in suspension.
The best way to get rid of most pesticides is to simply use them. Spray the foundation, of your home, spray along the fence, spray the yard. If nothing else, take the top off of the bottle and just pour it along the foundation.
Never pour pesticides down the drain, sink or toilet. This is against the law and will pollute our sewers and ultimately end up in lakes, etc. Just use it up. Also, never mix more than you need. You could break the Pestabs in half or quarters and put the rest in a plastic bag to save for future use.