Tips to Control Spider Mites

1. Take a look at the product you are spraying.  Generally miticides only kill adults and nymphs not the eggs, these are called adulticides. Spraying leaves eggs to hatch in a few days.  This makes it seem that new mites have arrived when in truth they were there all along, just as protected eggs.  By doing consecutive sprays 5 to 7 days apart, you will kill newly emerging mites. 
2. Another option is to spray a product that is an ovicide. Ovicides kill eggs, so after sprayed be prepared to still see adults alive on the plants along with eggs, but the eggs will not hatch.  There are products that have adulticides and ovicide properties, this gives them a real 1…2 punch.
3. Many pesticides are pH dependant.  This mean they need to be at the right pH to work efficaciously. Water that is higher then a pH of 7 can create alkaline conditions, causing pesticides to break down quickly. So when spray they become in effective.  This problem can be correct by knowing the Ph of the spray water. If higher the pH of 7 reduce the ph to a range of 4 to 7.  This can be done by using a buffering or acidifying product such as Phase-5 (Indicate-5).  Reading product labels will usually give optimum pH or talk to your chemical supplier.