This is Howard Garret the Dirt Doctors take on spider mites. He is a proponent of organic gardening in Texas.
"Spider mite infestation is a clear sign that water is not effectively moving into the plant. The problem can be caused by too much or too little water, chemically imbalanced soil, compacted soil or other environmental issues. Liquid seaweed spray is highly effective to rid plants of spider mites, in fact it works as well or better than any of the toxic chemicals that are commonly recommended. However, the mites will re-infest unless the major problem that invited them in the first place is not corrected."
That is news to me, I had a real bad infestation once when I put an outdoor plant in with the indoor plants (I was new at it, what can I say. And it was back in 1980, before the internet). I tried pepper sprays with little effect using a cayenne mix. I have found Neem oil to be pretty good but I will be trying the liquid seaweed spray if I ever encounter mites again.