Discount Pool Supply

They are actually made by the same company so just get the one that feels the best

Call your local pool supply and ask them if they do a "new pool owner instruct". They should be able to come to your house and walk you trough all of your questions for about $95.00

If you are dealing with a protable spa and have issues with pH and the problem is that is always is low........Just Drain The Spa. Its just a big bath tub and should be drained 4 times per year. The real concern is the type of snitzer that you use and how it effects the water chemistry. If you use Bromine then you wont need to balance the pH. Bromine works better with a pH over 7.8 and will accomadte itself to new tap water just fine. Chlorine is the bigger issue. If you want to use a atomatic dispenser you are out of luck! Tablet chlorine has a pH of about 2.0 and the pH of the fiberglass of the spa is 7.0. Our bodies and the equipment require a slightly above neutral pH of 7.4. to 7.6 and a bit higher wont hurt either. The problem is, if you use a sanitizer that has a low pH and nothing to buffer it other than the TA of the water then you will need to buffer the pH yourself. Which means EVERY time you as chlorine you need to adjust the pH. And if the Total Alkalinity is allowed to be too high or too low for a period fo time then the pH will tend to drift the same direction. This is why it is easy to use Bromine and when the water does begin to age and a pH drift is noticeable because you need to adjust it weekly then just drain the spa and start over. Water is cheaper than equipment repairs due to corrosive pH.