SPA, SWG, CYA question

presse55

0
Bronze Supporter
Aug 8, 2016
39
Montreal, Quebec, Canada
Hello group!

What a great site this is! I acquired my first spa a few weeks ago and am very impressed at the quality information I found on this site. I am confident I'll be able to better manage my spa with the expertise found here!

In a nutshell: I have a SPA with a SWG and the pH is unmanageable - always runs high (>8).

I've read elsewhere that this is a common issue with SPA/SWG. I have also carefully read this post on why high CYA is a good thing with SWG and SPAs in particular.

My details:
  • 350 gallons (1300 liters); T=95F; 2 bathers every odd day;
  • The spa is covered when not in use; so affected minimally by sunlight;
  • TA: 110 ppm
  • pH: 8.1
  • CH: 110
  • Salt: 800 ppm (ideal 600ppm)
    I know this is low compared to most units currently being sold;
    The manufacturer no longer exists; this is what I found on their old website;
    It does use a Hayward T-Cell-5;
    The only function on the control unit is a timer which turns on/off 6 times a day for a duration I can set;
    I did clean the cell 10 days ago; and I can measure chlorine being produced;
  • TC = 1.5 - 2.0; FC = 1.5 - 2.0;
  • CYA: 0
  • Borates: 0

I would like to implement CYA & Borates.

I've been using a dry acid to lower pH but will switch to liquid muriatic acid.

My plan is to lower TA to 70 or so, which I am in the process of doing right now.

I use test strips for the time being, and plan to get a Taylor kit in short order.

Questions:
  • Am I ok in setting TA to 70 as a first step?
  • Then I will lower pH to 7.5 or so, is that Ok?
  • What should I do first: Borates or CYA?
  • I would target CYA of 50ppm or so, and/or Borate of 50 ppm; that okay?
  • Will the calculator on this site suggest proper quantities in my situation?
  • Should I do only one of these two, and monitor for some time (days/weeks) before going ahead with the second?

Any other suggestions will be greatly appreciated!

René
Montreal
 
Last edited:
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.