Swimming Pool Blog

Hot Water Chemistry: Spa Chemical Care

Pool Cover Pump Care & Maintenance
by Mark Garcia December 06, 2013

Spa and Hot Tub Chemical Care

Do you want to smile as big as this spa user? It may be me, but I'm sure she's smiling at how clean and fresh the spa water is - undoubtedly a result of balanced spa water!

How to achieve perfect spa water balance, easily and consistently? I've got a system of my own, that has served me well for a number of years, and I'm proud to say that I've never had an algae outbreak, nor have any of my friends and family reported a strange rash!

5 Steps to Perfect Spa Water Chemistry

1. Check Spa pH and Bromine 3x per Week

I use a dropper style test kit, it's more accurate than test strips. But doing it with frequency (and making necessary adjustments) is the most important thing. If your spa testing and adjustment is consistent, you'll find your pH (and alkalinity) to be more stable and consistent as well. I check my spa chemistry before I use it, and after I use it (I'm keeping a log), and it's amazing the changes that I see when 3 or 4 people get out of my hot tub.

Be sure to also measure your Total Alkalinity regularly too. If your pH is erratic and hard to control, or hard to adjust, or resistant to change, it's likely that your alkalinity is too high or too low.

2. Drain the Spa Every 3 Months

I set myself a calendar reminder in Outlook. I don't look forward to it, it's a few hours of my weekend that I could be watching football - but it's important to be consistent (there's that word again), and drain your spa or hot tub on schedule. 3 month intervals is what I use, but you may need it every 2 months, or every 4 months, depending on how several factors.

The main factor in your spa drain schedule is how often you use the spa. Consider other factors too, like how many spa users you have on a regular basis, (1-2 people, or is it 2-3?). The condition of your spa filter cartridge also palys a role, and of course water balance matters too. A spa with these other factors or issues should probably drain every 2 months.

3. Use Minerals and/or Ozone

I use both. Nature2 spa stick, and I have a Del ozonator. It's a recurring expense, which I'm not a fan of - but the combination of the two - ozone+minerals, does so much of the bacteria fight, that my bromine and filter only have to work 1/3 as hard as they would have to if I just used bromine alone. And, my spa only needs about 1/3 of the bromine that it would normally need. I still shock regularly, and keep a pH around 7.5, which rounds out and kind of summarizes my entire hot water chemistry routine.

4. Shower before Spa Use

Honestly, consider how 'clean' your users (and you) usually are. We all use the spa at times without showering, covered in sweat, dirt, skin and hair products, and this places a huge demand on the filter and sanitizer. My wife and I try to make it part of our spa routine. I almost always take a quick shower before, and head out to the spa in my robe. What I need is an outdoor shower, next to my spa. That would be convenient, I may build one!

5. Shock After Spa Use

It takes just a few minutes after you get out of the spa, and has also become part of my spa session. When I get out of the spa, I always test the water first, to see if I need to lower the pH before shocking. Plus as mentioned, I keep a spa chemical log, because I'm actually studying and analyzing my spa chemistry over time. Geeky, I know - but I'm in the business you know.

Your spa pH should be no higher than 7.6, so if it looks high, first use some spa pH down before adding the spa shock. A lower pH will make your spa shock much more powerful and active.

After shocking, I keep the spa cover open for an hour or so, to let it gas off and allow my spa cover to 'breathe' for a bit longer.

5 Steps to Perfect Spa Water:

5 steps to perfect spa water

That's what works for me! Hot water chemistry is a bit different from pool chemistry, but is no more difficult to understand and control. Just be consistent in a few things - like showering, testing pH, shocking and draining - and also replace your spa filter cartridge every year or two, and your spa water should never give you any trouble. And if it does, drain it, and do something differently!



Thanks for Reading;
Mark Garcia