Guam pool care: thanks for all the help!


Apr 2, 2019
Thanks in a large part to all of the helpful articles and forum threads on this site, I have enjoyed taking care of my own pool for almost a year and a half now. I just thought I would post a little location specific information, which could be helpful to others getting started in Guam, with some lessons learned that may apply in other remote areas too.

Bottom line:
For me, it works best to alternate between using trichlor tablets, and cal hypo granules due to local costs and long shipping times for liquid chlorine. Whenever CYA levels get high with tablets I switch to granules, and would only switch to liquid if calcium levels get too high with the granules. I also use the granules when a SLAM is needed, and so far have had enough dilution due to rain to keep both the CYA and calcium levels under control without liquid for a full year now.

Guam specific details:
Guam's average annual rainfall is 98" (2489.2mm), and the daily high temperature is around 88 degrees (31C) year round. Pool temperature is usually around 88 degrees as well, though after a few days of overcast weather and heavy rain I have seen it dip as low as 80.

Some good news is that does ship here with reasonable rates, so I have been able to get the recommended test kit, refills and some accessories from the site.

We do have a Home Depot here which carries liquid chlorine, trichlor tablets and some basic pool supplies. Unfortunately the liquid is several months old by the time it reaches the shelf, so the effective concentration is considerably reduced (labeled 10%, but tests closer to 5-6%). We also have a pool store on island (Tropical Pool Service), which provides service and sells parts and chemicals, and another distributor (Total Chemical Resources) also brings in granules and tablets.

Due to the low concentration in the liquid chlorine, and the high price of $4.65 per gallon, I have found that trichlor tablets are the cheapest way to raise FC here ($2.20 per lb). The next cheapest option is cal hypo granules when purchased in 100 pound buckets, which is still cheaper than liquid chlorine, even after the price increased recently by 30% due to stricter shipping requirements. To reach these conclusions I created a spreadsheet comparing cost per FC increase for each of the locally available options.

Thanks again for all the help, and I hope this post returns the favor for others.



Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
Fletcher, OK
Wow, Great information for people in Guam... TFP is all about taking control of your pool and knowing what's going into it... Nicely done figuring all this out and making it work for your situation :)


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
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