New SWG and Water Balance


LifeTime Supporter
Apr 14, 2013
Good Evening all,

FC: 9ppm ( due to shock )
PH: 7.5
TA - 90
CYA - 110
Salt - 4000ppm
Borates 0 (until I put them in)

Question, Below are the specs stated for TA and CYA. What are the effects if I leave the CYA at 110 with the SWG? The TA I can adjust by lowering the PH and Aerating, but I don't want to dump more water. Well System can't handle that much water churn. Will I run into any issues?

TA 60-80
CYA 70-80



TFP Expert
LifeTime Supporter
Jan 6, 2010
San Dimas, CA (LA County)
It CAN be maintained with astronomical CYA, but it is not easy, nor would I recommend it. Your minimum FC is above the top of the OTO tester. So the color block quick test for FC is useless. The only way to test FC is the FAS-DPD test every day. And if you do get an algae bloom, you'll be buying bleach by the drum, not the gallon to kill it.

You can ease it down a little at a time so you don't overtax the well, or keep fingers crossed and ensure the FC is always above 5 and watch that CC. If it starts climbing, nip it in the bud!

As an aside, rainwater is CYA free, so if you're in some part of the country that actually sees rain in the summer months, divert a downspout into the pool. Maybe into a bucket that can act as a settling basin for the dust it washes in.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
One of the major problems with CYA levels over 100 is that you never really know what your CYA level actually is. The common CYA tests read any level over 100 as about 100, so your actual CYA level could be way higher than you think it is. Without a good idea of what your CYA level actually is there is no way to get your target FC level correct.
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