#38 -Swimming Pool Chemistry and the "Gotcha's"
You remember: the stuff the salesman left out but that you learned later.
All of life has gotchas, and
swimming pools aren't exempt. But, the best time to learn about "gotcha's" is
before they get you. So, we've made a list for swimming pool owners.
All the normal maxims apply here:
- Look before you leap.
- Read the label.
- Follow instructions.
- If a little is good, a lot may not be better. [Hint: this one is real
important for pools!]
Don't misunderstand: we use many of the products and methods below. But, we
watch out for the gotchas when we do.
Here are a few pool gotchas:
- Softswim and Bacquacil don't work well with filters: the active chemical,
PHMB, gums up filters. This can be fatal (to your filter) with DE or cartridge
filters, and often requires annual sand replacement on sand filters.
- DPD testing for chlorine (the white pills that turn pink if chlorine is
present) breaks down when chlorine is high: at chlorine levels above 15 ppm, it will bleach out
and remain clear. Every year, hundreds of pools and especially, spas, end up
with chlorine levels of 30, 40, even 100 ppm -- enough to leave with you with
an itch that want quit.
- Overdosing with SuperBlue or similar clarifiers can result in haze that will
not filter out for days.
- High stabilizer levels can make it difficult or impossible to control
algae. "High" seems to be anything above 60 or 70 ppm.
(Actually, it can make it easier, too -- this needs to be updated. Ben - Mar
2011)
- The so-called oxygen shocks, based on DuPont's Oxone (potassium
monopersulfate) apparently change chloramines to nitrates -- algae fertilizer
-- instead of nitrogen gas. Worse, some of the other oxy-shocks (ones not
using monopersulfate) can actually REMOVE the chlorine from your pool. And,
one widely sold type (also, not monopersulfate) has been associated with
severe skin irritations among swimmers.
- Adding calcium increaser (calcium chloride) and alkalinity increaser
(sodium bicarbonate) is a recipe for a BIG mess: an extremely milky looking
pool, that is slow to clean up.
- UV based ozone systems, which inject large amounts of air with small amounts
of ozone, can result in plaster damage.
- ALL forms of acids react DANGEROUSLY with all forms of chlorine or
bromine. Never, never, NEVER mix swimming pool chemicals of any type!
