Crystal clear water turns black after adding chemicals, Help!

What is floc, clarifier, stabilizer, cyanuric acid,
algaecide, brightener, dichlor, sodium hypo,
sodium bisulfate, ....??
Pool Newbie
Pool Newbie
Posts: 1
Joined: Wed 28 Jun, 2017 20:09
My Pool: 24' Round, 48" tall above ground

Crystal clear water turns black after adding chemicals, Help!

Postby Kady » Wed 28 Jun, 2017 20:22

After replacing the liner, trucking in 12,000 gallons and filling the last 1500 gallons with the hose, I brought the water to get tested at the local pool store. Water was crystal clear. The levels were as follows:

Free Chlorine: .06
Chlorine: .09
Stabilizer: 0
PH: 7.5
Alkalinity: 33
Calcium: 14
Iron: 0.1
Copper: 0
(they left the phosphates line blank)

The pool store told me to add 15lbs of Alkalinity Balance, 2 hours later to add Calcium Balance, and then at night to add 1.5 gallon shock, a bottle of algeacide concentrate, and a bottle of pool enzyme.

Followed all their instructions. Right after the final step, the pool water turned black... What went wrong?

Swimming Pool Superstar
Swimming Pool Superstar
Posts: 997
Joined: Tue 06 Sep, 2011 05:48
My Pool: 10k inground fibreglass, Telescopic Cover, Hayward Powerline pump, Quality filter with glass media, 27kw output heat pump, K-2006C test kit
Location: United Kingdom

Re: Crystal clear water turns black after adding chemicals, Help!

Postby Denniswiseman » Thu 29 Jun, 2017 03:28

I'm not in a position to explain what went wrong but you've been pool stored
It may settle down
Get yourself a decent test kit (Taylor K2006C or TF100) and test your self
You are in an ideal position to keep your pool spotless with fresh water
You can get most of the pool store chemicals from your local store
Liquid chlorine (sodium hypochlorite or plain bleach)
Muriatic acid (hydrochloric acid) to lower pH and TA
Bicarbonate of soda to raise TA
Aeration will raise pH only
You need to get some stabilisor and chlorine in there ASAP with relation to Pool Levels and Chlorine / CYA Chart
to prevent an algae bloom
Be carefull of algaecides as a lot of them contain copper causing more problems
CH is not a problem with a liner only a plastered pool
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm
Check out these links
Pool School
Pool Maths

Return to “Pool Chemical Problems & Swimming Pool Chemicals”

Who is online at the Pool Help Forum

Users browsing this forum: CommonCrawl [Bot] and 2 guests