light green after the rain

Jun 3, 2008
9
0
NJ,USA
#1
Hello to all.
We had yesterday a lot of rain. In the morning water in the pool turn a litle cloudy and slightly green. What could be the problem?
Thanks for any reply.
 

frustratedpoolmom

LifeTime Supporter
TFP Expert
In The Industry
May 20, 2007
12,177
0
44
SWSuburban Chicago, IL
#2
HI there

It's hard to say, but it sounds like you don't have enough chlorine in your water, and you have developed algae.

I would recommend reading the articles in Pool School, if you have not done so.

Do you have a way to test your water? If so, run a complete set of results and post them on this thread. Also, update your "profile" to include your pool equipment/info. IT's helpful also to know what part of the world/country you are located, as weather conditions sometimes alter the advice (hot/full sun, etc.)

I also highly recommend your own good test kit, like the TF-100 test kit (link is on the home page) or the Taylor k2006.

Welcome to TFP. We're glad to help you clear your pool....
 
Jun 3, 2008
9
0
NJ,USA
#3
Thank you for your reply.
I have 20x40 free shape pool, it holds about 30000-35000 galons of water. I shocked yesterday with 3 bags ( 1 lbs each ) pool shock, and today in the morning I took water test, and rsolts as follow:

FC-10
CC-0
TC-MORE THEN 5 (Could not reed, the color dark yellow, bot not orange)
PH-7.5
ALK-120
CYA-100

After the shock and pump running about 5 hours water gets more clear, but not perfect yet.

Thanks again for any advice.
 

frustratedpoolmom

LifeTime Supporter
TFP Expert
In The Industry
May 20, 2007
12,177
0
44
SWSuburban Chicago, IL
#4
jacobichka said:
Thank you for your reply.
I have 20x40 free shape pool, it holds about 30000-35000 galons of water. I shocked yesterday with 3 bags ( 1 lbs each ) pool shock, and today in the morning I took water test, and rsolts as follow:

FC-10
CC-0
TC-MORE THEN 5 (Could not reed, the color dark yellow, bot not orange)
PH-7.5
ALK-120
CYA-100

After the shock and pump running about 5 hours water gets more clear, but not perfect yet.

Thanks again for any advice.
Your TC has to be at least 10 if your FC is 10....

Do you have an SWCG?

CYA is too high, if that number is accurate. Cloudy/dirty water can make the test false high readings.

Edit ~ If/when your water clears I would retest it to make sure that's correct.

You will fight a losing battle with algae repeatedly unless you lower your CYA. See the CYA chlorine chart for your level of CYA and the minimum and target amounts of FC and shock levels. IT takes ALOT of chlorine when CYA is that high.

Edit ~ if your CYA is really 100, the only way to lower it is to do a partial drain and refill with fresh water.

The recommended range for CYA is 30-50, unless you have a SWCG, then you can go 60-80.

The best thing you can do is shock with bleach, that way you are not adding any unnecessary chems that you frequently find in powdered or granular shock (di-chlor shock contains CYA-if your's is really 100 you DON'T want to add more CYA!)

Good luck....let us know if you have more q's.
 

JasonLion

LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
37,879
5
Silver Spring, MD
#5
The common CYA test will read 100 even when the CYA level is higher than 100. If CYA is actually 100 then a FC of 10 should have kept the algae away, but if CYA is actually higher you could easily not have enough chlorine in the pool.

By far the best thing to do is to replace some water to get your CYA level down below 100. Fighting algae with high CYA levels requires huge amounts of chlorine. If you catch it quickly enough you might be able to kill all the algae, but once it gets away from you it gets very difficult to clean up the pool with CYA that high.