Algae growth and cloudy

[allenwpax]

Hi Guys,

I just moved into a house with 30,000 gallon cement pool with DE filter. I got a simple test kit for PH and Chlorine. The PH measured very high, 1 gallon of acid later the PH range is good, verified by a test at Leslie Pool shop (1.5 hour drive round trip). They ran a water test and it showed phosphates were at 1700. So they sold me a Leslie product NOPHOS. Also got a floating chlorinator, put qty 5 of 3" tablets in it and set the holes for 30,000 gallon. I added 1 liter of the NOPHOS and later my DE filter pressure was getting high so i backflushed it, added new DE and then added another liter of the NOPHOS.

Now two days later my free chlorine level according to my simple test looks like ~5PPM yet I have algae trying to get started, I could see some small green patches on the bottom and when I brushed the pool I could see some green coming off the bottom and the water looked cloudy. I wonder if the NOPHOS chemical could be causing a false high test result for chlorine? I was getting inputs from other pool owners that I probably need two floating chlorinators but the test kit results say otherwise.

I would like to get more of the detailed tests from the Leslie pool store but the 1.5 hour trip makes that hard. I appreciate any help and guidance I can get.

Thanks,
Allen

[Denniswiseman]

Seeing as a round trip is to large. You really need to invest in a decent FAS/DPD test kit (Taylor K2006c or TF Testkits TF100 in the states) to get accurate results as maintaining an appropiate shock level means testing quite often during the day
Test strips are commonly called guess strips
You really need to Slam (Shock Level and Maintain) with relation to Chlorine / CYA Chart and Recommended Pool Levels
Excessive CYA renders your chlorine ineffective and you have to use more to get the same sanitation
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
To reduce your CYA you have to do a partial drain and refill
Continous use of Trichlor/Dichlor will raise your CYA which means you have to raise your chlorine level as well
Use these common products to balance your pool
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
Soda ash will raise pH and TA
Let's have your numbers
FC:
TC:
pH:
TA:
CH:
CYA:

[Teapot]

Listen to Dennis, he speaks the truth!

[allenwpax]

Guys,

I ordered the Taylor 2006 kit you recommended. Delivery will be next week.

Thanks for your help,
Allen

[allenwpax]

Guys,

Results are in:

FC 3.5 ppm
TC 4.25 ppm
PH 7.6
TA 100 ppm
CH 210 ppm
CYA 60 ppm

If I am using the Taylor wheel correctly the saturation index is close to zero.

The pool water looks clear now. It had been trending better day by day over the last week. Then yesterday I saw algae starting to grow again and I checked my floating chlorinator (duck) and saw there were only a couple of tablets left in it. So I filled it up to 5 tablets. I think my pool is telling me I need to keep the duck full of pucks to maintain status quo. Also I have some stubborn algae that is not being killed off by my maintenance level of chlorine and probably still have high phosphate levels.

The test kit booklet indicated a level of 30ppm for killing green algae but said nothing about how long you should maintain those levels or what it would take for other algae types. Any directions for the best way to do that would be appreciated.

Thanks,
Allen

[Denniswiseman]

Get rid of those pucks and get some Liquid chlorine (sodium hypochlorite or plain bleach)

Excessive CYA renders your chlorine ineffective and you have to use more to get the same sanitation
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
To reduce your CYA you have to do a partial drain and refill
Continous use of Trichlor/Dichlor will raise your CYA which means you have to raise your chlorine level as well

You need to Slam (Shock Level and Maintain) with relation to Chlorine / CYA Chart and Recommended Pool Levels

You need to continue to and pass overnight chlorine loss test (OCLT) Keep brushing, backwashing and look for the spaces that the algae can hide

[allenwpax]

Dennis,

I followed the links and I see what you are saying, the pucks I got are Trichlor and says it is stabilized so that would be the CYA.

From the Chlorine/CYA chart I should be targeting 7-9 ppm FC with 60 ppm CYA level. The first test kit I got said not to get in the pool with more than 5 ppm chlorine and the target range was 1 to 4 ppm, misleading info there.

Seems like it would take daily testing to stay in the target Chlorine range using liquid chlorine instead of the pucks. If I get rid of the pucks will the CYA ever dissipate without needing to do a partial drain and refill?

Thanks,
Allen

[Denniswiseman]

That's correct, but 7-9 is your target level not your slam level of 24
The info that is out about pools is old and misleading but isn't necessary true
You need daily testing if not more when slamming for your shock level
Once you have your algae under control and pass the OCLT you can start with a regime of testing at 9 and see how long it takes to reduce to your minimum of 5
The CYA will dissipate over time but splashout, leaks and backwashing will also reduce it

[GreatAussiePoolBook]

Listen to Dennis, he speaks the truth!

I agree with Teapot and Dennis
the initial conversation lacked the pH

Yes, pH was said to be FINE, yet no
measurement was observed.

warm regards.

[GreatAussiePoolBook]

Dennis,

I followed the links and I see what you are saying, the pucks I got are Trichlor and says it is stabilized so that would be the CYA.

From the Chlorine/CYA chart I should be targeting 7-9 ppm FC with 60 ppm CYA level. The first test kit I got said not to get in the pool with more than 5 ppm chlorine and the target range was 1 to 4 ppm, misleading info there.

Seems like it would take daily testing to stay in the target Chlorine range using liquid chlorine instead of the pucks. If I get rid of the pucks will the CYA ever dissipate without needing to do a partial drain and refill?

Thanks,
Allen

A lot of what you are saying here is reasonable. The missing piece of information it the pH.
All of these products INTER-relate in an environment we call "Water Balance"
the harmonious relationship of the waters requirements
Once you have that, you no longer have the battle with the chemicals needed
to achieve what it is you wish to do with the water, in this case
swimming
.

[Denniswiseman]

He has his pH here after getting his test kit and it doesn't look to bad

Guys,

Results are in:
FC 3.5 ppm
TC 4.25 ppm
PH 7.6
TA 100 ppm
CH 210 ppm
CYA 60 ppm

If I am using the Taylor wheel correctly the saturation index is close to zero.

The pool water looks clear now. It had been trending better day by day over the last week. Then yesterday I saw algae starting to grow again and I checked my floating chlorinator (duck) and saw there were only a couple of tablets left in it. So I filled it up to 5 tablets. I think my pool is telling me I need to keep the duck full of pucks to maintain status quo. Also I have some stubborn algae that is not being killed off by my maintenance level of chlorine and probably still have high phosphate levels.

The test kit booklet indicated a level of 30ppm for killing green algae but said nothing about how long you should maintain those levels or what it would take for other algae types. Any directions for the best way to do that would be appreciated.

Thanks,
Allen