Cloudy Water and greenish tint(algae)

[bcorrie]

I have a 20x40 rectangular gunite pool approx 30000 gallons with
Chlorine:9
Combined Chlorine:0
PH: 7.2
Alkalinity:190
Calcium:220
Stablizer:30

I use a taylor K-2006 kit to test the water. I read some of ChemGeek's posts and have intentionally kept PH low at 7.2 .
I have backwashed the filter and the pump has been running for about 36 hrs now but no improvement - the water is still cloudy with a bluish green tint.

I also have a problem with air bubbles in the return line. I have checked the skimmers and ensured all fittings are air tight. But I have been unable to locate their source. Anyone have any thoughts as to where the leak is?

I use an opaque (blue) solar blanket during the day to reduce evaporation and Chlorine dissipation but now I wonder if that is
aggravating the algae situation.


Your assistance is appreciated


Green Newbie

 

[frustratedpoolmom]

Welcome to TFP!

I take you recently shocked your pool (the FC of 9)?

It takes time to clear algae. Recent threads on here have shown it is taking some about a week of proper shocking, brushing, backwashing, etc. for the water to clear.

As for the air bubbles, have you checked every possible source? The pump basket, the pump pressure release valve, etc.?

You have come to the right place, there are many folk on here who will be able to help.

 

[DMS]

Hi,

I am a first-time pool owner as well. I just went through a similar experience with a slight green tint in my water.
I shocked and kept chlorine levels high for a couple of days. The water turns a little milky white and it took me about 10 days (24/7) of filter/backwash to clear out the milky white.

I think my original problem was letting chlorine levels drop while the solar blanket was on...be careful.

Has anyone else had to clear the milky white water? Would they recommend any of the products out there.

DMS

/* 16X32 rectangluar IG, viynl liner, 1HP pump, sand filter */
/* current test CYA 40, FC 4.0, TA 120, ph 7.6 */

 

[reindeerboy]

I did try a product called Pool first aid. It was pretty cheap at intheswim.com.

Normally I never use anything like this, but had a huge amount of Green Algae this spring upon opening the pool and to aid in getting ride of the dead algae, I decided to try this enzyme additive.

In 4 days it helped eat away the dead algae & Pollen in the pool and now it is fantastic.

I only use bleach/liquid chlorine now as my CYA is adequate so that keeps the algae completely at bay. I have found that about a chlorine level of 4-5 is about right according to the table located in here with the level of CYA that I have.

 

[bcorrie]

UPDATE 1
=======

The pool is clearing up, however I cannot see the bottom at the deep end yet.
FC:7
CC:0
PH:7.3
TA:90
CA:215
CYA:20~30

I went to the pool store and got my water tested. The pool store uses an electronic water analysis system. Their tests indicated
FC:6, CC:0, PH:7.9, TA:70,CA:120,CYA:10

The calcium and PH levels are way off now I do not know which test results are valid.

I use a Taylor K-2006 Kit I bought last year. Does anyone know what is the shelf life of the kit?

What is target CYA level for a 30000G gunite pool?

Thanks for your help

 

[frustratedpoolmom]

30-50 is your target, the higher end if you are in a particularly sunny area. I wouldn't trust the pool stores results, your K2006 results should be fine, and the reagents should be still good, assuming it was stored in a normal place, not like a hot garage or shed...

With that high FC and little to no CYA, your PH test is probably a false high reading. Keep an eye on your numbers keeping your pool covered. You should let it "breath" so to speak, others are reporting algae outbreaks with frequent solar cover use. I use mine all the time with no problems but every pool is different.

Your Calcium should be 200-400 ppm. Pool stores tests can be inaccurate. I would always trust my own results before theirs.

 

[JasonLion]

I would trust the Taylor kit test results over the pool store. CYA 30-50 as frustratedpoolmom said.

FC levels of below 10 don't interfere with the Taylor PH test, so no issue there. Though longer term, raising the pH a little is probably a good idea because adding CYA is going to lower it.

(frustratedpoolmom: the PH test rules are a little different during a baquacil conversion because of the temporary PH change from adding bleach before it gets used up.)

 

[frustratedpoolmom]

I would trust the Taylor kit test results over the pool store. CYA 30-50 as frustratedpoolmom said.

FC levels of below 10 don't interfere with the Taylor PH test, so no issue there. Though longer term, raising the pH a little is probably a good idea because adding CYA is going to lower it.

(frustratedpoolmom: the PH test rules are a little different during a baquacil conversion because of the temporary PH change from adding bleach before it gets used up.)

So it's only during a baq conversion that PH will read false high from shocking?

 

[JasonLion]

This is getting technical, nearly enough to move to The Deep End.

There is always a risk of the pH reading wrong at high FC levels, but how high the FC level is before you worry about it varies a little depending on the situation. Normally if FC is below 10 the PH test will be fine, and between 10 and 15 it will read just a little high. If FC is above 15, don't trust the PH results.

During a baquacil conversion, or other times when the FC level is well above "normal" because of adding bleach, the PH results should be ignored above a FC level of about 5-8 above "normal" because of the temporary PH shift from having just added bleach.

In this particular case the FC level is 6 or 7, which is both below 10 and less than 5 above "normal", so the Taylor PH test results are valid.

 

[frustratedpoolmom]

This is getting technical, nearly enough to move to The Deep End.

There is always a risk of the pH reading wrong at high FC levels, but how high the FC level is before you worry about it varies a little depending on the situation. Normally if FC is below 10 the PH test will be fine, and between 10 and 15 it will read just a little high. If FC is above 15, don't trust the PH results.

During a baquacil conversion, or other times when the FC level is well above "normal" because of adding bleach, the PH results should be ignored above a FC level of about 5-8 above "normal" because of the temporary PH shift from having just added bleach.

In this particular case the FC level is 6 or 7, which is both below 10 and less than 5 above "normal", so the Taylor PH test results are valid.

Got it, and thanks for the clarification. I'd hate to give out bad advice.... :bowdown:

 

[bcorrie]

hi all,

Its been two weeks and I still cannot get this to clear.

Heres what I have 30,000 gallons , gunite.

been keeping it at 8ppm FC for the last two weeks and at 14 FC for the last 3 days. The pool appears to be eating about 3-4 ppm/day. First had cloudy water so I used floc and the water cleared but its still bluish green. I have been brushing every day but cant seem to get to clear blue. Any thoughts?


FC: 14
CC:0
PH:7.4
TA:190
CYA:25
CA:220


Thanx

 

[chem geek]

The 8 ppm FC with 30 ppm CYA for the last two weeks was probably not enough to get significantly ahead of algae growth, especially when it dropped lower after getting partially used up fighting the algae. The recommended shock level at 30 ppm CYA is 14 ppm FC that you are now at, but since it's been taking so long I'd suggest you raise the FC to 18 ppm and hold it there. Continue the brushing and running the pump 24/7.

As for your opaque solar cover, it will help reduce FC loss from sunlight and somewhat slow down algae growth (if it's really opaque), but will prevent some outgassing of products from the chlorine fighting the algae. A tough call. You could try having the cover off one day and raising the FC level higher, say to 22 ppm, in the morning and see if that makes any difference.

It sounds like your pool is in-ground. Does it have floor drains and are they working?

Richard

 

[Butterfly]

Hi bcorrie,

It would be very helpful if you would add all your pool and equipment information in your signature. You can do that by going to the top of the page, left side under TFP logo, and select User Control Panel. Select "profile" and then "edit signature".

Welcome to the forum :-D

 

[bcorrie]

Chemgeek,

Thanks for the suggestions I shall try them today. And yes it is an inground pool with one bottom drain that is not working
- do you think that this is part of the problem? I have tried augmenting circulation with another pump that sucks water from the bottom.

I use a blue opaque solar cover and though it saves chlorine I wonder if is aids the algae.

I shall report back with the results

 

[frustratedpoolmom]

Usually with solar covers, if they are contributing to the problem, you will see CC's show up in your test results. Normal cover use shouldn't cause algae, I use mine all the time and I don't have any algae issues.

I suspect you haven't had your chlorine levels high enough and long to be effective. Is your 14 FC constant? Meaning you are adding bleach up to every half hour? Has your 14 FC been tested thru the "overnight" testing process, and has it held? Fighting algae and having it clear quickly, the best route is to raise it to shock level and hold it there till the water clears up. So if you've been shocking to 14, say, in the evening, and then letting it drift back down each day, then raising it again....during the day the algae is just still active at the lower levels of chlorine. The FC has to be at 14 and STAY there for 24 hours to several days depending on how bad the algae is.

Circulation certainly could be part of the problem. No way to get the bottom drain working? Augmenting with another pump might do the trick, are you still doing that?

 

[bcorrie]

I went out this evening and I could not believe the bottom is finally visible! The yellow hordes have become lil piles of dust. Mebbe tomorrow we will be able to use the pool.

Thanx ChemGeek , raising the level to 18 FC worked. I think frustratedpoolmom had a point in that even though I had FC at 14, it prolly never held as I did not check till the next morning. Good point, frustratedpoolmom I will remember that for the next time.

Thanx All