Green water after baking soda and Shock

[Bruno Martins]

Hi guys, I'm new to the forum and pool caring.

Have the pool for a couple months and was taking care of it with dichlor only. And it was crystal clear.

But my pH was around 7 - 7.2 and last week I added sodium carbonate to raise the pH. The same night I shocked the pool.

The next day the water got cloudy, and remained like that for the next days. Now it is becoming greenish and cloudy and I don't know what to do. Chlorinating doesn't seems to be doing the job.

Though about shocking it again, use a FLOC, brush the pool and drain the bottom.

My pool is vinyl and my filter is a glass filtering element or something like that.

If someone could help me out here, cause I don't want to fill my pool with unneeded chemicals that the stores try to push us.

Thanks in advance for the help!!

 

[Texas Splash]

Welcome to TFP! The best resource for many of your pool questions is our Pool Care Basics page. Great articles. But to some of your points:
- Along with increasing the CYA too quickly, the dichlor may have been pulling your pH down. Stick to liquid chlorine if available.
- Baking soda can influence TA quicker that pH, but it will cause changes. As long as the pH is anywhere between 7.2-7.8 you are fine.
- Do not use floc. You'll cause more problems later.
- To kill and remove algae, you must follow the SLAM Process completely. That page will do the trick.
- The perform a SLAM Process, you must have a proper test kit. Either a TF-Series test kit or a Taylor K-2006C.

I would encourage y ou to post a full set of water test results for us first and confirm how you are testing. Then we can get more specific to assist you. Enjoy the forum.

 

[Texas Splash]

Also be sure to update your signature. See mine as an example and the article below. Your pool and equipment info helps a lot.

Create Your Signature - Further Reading

www.troublefreepool.com

 

[JamesW]

But my pH was around 7 - 7.2 and last week I added sodium carbonate to raise the pH. The same night I SLAMd the pool.

SLAM is not a one time thing.

You probably mean "Shocked" which is a one time addition of chlorine.

If you used calcium hypochlorite, then that would react with the sodium carbonate to produce the cloudiness as the calcium and carbonate combine into calcium carbonate.

The green is more likely to be iron than algae.

 

[Bruno Martins]

Welcome to TFP! The best resource for many of your pool questions is our Pool Care Basics page. Great articles. But to some of your points:
- Along with increasing the CYA too quickly, the dichlor may have been pulling your pH down. Stick to liquid chlorine if available.
- Baking soda can influence TA quicker that pH, but it will cause changes. As long as the pH is anywhere between 7.2-7.8 you are fine.
- Do not use floc. You'll cause more problems later.
- To kill and remove algae, you must follow the SLAM Process completely. That page will do the trick.
- The perform a SLAM Process, you must have a proper test kit. Either a TF-Series test kit or a Taylor K-2006C.

I would encourage y ou to post a full set of water test results for us first and confirm how you are testing. Then we can get more specific to assist you. Enjoy the forum.

I'm from Brazil and don't have such test kits, unfortunately.

I have been having some trouble, getting different reading by different test kits, drops and strips.

Tomorrow I will try and evaluate the parameters and will post it later here.

Also will post the parameters of my pool. Thank you!

 

[Bruno Martins]

SLAM is not a one time thing.

You probably mean "Shocked" which is a one time addition of chlorine.

If you used calcium hypochlorite, then that would react with the sodium carbonate to produce the cloudiness as the calcium and carbonate combine into calcium carbonate.

The green is more likely to be iron than algae.

James, you're right, I shocked the pool! How to correct this? This calcium carbonate in the pool and this green iron accumulation?

 

[Bruno Martins]

So, I did a couple of things.

My TA was around 10 so I added 1kg of baking soda, then I added 200ml of metal sequestrant (I don't know the name of it in English), and as nothing was happening, I tried FLOC.

Nothing happened to the water, its still milky green. Nothing seems to work.

I'm doing things terribly wrong but I don't know what.

The only thing I didn't try was algicide, but I'm scared of filling my pool with more chemicals.

 

[JJ_Tex]

Green is either caused by algae or iron, so I would think step 1 would be identifying why your pool is green.

For algae, we typically would recommend you do an OCLT to test and see how much chlorine you are losing overnight. That will be tricky without a test kit, but do you know your chlorine reading currently and when the last time you added chlorine?

In the US, iron staining is typically limited to water that comes from a well. Are you on well water or know if your water source contains iron? Many times if you have iron in your water you will see iron staining in bath tubs, sinks, toilets, etc. as well. Do you see any of that?

 

[Bruno Martins]

Green is either caused by algae or iron, so I would think step 1 would be identifying why your pool is green.

For algae, we typically would recommend you do an OCLT to test and see how much chlorine you are losing overnight. That will be tricky without a test kit, but do you know your chlorine reading currently and when the last time you added chlorine?

In the US, iron staining is typically limited to water that comes from a well. Are you on well water or know if your water source contains iron? Many times if you have iron in your water you will see iron staining in bath tubs, sinks, toilets, etc. as well. Do you see any of that?

Hi JJ, thanks for the help.

Yes, the water here leave stains all over the places.. take a look at the picture of this faucet with only 2 months of use.

 

[DavidLast]

Is the pool outdoors? Is it blue colour internally? Looking close at the water do you see small particles swirling around even when the pump is off for a while?

 

[JJ_Tex]

Hi JJ, thanks for the help.

Yes, the water here leave stains all over the places.. take a look at the picture of this faucet with only 2 months of use.

Hi Bruno - Those look like hard water spots. Do you notice any iron staining on the porcelain, usually where the water comes out of the faucet into the bowl of a sink or toilet and will look yellow or rusy over time? The below picture is a bit extreme, but something like this:

 

[Mdragger88]

Bruno,
A couple things.
#1 Do not run the floc through your filter - it will gum up your filter media.
You must let it settle & vacuum it to waste.
If it has gone through your filter be prepared to change out the media sooner rather than later. I assume this is a sand filter. Regular old pool filter sand #20 silica is fine.

Flocculant - Further Reading

www.google.com

The real #1:
You must have adequate fc for your cya level or you will get algae.

Once you get algae it takes the
SLAM Process to eradicate it. This is not a once or twice addition of chlorine.

As mentioned the dichlor adds cya (about 1ppm for every 1ppm of free chlorine it adds) the chlorine gets consumed daily but the cya doesn’t leave unless you replace the water.
Do you have any clue how much dichlor you have added to the pool since filling it?
Do you have access to somewhere that can accurately test your cya level?
If not you’re only guessing at whatever you put in & are unlikely to be able to clear this up if it is algae.
How are you getting the numbers you logged in poolmath?

#2 Metals (most likely iron) -
You can see if the polyfill method catches anything to help determine if the green is iron. Just add some polyfill to the skimmer basket. (Yes,The stuff thats in pillows & stuffed animals) you can use an old Tshirt or skimmer sock to keep it contained.

If you’ve got iron in your fill water, use Polyfill to remove it

You'd be a millionaire if you discovered something cost-effective to filter soluable iron pre-oxidization ;) I'm rooting for you! Even the greensand filters are only partially effective and are dependent on flow rate and concentration.

www.google.com

#3 STOP adding stuff
Do not add anything else except liquid chlorine (unadulterated bleach).
The dichlor is tanking your ph/ta, increasing your cya, & possibly has other additives (like copper).
No algaecides (doesn’t help active algae anyway & possibly contains copper) ,
NO MORE FLOC (causes more problems than it solves),
no sequesterants until you know what’s going on.
Please list the ingredients in the sequesterant you used.
You’ve went from a cloudy & low fc issue (that isn’t that complicated to clear up)
To a mess now with the floc.
You said the pool was crystal clear - why were you “shocking” in the first place?
Was fc below minimum for your supposed cya at that time? If so you likely have algae.
Even if you have a metals problem taking care of the algae comes first.