Water went cloudy overnight - help me understand.

[clean]

Hi Guys, new spa owner here. totally inexperienced, but good common sense with mechanical/chemistry etc.

So i've had water in our new spa for about 35 days now. things have been going fine/uneventful for the most part. I have been maintaining 1-3ppm FC with dichlor granules the entire time.

The drama started a couple nights ago after we got out of the tub, I failed to add the usual 1/2 cap or so of dichlor granules, and just went to bed (big mistake). the next morning I woke up to a cloudy tub. I immediately tested for FC and not really a surprise it was 0.

I don't have any chlorine shock, but gave it a good dose of dichlor, MPS oxidizer, and changed the filter in the hopes of killing whatever bloom took place, and filtering it out to get the water clear again (not sure if getting the water totally clear again is possible?)

I have a few questions on what took place, and how to proceed going forward.

1. when FC drops to zero and contaminants / heat are present what causes the cloudy water? is it a bloom of algae? or some sort of bacterial growth? Is it generally the same strain/species is most cases? what is it called?

2. I realize after 35 days of using dichlor my CYA level was probably getting high causing the chlorine to become more and more ineffective. I tried using bleach once which jacked my PH and scared me off doing that again.

I just used regular no additive bleach from the supermarket when I probably should have been using pool specific liquid chlorine, but I have been told it also cranks your PH?


It seems that your either going to run into having too much CYA if using dichlor steady, or if using strait liquid chlorine your going to have a PH problem?

What am I missing? thanks for any input.

 

[mknauss]

Welcome to the forum.
How are you testing your spa water chemistry?
If you have been using dichlor this entire time, your CYA is now sky high. Your chlorine is no longer effective.
Read the sticky at the top of this forum, How do I use Chlorine in my Spa (or pool)?

 

[Texas Splash]

As another suggestion, if you do find the CYA to be exceedingly high, a water exchnage will be required. Did you do an Ahh-Some purge when you purchased the tub? If not, that would be an ideal time to do a purge. Then re-balance everything from there.

Welcome!

 

[Gebo]

I agree with what’s been said. As far as the bleach question, I went to Rural Retreat and bought my liquid chlorine. It is 10% chlorine made just for pools. As far as I can tell, there is very little effect on my pH. I add an oz after using and less than 2 oz to shock every Monday (Along with my 1.75 oz of AquaClarity every Monday). I was scared I might not get the right grocery store bleach so I found the liquid chlorine.

 

[Mdragger88]

I have been maintaining 1-3ppm FC with dichlor granules the entire time.

This is the trouble right here- you have likely been under sanitizing for a while
& this episode was just the straw that broke the camel’s back. If you have a standard size 400 gal tub here’s what each 1/2 oz of dichlor does

You can see from the chart that only the lowest level of cya makes 1-3ppm fc acceptable - you were probably beyond that after the first 5 or 6 doses of dichlor (or less if your tub is smaller)

I tried using bleach once which jacked my PH and scared me off doing that again.

Once the liquid chlorine (bleach) is in the water there is no effect on ph.
It however doesn’t have the acidic effects that dichlor has so ph must be managed with acid.
As mentioned above its now time for an ahhsome purge, drain & refill. Then follow the guide @mknauss posted.
There’s really no sense in fighting with such a small amount of water- even if you do the SLAM Process with liquid chlorine & get it cleared up (which can take a while) you will still have an unmanageable tub due to the cya level.

 

[clean]

Welcome to the forum.
How are you testing your spa water chemistry?
If you have been using dichlor this entire time, your CYA is now sky high. Your chlorine is no longer effective.
Read the sticky at the top of this forum, How do I use Chlorine in my Spa (or pool)?

I am testing with the taylor 1004 kit. thanks for confirming my suspicions with dichlor and high CYA issue.

As another suggestion, if you do find the CYA to be exceedingly high, a water exchnage will be required. Did you do an Ahh-Some purge when you purchased the tub? If not, that would be an ideal time to do a purge. Then re-balance everything from there.

Welcome!

When I first brought the tub home I purged with ahhsome, and got a bunch of Crud out. I let the ahhsome run for about 45min, and even added some more until nothing more would come.

Being only 35 days later my gut said another purge wasn't necessary, but I did it anyway. To my surprise a hole Crud load more came out today, and oddly first it was brown sludge, then when that stopped I added a bit more ahhsome, then I started getting greenish sludge! anyway I purged the heck out of it.

I agree with what’s been said. As far as the bleach question, I went to Rural Retreat and bought my liquid chlorine. It is 10% chlorine made just for pools. As far as I can tell, there is very little effect on my pH. I add an oz after using and less than 2 oz to shock every Monday (Along with my 1.75 oz of AquaClarity every Monday). I was scared I might not get the right grocery store bleach so I found the liquid chlorine.

Thanks. I found that bleach cranked my PH, but if i understand correctly, is it just the first time you use liquid bleach that it causes the PH spike? after the first use then it has little effect on the PH? doesn't seem to make sense to me, but maybe that's the way it is?

This is the trouble right here- you have likely been under sanitizing for a while
& this episode was just the straw that broke the camel’s back. If you have a standard size 400 gal tub here’s what each 1/2 oz of dichlor does
View attachment 544031
You can see from the chart that only the lowest level of cya makes 1-3ppm fc acceptable - you were probably beyond that after the first 5 or 6 doses of dichlor (or less if your tub is smaller)
View attachment 544034

Once the liquid chlorine (bleach) is in the water there is no effect on ph.
It however doesn’t have the acidic effects that dichlor has so ph must be managed with acid.
As mentioned above its now time for an ahhsome purge, drain & refill. Then follow the guide @mknauss posted.
There’s really no sense in fighting with such a small amount of water- even if you do the SLAM Process with liquid chlorine & get it cleared up (which can take a while) you will still have an unmanageable tub due to the cya level.

Thanks, yeah according to that chart I was way under sanitized for awhile. So what do you mean " Once the liquid chlorine (bleach) is in the water there is no effect on ph" - do you mean that the initial dose of liquid chlorine will raise the PH, but after that it won't? I was under the impression that liquid chlorine had a PH of about 13. I found that when I dosed the tub with liquid bleach my PH went up a good bit - I don't understand how a substance with such a high PH wont cause an increase regardless of when/how it is introduced into the water?

The tub is now purged, and draining. So this time I will use dichlor until I reach 30ppm CYA, and then switch to pool grade liquid chlorine. to manage the PH increase the acid of choice is muriatic, correct?

 

[Mdragger88]

There should be no noticeable ph rise from the small addition of bleach if you allowed it to be mixed before testing.
If you’re testing ph then using the tub and then dosing with dichlor before testing ph again its likely that it rose but the acidic dichlor lowered it again. The bleach does not have this acidic effect so many are under the impression that the bleach is responsible for the ph rise when in fact ph would have risen if nothing were added.

PH - Further Reading

www.troublefreepool.com

The tub is now purged, and draining. So this time I will use dichlor until I reach 30ppm CYA, and then switch to pool grade liquid chlorine. to manage the PH increase the acid of choice is muriatic, correct?

You’ve got the right idea!
Use
PoolMath effects of adding to keep track of how much cya you’ve added.
Muriatic acid to lower ph is recommended.

 

[JoyfulNoise]

Your pH rise is related to the TA of your tub water and the aeration that comes from hot tub jets.

What would help is if you posted a full set of test results, with CH and CYA, so we can better advise you. The K-1004 is a fine kit for daily quick testing but you really need one of the better kits (TF-100 or K-2006) if you want to manage the tub properly. You need a CYA test and a CH test.