Cloudy Pool after adding 55lbs Baking Soda/Sodium Bicarbonate

[melgiov23]

Problem:

Noob here, need some help. I was trying to fix a 37.5m3/37.500L (10.000 gallon) pool with 4.5 pH, low alkalinity, and low chlorine level. I Added about 25kg (55lbs) of baking soda (sodium bicarbonate) into the pool over the course of 2 nights with the filter being set on "circulate" mode for around 12 hours each day.

On the third day the pH stabilized around 7.2, the water was very blue, however very cloudy. I added two 8cm (3 inches) TCCA/Trichlor (Trichloroisocyanuric acid/Trichloro-s-triazinetrione) Tablets onto the pool and hoping the chlorine level would go up and clear the water for another 2 days with setting the filter on "filter" mode" (running around 12 hours each day).

On the fifth day the water was still very cloudy with negligible difference even after leaving the pool filter running for 24 hours. The chlorine level is also still low (just slightly better when compared to beginning).

My questions:

1. The water was very cloudy with whitish powder residue floating around the pool, especially when I tried to brush the pool floor, these powders came up floating to the surface (Images attached). What could this be?

- Is it from the sodium bicarbonate not yet fully dissolving into the water? or could it be something else? maybe precipitated calcium carbonate because of sudden change of pH from 4.5 to 7.2?

- What is the best way to fix the problem since the filter seems to be not doing a very good job clearing it? Should I use flocculant? I can get PAC (Poly Aluminium Chloride) to use as flocculant, is it safe to use while having baking soda and TCCA/Trichlor in the pool?

2. Why is the chlorine level going up very slowly after 2 days? could it be because of the slow dissolving TCCA/Trichlor tablets? need Should I add more?
Or should I shock/super chlorinate instead? But I have read somewhere that it's dangerous to mix/at the same time use Bleach/Sodium Hypochlorinate (inorganic) with TCCA/Trichlor/Trichloroisocyanuric acid/Trichloro-s-triazinetrione (organic).

Any answer/help is greatly appreciated, Thanks!

FC: 0.5ppm
TC: 1ppm
pH: 7.2 pH
TA: 60ppm
CH: Can only read total hardness at around 500ppm
CYA: 30ppm
TDS 800ppm

My pool: 37.5m3/37.500L (10.000 gallon) In-ground, concrete surface with tiles
Pool chemicals: Food Grade Baking Soda (Sodium Bicarbonate), TCCA /Trichlor (Trichloroisocyanuric acid/Trichloro-s-triazinetrione) 8cm/3inch tablets
My pump & filter: Hayward Max-Flo 1HP pump with Hayward Vari-Flo XL Valve Filter (SP0714T1)
Other info: 28 degree Celsius / 82.4 degree Fahrenheit pool temperature

Images:

https://ibb.co/XyWtVHk
https://ibb.co/nbFBzK9

[Teapot1]

You should never add that much bicarb in one go, it can take several days to dissolve and increase the TA. You cannot buy waiting in a pool shop but that is what you are going to have to do. Wait, take things a bit slower.
It is dangerous to mix any acid with a chlorine compound as it will release chlorine gas.

[melgiov23]

Teapot1, Thanks for your response.

I've consulted the local pool shop today and they said, to speed things up/clear the pool faster, should put more TCCA/Trichlor but in glanural form (so it dissolves faster in water and raise the chlorine level faster), and after getting the chlorine level to the minimum of 3ppm, they advise to flock it for 24 hours to get rid of the powder (with the filter on "circulate mode"), and then vacuum to waste until clear. Do you think this is a good idea? or should I just wait another 3 days to see if things improve?

[Teapot1]

No i dont. The fine powder is your as yet undisolved bicarb. Boosting the chlorine is just that and not needed unless you require shocking.

[melgiov23]

Teapot, thanks again for your answer. It has been 2 weeks now and seems there's no much progress even after running the pump and filter 12+ hours daily. Pool is still cloudy even when chemicals have been in balance since last week (correct level of Alkalinity, pH, chlorine, CA, etc.). Does the bicarb really take this long to dissolve or there is another problem? two days ago I tried adding some clarifier and changed the sand in the sand filter, also made sure that there is no other problem with the filter (leak etc.), but both didn't make any significant difference. Right now the TDS is 650 ppm. Also I've just found out previously the pool maintenance guy used copper sulfate every two weeks to clear the pool and there were light blue stains around the pool edges since I added the bicarb, could it be some chemical reactions? What do you reckon I should do try to do next? Maybe flock it? Your response appreciated, Thanks.

Current Pool Condition: https://ibb.co/1d6krh1

[Teapot1]

The excess after the water has absorbed as much as it can will often precipitate also depends on the water hardness.
Copper drops out of solution at pH8.2 and raising the alkalinity quickly can create a high pH on the pool walls as the bicarb combines with the surface to create a hard surface (good) from calcium hydroxide. Lowering the pH will usually cause the copper to change back to the more soluable form but not always. From this you can see copper and copper algaecides and ionisers should never be used in plaster, tiled etc pools.

[melgiov23]

Hey Teapot, I guess you were right. What makes the pool cloudy not only the undissolved bicarb and also years of chemicals residue from previous maintenance that reacted to the high pH. In the end I decided that I couldn't wait any longer and flocked the pool, and now I have crystal clear pool after a lot of waiting and cleaning .

To recap what I did:

- Made sure chemical levels were right
- Replaced the sand in my sand filter with zeolite
- Backwash and rinse filter 3x
- Put in clarifier
- Ran the pump and filter in "filter" mode for 48 hours
- Backwash and rinse filter
- Put in flocculant
- Ran the pump and filter in "circulate" mode for 3 hours
- Turned the pump off and waited for 48+ hours
- vacuum the gunks on pool floor to "waste" mode
- Put in clarifier
- Ran the pump and filter in "filter" mode for 48 hours
- Backwash and rinse filter
- Ran the pump and filter in "filter" mode

I hope this information can help others with similar problems.

Current Pool Condition: https://ibb.co/FsC9YYv

[Teapot1]

Glad its sorted.