Question about slamming pool

[pv5490]

Hello everybody!

Last week my pool's FAC dropped to 0.5ppm, so it got cloudy. We tried to fix it with a small shock, but now the pool has turned completely green and looks awful.

pH 7.3
FAC 6.0
CAC 0.5
Alk 80
CH 160
CYA 80

It is a 500,000 gallons public pool. As a source of chlorine we use calcium hypochlorite and trichlor. I used Copper Sulfate yesterday but it did not work (It didn't stain, plus, the concrete in the pool is already very damaged)
I want to slamm it tonight. According to my calculations, I need 190lb of calcium hypochlorite (I know it's better not to use that because it can make it cloudy, but I only have trichlor and calcium hypochlorite. Buying something else is not an option, unfortunately) to take it to 30ppm of FAC. Then maintain it there until there is less than 1.0ppm of FAC overnight loss, the pool is clear and CAC is less that 0.5ppm.

Is that correct? Will it work?

Also, I am not sure whether I should slamm the pool today. The pool looks awful, but I'm not sure if it's unsafe for athletes to swimm in 30ppm of FAC, even if the CYA is 80ppm. Unfortunately, closing the pool for a few days is not an option either (I tried once and it was a huge mess).

Should I slam it or wait until the weekend comes? Taking the risk it will get even greener and cloudier than it already is.

Thank you for your help!

 

[mrcarcrazy]

What are you using to test? I'll let others answer the actual chem questions...but this will be helpful to them.

 

[jblizzle]

If it is a public pool, are you sure that you are not required to close it down?

You understand the SLAM process, but we do not typically recommend swimming above shock level.

Your CYA is already very high and thus you should not use trichlor anymore. And you are right that adding all the cal-hypo could very well make the water cloudy by itself.

How do you test? Remember the pH test is not valid when FC > 10ppm.

 

[pv5490]

Hey! I use the K2006 Taylor kit Complete FAS-DPD.

Actually, I am required NOT to close down the pool. It's a huge problem if I close it. I know it make no sense, but that is hpw thing work out here.

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Also, since the trichlor is slow release, it messes up my overnight loss test. Since it stays releasing chlorine for a long time after adding it. Another reason why I don't want to use trichlor. :S

 

[jblizzle]

So I imagine the facility says you can not close it?
But, I bet the health department (or some government entity) has more say and can shut you down if it gets reported ....

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So, you have to remove the trichlor to do the OCLT ... but you can not use it anyway since your CYA is too high. You are quickly approaching having to drain the pool to keep it clear.

Any reason you can not switch to a SWG or chlorine gas system? besides the cost I imagine.

 

[pv5490]

Haha believe it or not is a government owned pool (hence the difficulty to get appropriate chemicals). Btw I'm not in the US.
Anyways, last time something like this happened congressmen and a lot of "influential people" complained to the place I work with because the pool was closed for a couple of days.

I know this makes no sense, it doesn't make sense to me either.

 

[jblizzle]

IF you are not in the US, then why does your profile say Florida?

Please add your location (City, State or City, Country) to your profile and pool details to your signature as described HERE as it will help us help you in the future.

 

[pv5490]

Yeah. It is mainly the cost. I will look into it, though. Do you think it can do a better job keeping the pool clear?