Just opened pool - shock with 0 CYA?

[doncaruana]

So, once again, my CYA disappeared over the winter. That's a separate discussion. And the pool company that opened I don't think actually put any "shock" in because a couple of hours after they left my FC was at 0.5 and my CC was at 6.5. However, my TA is 80, CH is 60, and pH is 7.4. All great numbers. (My salt is only about 2000, so I need to get some salt too, but not a big deal either).

That being said, I need to shock this thing obviously (it's pretty green). With no CYA, what level should I bring it up to? For SWG pools, the shock chart only goes down to 60 CYA.

On a side note, is it possible they *did* throw shock in (they had two bottles pool side, but I didn't see them put it in or exactly what it was) and it went down that low that quickly?

Thanks everyone!
Don

 

[jblizzle]

Dose to 10ppm now and repeat as often as every 30 minutes until the CC reduces and the FC starts to hold. Then add 30ppm of CYA and start to do a true SLAM. You have ammonia you want to remove before adding CYA.

Slam level is the same for SWG pools.

 

[JasonLion]

They must have added some chlorine. You won't get a CC reading unless chlorine has been added in the last several days.

I would start SLAMing the pool, and then work on adding CYA wile the SLAM is on-going. Instructions on SLAMing are in the How To section of Pool School.

 

[doncaruana]

Thanks guys. I couldn't find the SLAM article and forgot about it. I followed it religiously last year as part of my "education" process. Found it again (bookmarked it). Need to get a lot more bleach though

 

[songebob]

My one suggestion to this post is that while slamming and before you start adding CYA to vaccum and backwash the filter one last time because once you add CYA you should not be backwashing.

 

[doncaruana]

My one suggestion to this post is that while slamming and before you start adding CYA to vaccum and backwash the filter one last time because once you add CYA you should not be backwashing.

Thanks, but I've got cartridge filters. The bottom is a mess though, even though it was vacuumed yesterday.