Drain and Refill...what next?

[rukruk]

So I drained my pool, as my CH was ~700 and my CYA was ~90. I definately don't want to repeat the same mistakes and since I'm starting with a pool of fresh new water, I would love some help on what to do next!

I want to shock my pool as well, as there is some algae I would like to remove...should I shock without raising my CYA? seems liek I'd need less chlorine..

~15k gallon SWG pool

Reading from the new water -
FC - .5
CC - 2.5
pH 8.0~8.2
T/A 80
CH ~130
CYA 0!

Looks like the first step would be to get some stabilizer and, and see where that puts me after a week or so?

Also the pool calculator only has a calculation for FC...do I ignore the level of CC? Or do I put in the TC in that box to see whats needed?

will add some acid to lower the pH, and get the chlorine up to needed levels...at least until I get the CYA to the point I want it?

Thanks for the help!

 

[Butterfly]

First, lower pH to about 7.2.

Second, shock level for zero CYA is about 10PPM FC. Use bleach/liquid chlorine to maintain shock level per directions in Pool School.

Third, add enough CYA to get to about 30, using the sock method in front of a return.

Leave SWG off until you are done shocking. See red lines in my sig.

Ignore the CC level when using the PoolCalculator.

What happened with the black algae in the other post? Is that what you see? Describe the algae for us.

What type pool do you have? plaster, vinyl or FG?

It would be helpful if you added your pool and equipment specs in your sig. Go to "User Control Panel" top left under TFP logo, select Profile, then Edit Sig.

 

[rukruk]

The pool has a pebble floor...

Yea definitely black algae, slimey top, scraped off and is green when wiped on the concrete. While we drained I scrubbed off what we could, but couldn't remove the algae entirely, so hoping the shock can kill of any we missed....shows up on the steps (add a tablet directly on this?), and in the corners of the pool.

So I got some liquid stabilizer just, pool school says to not have a zero level CYA when shocking...so a bit confused...should I add stabilizer ~30 and adjust the target chlorine level accordingly? Or try to shock with 0 CYA?

I'll add my pool to my sig, very much appreciate the help!!!

 

[duraleigh]

Shock your pool with about CYA 30ppm. This gives you a degree of protection from losing ALL your Chlorine to the sun.

 

[jblizzle]

Adjust up to 30ppm CYA and shock based on that level. Otherwise the sun will consume the FC quickly.

Need to get your pH in range before you start shocking though.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[anonapersona]

I suggest investing in a very small stainless steel brush. You will need to brush really hard to get those algae spots out, a small brush lets you apply more force.

 

[duraleigh]

I am in complete agreement with anonapersona's very good post....get the brush....you'll need it.

 

[rukruk]

So I cleaned my filter (super overdue), I'm guessing after the shock, ill need to clean it again?

I also added the acid to lower my ph, next ill add to up my CYA (got some liquid conditioner). Should in insure both ph and CYA are good before adding chlorine?

 

[Butterfly]

So I cleaned my filter (super overdue), I'm guessing after the shock, ill need to clean it again?
You should clean the filter every time the psi rises about 20% over clean pressure psi.
I also added the acid to lower my ph, next ill add to up my CYA (got some liquid conditioner). Should in insure both ph and CYA are good before adding chlorine?
Okay, you got the pH down. Now add the liquid conditioner, wait 30 minutes with pump running, and then add bleach/liquid chlorine to shock level.

 

[anonapersona]

I will offer some more advice.... we did cure the black algae in my friend's pool. We shocked at mustard algae level for a day while the CYA level was at 30, then let the FC level lower and Bill got into the pool to pick at the spots in the pool with a knife, although the replaster was only 3 years old it was pitted and BA inhabited each pit in the shallow ends and corners. I do not recommend this, it is tricky to know exactly what shock level is since CYA levels are hard to read exactly, Bill was sensitive at nose and lips after that. Then we went back to mustard algae levels. We set a trichlor tablet on spots for about 20 minutes then scrubbed as hard as possible, moving the tablet to the next spot. Hard work! We did win and I hear that with the CYA corrected and pool returns repositioned for better circulation regarding the prevailing winds, the pool is fine now.

 

[rukruk]

thanks everyone for the help, the pool has been pretty sparkling since I did the drain and refill / shock. Glad I scrubbed the algae while the pool was drained as it is much harder to do with it filled back up for the spots that were not completely removed :grrrr:

 

[jblizzle]

So does that mean you still see algae? If so, are you still holding at shock levels?