slamming - added recommended bleach, got low FC increase

[ChewBiscuit]

OK I just opened my pool to a green swap and so reading the pool school and attempting to slam it.

I punched these numbers into pool math:

24300 gallons
0 FC -> 29 FC
ph 7.0
Ta 70
Ch 150
CYA 75

It recommended a shock level of 29 and to get to that from 0, 1063 oz of 8.25 bleach. I added, tested after half hour with pump running and got 12 FC. Waited another half hour thinking maybe it just hadnt mixed all the way, got 11.5. Both times I got 1 CC.

I added the bleach by pouring over the deep end returns and am using the TF-100 test kit.

Any thoughts on what I should do? Did I add too much at once? Could my bleach (all new bottles of Crystal brand) be bad?

Thank you in advance for any suggestions.

 

[JohnT]

Odds are, with a green pool the algae is consuming the chlorine almost as fast as you add it.

Add what it takes to get to shock level, then test and add more an hour later as needed. Repeat until there is little drop in the hour between tests, then go to four hour intervals.

 

[Divin Dave]

Yup. what JohnT said. Keep maintaining the FC and backwash when you need to.

 

[Richard320]

Don't forget to brush to expose the algae on the walls and get the bleach mixed up good.

 

[ChewBiscuit]

Ok, thanks. I will keep after it.

I was rereading the testing instructions and just realized I wasn't doing the CC test correctly, so that 1 CC number was completely wrong.

 

[ChewBiscuit]

Just did my last test for tonight. Had given one last brushing a little earlier.

FC: 30.5
CC: still 1 after doing the test the right way

So, a few things are confusing to me. I added that chlorine up to shock level a couple hours ago and since then i show almost no loss, does that seem too soon? Also shouldn't the CC be much higher if its killing bacteria and algae? Just wondering how I could have gotten these results which to me look like little activity; would it be worth double checking my CYA?

Plus as I'm typing i can hear it starting to rain outside; how does rain normally affect the slamming process and test results?

Thanks again for your help.

 

[scott.MI]

Just want to throw out there that you could consider using a 5ml water sample where each drop = 1 instead of .5. Doing 60 drops has got to be a drain.

 

[duraleigh]

Rain has little affect on Pool Water Chemistry. Many don't believe that but it is generally a true statement.

Diluting your accuracy to 1.0 ppm with the 5 ml sample is okay but the more newbies "trick up" these tests, the more confused they usually get.

The biggest issue with Chewbiscuit's pool is the CYA of 75 which calls for the FC to be so high. A drain/refill to get CYA down to 40 would lower his SLAM value to 16 ppm and save FC the rest of the swim season.

 

[ChewBiscuit]

Rain has little affect on Pool Water Chemistry. Many don't believe that but it is generally a true statement.

Diluting your accuracy to 1.0 ppm with the 5 ml sample is okay but the more newbies "trick up" these tests, the more confused they usually get.

The biggest issue with Chewbiscuit's pool is the CYA of 75 which calls for the FC to be so high. A drain/refill to get CYA down to 40 would lower his SLAM value to 16 ppm and save FC the rest of the swim season.

I looked some draining posts. So do I just run the hose and keep back washing to replace water? Is there a time interval where I can stop and recheck my CYA? (1 hrs, 4 hrs)

 

[Richard320]

I looked some draining posts. So do I just run the hose and keep back washing to replace water? Is there a time interval where I can stop and recheck my CYA? (1 hrs, 4 hrs)

Use the "waste" setting on your multiport valve to drain. It bypasses the sand completely. Pool > pump> waste line.

When I drain and refill to lower CH, I just check it a day later after it's had plenty of time to mix. I know I'll lose the same percentage of CYA.

 

[rick6668]

When I drain and refill to lower CH, I just check it a day later after it's had plenty of time to mix. I know I'll lose the same percentage of CYA.

Wow what a great idea. Seeing as the CYA test in the TF-100 uses quite a bit of R-0013, this is a great way to get a good estimate without wasting R-0013. I always have plenty of reagent for the calcium tests.

 

[ChewBiscuit]

I just vacuumed a little bit ago and I have a bad feeling I have a ton of **** in the bottom of my deep end. But I can't see it to aim my net/ brush/vacuum at it. When I was vacuuming it, a bunch of **** kicked up like leaves and dead earth worms. Then the water got super cloudy and my returns were blasting dirty water for a few seconds back in.

I'm concerned about not being able to see what's down there and that its hampering my efforts. What do i do?

On the plus my water is now blue with a slight green tint over the deep end instead of bright green after one day slamming. Im just worried the crud down below is going to prevent me from getting it done all the way.

 

[JVTrain]

Gotta get that sludge out of there. It's only going to eat up your $$$ on bleach. Sweat equity time. Get in there with a leaf rake and get you as much as you can, even if it's blindly. Rake til you can't rake no more (either due to being tired or no more stuff, preferably the latter). Then vacuum, with a leaf bag is preferred if you have one.