50,000 Gallon Monkey On My Back

[mwsmith2]

You need more borax! Quick! Keep slapping in a box at a time until you see the pH move. Give about 4 hours of circulation time to get it evenly distributed.

Also, your math does not make sense. FC + CC = TC. You simply can not have FC = 13 and TC = 5. I think what is happening here is that you are getting the FC & CC from the DPD-FAS test, and then you are testing for TC again with the OTO test, which is topped out by your high FC level. If you use the DPD-FAS, you don't need to use the OTO test.

Since you are showing CC of 0, there's no need to keep the shock up for that purpose. When the algae goes from green to brown/gone you can let up on the bleach.

As for how much bleach to use, well, you use enough to keep your pool algae-free. Take a look here: http://www.poolforum.com/pf2/showthread.php?t=365 for the table to help you with this. For your CYA levels, it looks to be about 8 PPM.

There are 2 primary reasons to shock:

1. Algae
2. CC of 1+

Of course there are other reasons, (dead critters in the pool, fecal matter, etc) but those are the main ones. If you don't have a problem with the above, save your money and don't shock. I haven't shocked in close to a year now.

Michael

[duraleigh]

Hi, Korinian,

So, what to do next? Switch to bleach. If your water tests for no CC again, download mwsmith's calculator and bring your FC up to around 10ppm.

Have you loaded Michaels calculator yet? It's right above this post and will answer the majority of your questions about quantities. I'll bet your pH was W-A-A-A-Y low!!

Dave S.

[korinian]

Everything seems to be working. The dead algae is collecting on the bottom of the pool and I'll vacuum to waste. I was getting the TC number from the DPD-FAS test. I didn't realize it was redundant if you combined the FC + CC. Sorry about the confusion. I've downloaded and installed the beachcalc program.

I've dumped 3 more boxes of borax in the pool and the pH hasn't even twitched. Apparently, my pH was ridiculously low. I'll continue to pour borax in and keep the chlorine up. Thanks for all the help.

[mwsmith2]

Yeah, keep up with slugging the borax in there. Your pH got shoved way low by using those tablets. 50K/gal is a lot of water to get to move the pH. It will move, but it might take a while. Using bleach will also help pull your pH up. So, in the future you will be trying to keep your ph down rather than up. Luckily, that's easy to do with muriatic acid.

Michael

[korinian]

I'm now officially a bleach convert. Just thought I'd post my numbers throughout the opening of the pool. The pool is sparkling clean now. I don't know if this will help anyone else with a big pool or not. Thanks again to everyone for their help in this conversion.

I only had enough stuff to test CYA once. CYA was 100 on 4/15/06. I'm waiting on the new kit.

4/14/06 PM FC-0 CC-0 TC-0 pH-?? Alk-?? Took pool cover off. Added 5 lbs. of dy-chlor II and loaded skimmers with 3' tabs.

4/15/06 PM FC-3 CC-0 TC-3 pH-6.8 Alk-40 CYA-100 Added 4 gallons of bleach. 1 box borax.

4/16/06 PM FC-13 CC-0 TC-13 pH-6.8 Alk-50 Added 1 box borax.

4/17/06 AM FC-10 CC-0 TC-10 pH-6.8 Alk-50 Added 2 gallon bleach. 1 box borax.

4/17/06 PM FC-11 CC-0 TC-11 pH-6.8 Alk-50 Swept to waste. Added 1 gallon bleach. 2 boxes borax.

4/18/06 AM FC-12 CC-0 TC-12 pH-7 Alk-40

4/18/06 PM FC-12 CC-0 TC-12 pH-7 Alk-40 Added 2 gallons bleach. 1 box borax.

4/19/06 AM FC-12 CC-0 TC-12 pH-7.2 Alk-30

4/19/06 PM FC-14 CC-0 TC-12 pH-7.2 Alk-30 Added 2 boxes borax. 2 boxes baking soda.

4/19/06 PM2 FC-14 CC-0 TC-14 pH-7.2 Alk-100 Swept to waste.

4/20/06 AM FC-14 CC-0 TC-14 pH-7.4 Alk-100


Times:
AM - 7:00am
PM - 4:30pm
PM2 - 7:00pm

Boxes are = 4lbs.

THANKS AGAIN!!!

[MarkC]

How big was your box of baking soda. I'm very surprised you went from 30 to 100 with only two boxes of baking soda in such a big pool. Mine usually takes 15 pounds on startup.

[korinian]

They are 4lbs boxes. I was surprised also. I don't know if all the other chemical "magic" impacts the Alk level or not.

[mwsmith2]

Borax will raise your alk too, but to a lesser degree. Alk also tracks along with pH. So, as your pH rises, so does your alk. Good work though!

Michael