balancing before closure with my first TF-100 kit & results

[icycle]

Been keeping this pool clear for years using only 12.5% LC and occasional Borax but always get algae in the summer because I wasn't regularly adding chlorine. A couple weeks ago the water got really cloudy, I've since cleared it up by raising the Ph (Borax) and being more dilligent about chlorine... but it convinced me to get a real test kit and see where I was with balance. In short, I've been doing it wrong Anyway, I want to settle it before closing it, hopefully this weekend.

Numbers from 1st test with my new TF-100 a couple days ago:
FC, CC, TC: 0 (!)
TA: 50
CH: 30
CYA: 0
pH: 7.7

Last night I brought the chlorine up to 9 or so with the simple test, this morning it was 1.

Time to go to the store. Looks like I need:
CYA/stabilizer (not sure how much...but enough to bring it up to 30-40?)
more chlorine
calcium chloride for CH
baking soda for TA

Then time to SLAM.

Thanks in advance for confirmation/redirection on the plan above!

PS ... Also been reading on this forum about hooking up the variable speed peristaltic pump I got a couple years ago to automate the LC addition.

 

[jblizzle]

Re: balancing before closure with my first TF-100 kit & resu

Welcome to TFP!!!

Glad you have seen the light
You did not report your pH.

I agree you should add around 30ppm of CYA to the water. With no CYA, you will loose the FC to the sun very quickly and it makes the chlorine much more harsh to you and the pool.

Maybe dose the TA up to around 70ppm with baking soda, but I would not go much higher.
Ignore the CH, does not matter for a vinyl pool.
And of course you need more chlorine.

Get the CYA dissolving in a sock hung in front of the return jet. Get the pH in the lower 7s and then SLAM until you pass the 3 criteria to stop. Then you will be ready to start the closing procedure once the water is below 60 degrees.

 

[icycle]

Re: balancing before closure with my first TF-100 kit & resu

Thanks, I edited and added my pH measurement (~7.7), sorry about that.

Any idea how much solid CYA to sock up, to avoid waiting multiple weeks to measure the effective level? There's probably directions on the container, but just in case.

 

[jblizzle]

Re: balancing before closure with my first TF-100 kit & resu

You need to learn to use the poolcalculator ... check the link in my signature. Set the volume at the top and then set the starting CYA level (0) and the target of 30 and it will tell you how many OZ you need to add. Then add that amount and assume you will hit something close to your target and then confirm the CYA a week after it dissolves.

 

[icycle]

Re: balancing before closure with my first TF-100 kit & resu

You need to learn to use the poolcalculator ... check the link in my signature. Set the volume at the top and then set the starting CYA level (0) and the target of 30 and it will tell you how many OZ you need to add. Then add that amount and assume you will hit something close to your target and then confirm the CYA a week after it dissolves.

Ah, had not seen that before. Great resource, thanks again.

 

[icycle]

Re: balancing before closure with my first TF-100 kit & resu

56 oz of CYA is now in a sock hanging in front of the outlet, pump running continuously. Will wait to add anything else except chlorine until the readings come back.

thanks again

 

[jblizzle]

Re: balancing before closure with my first TF-100 kit & resu

You could bump the TA a little now as well if you like.
Then SLAM away once the CYA starts dissolving (give the sock a few squeezes every so often to help it dissolve).

 

[icycle]

Re: balancing before closure with my first TF-100 kit & resu

OK, a week after doing the additions of CYA and baking soda and a successful SLAM (ended 2 days ago) we now have readings:

FC = 6.5
CC = 0
TC: 6.5
TA: 70
CYA: 45-50
pH: 7.2 - 7.3

I'm planning to boost the chlorine to 12 and then close it. Thanks again!

 

[jblizzle]

Re: balancing before closure with my first TF-100 kit & resu

SLAM level is up around 18ppm for your CYA, so you could go that high and close it if the water is under 60 degrees.