High Cyanuric Acid- Rookie

[GNic59]

I'm new to TFP and after reading the forums have decided that Sam's Club Shock in bags and 3" pucks have created major issues with my CA this year. I guess I've been doubling the Stabilizer without knowing it. Just now learned I could get rid of these and utilize liquid chlorine like Clorox.
Current Readings- Pool store test today. Will purchase a nice tester soon.

FC 3.59
TC 3.74
CC .15
pH 8.1
TA 113 adjusted
Calcium 138
CA 147

I had turned off the Auto Chlorinator with 3" pucks last week, but then the Algae started to grow. Not bad just on deep end on walls. Brushed the floor & walls yesterday and I shocked with Liquid Clorox Bleach. Took the water sample this morning to Pool Store for reading. Algae has cleared up mostly this morning.

1) I know procedure is to pump out water to 1 ft above shallow end and replace to cut the CA down- are there any other options?
2) Is the algae a direct result of not having enough FC to get the algae?

Any other suggestions?

Thank you

 

[timerguy]

Assuming you meant cya --Ca is calcium. 1. Draining and refilling is the only option for reducing cya as much as you need to. 2. Likely! Mostly because of your high cya!

 

[jblizzle]

Welcome to TFP!!!

To expand a bit on the #2 response. Once the FC is allow to drop below the minimum FC level as a function of your CYA level, then algae can start. As the CYA level rises, the FC level required to prevent algae and disease also rises. See the FC/CYA Chart.

How much Pool School have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

 

[GNic59]

I thought Draining was the procedure I needed.
Is there a system that works best for draining water and replacing? My plan is to remove water via the Waste valve setting while running fresh water from hose at the top.
Is it better to drain water out first and then re-fill?
Thanks
GNic59

 

[jblizzle]

Yes you need to drain. How you best do that depends on your pool and setup. The waste is going to drain much faster than your hose is going to refill and only will work if you can isolate the floor drain.

You use the least water by draining and then refilling. But, the drain and fill at the same time can be a little safer in areas where there is high ground water levels or extreme heat.

 

[timerguy]

You have a vinyl pool so you need to leave at least a foot of water in the deep end--for me that was 8,000 gals X 5 to drop mine from around 350 to 50. Fortunately, i could turn off my skimmers and just use the floor drain. Unfortunately, I didn't do that and ended up replacing my polaris boost pump :-( Oh, and pool store cya testing is notoriously inaccurate. Your cya could be much higher.

 

[krazykrames]

You have a vinyl pool so you need to leave at least a foot of water in the deep end

Isn't it the shallow end?

Anyway you need one of the test kits recommended here to get an accurate reading of your CYA, otherwise you are going in somewhat blind.

 

[GNic59]

Thanks for the responses.

 

[timerguy]

Isn't it the shallow end?

Anyway you need one of the test kits recommended here to get an accurate reading of your CYA, otherwise you are going in somewhat blind.

OMG YES, the SHALLOW end I'm so sorry!

 

[GNic59]

My new Tester will be here today, so I will be able read my own.

Update: After draining pool to the 12" mark on the Shallow End of pool, I filled back up to normal and add 140 oz of liquid chlorine 8.25%. Pool looks great- clear.
After 24 hours had Pool Store test and results are:

FC 3.79
TC 3.79
pH 8.1
TA 89 adjusted
Calcium 115
CYA 115

I was able to cut the CYA about 30%, does this mean I need to drain again?
Should I wait for my tester to arrive and test myself?

Thanks for the advise.
GNic59

 

[jblizzle]

Since they are still saying the CYA is high, I would do another drain or two.