Just bought Tf100 kit and I am new to all this!

[Emiller]

First off I want to say thanks in advance. I just bought a house with a pool so I am new to everything. Here are my readings from my kit. I am using 3" chlorine tablets. My pool has been open for a week now. I took these tests before running my filter for the day. My filter has been off for about 12 hours. Will the results change after running my filter for say 4-5 hours?

Ph is 7.5
FC is 5
Cc is 0
Ta is 170
Cya over 100 ( did test twice).

Looks to me my cya is really high and at the point I should drain and add water. Any help or suggestions would be greatly appreciated!

 

[jblizzle]

Welcome to TFP!!!

You should always run the pump at least 30 minutes before testing and after adding any chemicals.

You are another victim of the dreaded trichlor tablets. You CYA is just way too high to be a manageable and now you need to replace a lot of water. Do the CYA test starting with half pool and half tap water, then reagent, then test outside in indirect light with the tube at your waist, pout the mixture back and forth a few times to see what you get, then double the reading. That will give you a better idea how much water needs to be replaced.

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

 

[Isaac-1]

What Jason said, sorry

Ike

 

[Richard320]

Welcome!

What does the pool look like? Is it clear?

You should do another CYA test using the dilution method in Post 8, step 9 here Then you'll know how much water needs to be replaced.

If the water is clear, you can replace it to lower CYA in stages. You have the Cadillac of test kits, so maintaining adequate FC for high CYA is feasible, just a massive PITA. But a drain down to get to, say 80, and then a week later, say 50 might be a better idea. You never want to empty a vinyl-lined pool below a foot anyway (What type of pool do you have? It helps to fill out your signature)

If the pool is green, ignore that last paragraph.

 

[Emiller]

Thanks for the responses so far. I have a 21' above ground. I retested using the half pool water and half tap water and I got a reading of 70. My water is really clear.

 

[Richard320]

Thanks for the responses so far. I have a 21' above ground. I retested using the half pool water and half tap water and I got a reading of 70. My water is really clear.

If 50-50 showed 70, your CYA ia about 140.

To keep it clear, you should keep your FC above 11 at all times, and target maybe 15 when you dose every day. Your overall chlorine consumption won't be much worse, it will just be at a higher FC level. The problem is, the pH tester gets weird and reads falsely high when FC is above 10.

It's your call; maintain it at the higher CYA level and pray for rain to dilute it and hope you don't develop any algae because clearing it at that level is next to impossible; Drain out 2/3 in one shot and proceed from there; or do it in stages, maybe 25% at a time, using the water on the lawn once a week until CYA goes down to something reasonable. You know your situation better than I do: do you have room to dump that much water or are you on a well?

 

[Emiller]

One last question. Does everything else look ok other then raising my FC till my cya drops?

 

[jblizzle]

Yes. But, you need to replace water to lower the CYA which will result in the pH and TA and CH all changing as well.

Replace the water and then retest everything.