Dad's Pool ... SLAM and what else?

[wyckoffpool]

Posting for my dad.. He is having an algae problem, so he probably needs to go through SLAM, but does he need to fix his TA/pH first?

FC: could not get a reading, I added 20 drops and the solution was still red.
pH: 6.8
CYA: 40
TA: 30

*****Please ignore the pool specs in my signature as those are for my pool. His pool is: 14k gallons, manually chlorinated, vinyl liner*****

 

[mknauss]

Add 30 ppm TA worth of baking soda.
What is the CYA? Looks like a trichlor pool and typically a sky high CYA.

 

[wyckoffpool]

How do I calculate what 30ppm is? I have the Pool Math app and I don't understand.

 

[mknauss]

With your test results entered, touch the TA on the Home Screen. A page will open that will have your Current TA and Target TA. Put 60 as your Target.

 

[JJ_Tex]

FC: could not get a reading, I added 20 drops and the solution was still red.

If you used 10ml sample size (which is recommended to save on reagents) 20 drops is a FC of 10. Most likely during a SLAM you will need to keep going to 30 or more drops to get an accurate FC reading.

 

[wyckoffpool]

With your test results entered, touch the TA on the Home Screen. A page will open that will have your Current TA and Target TA. Put 60 as your Target.

Why is 60 my target? The TF test kit says its 100-120 for manually chlorinated pools.

*****Please ignore the pool specs in my signature as those are for my pool. His pool is: 14k gallons, manually chlorinated, vinyl liner*****

 

[mknauss]

Adding baking soda should raise your TA and your pH will follow. The pH reading is not viable right now as your FC appears to be over 10 ppm.

Your target range for TA (vinyl pool) is 50-90 ppm. See What Are My Ideal Pool Levels?

 

[wyckoffpool]

After adding the baking soda, when should I retest? How long after

*****Please ignore the pool specs in my signature as those are for my pool. His pool is: 14k gallons, manually chlorinated, vinyl liner*****

 

[mknauss]

If you need to SLAM, add the baking soda and move on to the SLAM. Test the TA tomorrow.
What is the CYA?

 

[wyckoffpool]

If you need to SLAM, add the baking soda and move on to the SLAM. Test the TA tomorrow.
What is the CYA?

CYA is 40.

 

[mknauss]

Great. Odd that the TA got so low.
Happy SLAM'ing.

 

[Bperry]

Why is 60 my target? The TF test kit says its 100-120 for manually chlorinated pools.

*****Please ignore the pool specs in my signature as those are for my pool. His pool is: 14k gallons, manually chlorinated, vinyl liner*****

100-120 is if you are solely using trichlor for chlorination.

 

[wyckoffpool]

100-120 is if you are solely using trichlor for chlorination.

Yes, it does look like he uses tricolor tablets for chlorination.... so my TA should be higher as noted in the test kit instructions.

 

[wyckoffpool]

Question on SLAM... in the articles here it says to evaluate the CYA/FC relationship.. so when I input my CYA level (40), the output tells me that my "SLAM level is 16".

What exactly does this mean? This should be my chlorine drop test result?

*****Please ignore the pool specs in my signature as those are for my pool. Dad's pool is: 14k gallons, manually chlorinated, vinyl liner*****

 

[wyckoffpool]

This is my SLAM FC level, I think I got it.

 

[Bperry]

This is my SLAM FC level, I think I got it.

Yes, that’s only for SLAM. Normal FC in that CYA level is 3-7ppm. But don’t let it actually get to 3ppm.

 

[Bperry]

Yes, it does look like he uses tricolor tablets for chlorination.... so my TA should be higher as noted in the test kit instructions.

Not really. Your TA is safe down to 50ppm or so. But trichlor is an acid which will lower the pH and the TA somewhat, so you have to watch it and make sure it doesn’t go that low. But higher TA will push the pH upward faster so it’s a balance.