pH testing mistakes?

[duraleigh]

Not worried about the FC level.

I don't understand how with 600 posts and seven years on this forum you can say that.

FC is and always will be the primary parameter that determines the health of your pool. Yours is far too low. You are inviting algae and bacteria to come live with you.

Can you tell us your CYA level?

 

[crackers8199]

Since when are we not to use a “between“ number for pH?

I’m not sure how my physical testing could be off. I mean, it’s one of the easiest tests ImO. And same way I’ve done it for past years. But any ideas?

Previous years have shown the pH to rarely need adjusting. That’s why I’m so puzzled. Our sweet spot for personal preference is 7.8 and never had issue with keeping it between 7.6 and 7.8 before this year. Now it won’t hold and it goes up quick.

Having said that, I’m pretty sure I figured out the reason for recent large variances from day to day - old bottle of R-0004. Expired 6/2017. <OOPS!> First test this morning showed 7.6. To be sure, I tested it again, but shook the bottle up first (I usually shake all of them. Not sure why I didn’t this time). Sure enough, test came back at 7.9. Third test also showed 7.9.

And just tested again being sure NOT to shake bottle and though not as significant (bottle had only sat for 12 hours) got 7.4. Shook and tested again and got 7.6 (I added 2 cups of MA this morning, so that’s about right).

Now, does the old affect the accuracy when a bottle IS shook? Maybe. I’ll know more after I get a fresh bottle.

Not worried about the FC level. Pool does fine and I’m not going to get caught up on numbers. (Touché?) but because it can’t hurt to keep the FC up for reasons of figuring the ph out, I’ll overcompensate for it and keep it right. (Added 2 gal of 10% this morning. Current read is 3.5. Target is 5. Adding another gallon.

Thanks all for chiming in! I appreciate your time.
No matter the case, I’ll report back after a few days with the new bottle of R-0004.

are we supposed to shake the bottles before dropping each time? have i been testing wrong this whole time?

 

[mgtfp]

Current read is 3.5. Target is 5.

Going by your earlier post, the latest CYA measurement was 40. That means your FC target range is 5-7. The target range doesn't mean that you raise FC up to any value in that range and let it come from there to the min FC level. Your aim should be to keep FC at all times in the target range - the min FC is more of a lowest ever limit for unforeseen circumstances. It is like an airbag that you want to have, but never actually want to see in your whole life. If your daily loss was 2ppm, then you could raise FC to 7 and top up when it reaches 5 after 24 hours. If your daily loss was higher, then I'd rather go above 7ppm when adding bleach, than risking to get below 5ppm. If you have extra bather loads, I can make sense to add a bit of extra bleach.

3.5ppm is awfully close to the min. One more swimmer with a weak bladder on that day and you're below. And the logs you have posted show that there were times with 0 FC - probably because something went wrong. But aiming to keep your FC in the target range at all times, gives you more room for things going pear shaped without getting below min FC.

 

[Household6]

I don't understand how with 600 posts and seven years on this forum you can say that.

FC is and always will be the primary parameter that determines the health of your pool. Yours is far too low. You are inviting algae and bacteria to come live with you.

Can you tell us your CYA level?

I understand your confusion as my statement was misleading.

I’m not concerned about my FC AT THIS TIME - it’s the ph I’m trying to figure out why it won’t stay down.

I’m bad about not testing daily and not adding LC daily/every other day. Since getting the bot this year I’ve been even worse as it keeps the water free of debris for me (not that we ever had a lot) and I’m no longer a slave to the vacuum twice a week.

Long story short, it’s hard to convince myself to mess with water that APPEARS clear. But I know that’s not the proper frame of mind, and as you said I’m leaving the door open for the nastiest.
I will improve my efforts!

CYA is 40.

 

[Household6]

are we supposed to shake the bottles before dropping each time? have i been testing wrong this whole time?

I’ve never seen anything stating such, I just figure it can’t hurt. Then again, I always shake a Gatorade bottle before opening it.

 

[Household6]

Going by your earlier post, the latest CYA measurement was 40. That means your FC target range is 5-7. The target range doesn't mean that you raise FC up to any value in that range and let it come from there to the min FC level. Your aim should be to keep FC at all times in the target range - the min FC is more of a lowest ever limit for unforeseen circumstances. It is like an airbag that you want to have, but never actually want to see in your whole life. If your daily loss was 2ppm, then you could raise FC to 7 and top up when it reaches 5 after 24 hours. If your daily loss was higher, then I'd rather go above 7ppm when adding bleach, than risking to get below 5ppm. If you have extra bather loads, I can make sense to add a bit of extra bleach.

3.5ppm is awfully close to the min. One more swimmer with a weak bladder on that day and you're below. And the logs you have posted show that there were times with 0 FC - probably because something went wrong. But aiming to keep your FC in the target range at all times, gives you more room for things going pear shaped without getting below min FC.

Poolmath app shows range is 3-7. Target is 5.
My FC reports of 0 are due to laziness! As I told Lee, the purchase of the bot this year hasn’t helped improve my lazy as the water has been constantly clear all season with zero VISIBLE issues (minus the ph of course).
Your point is valid and I will improve!

 

[CraigChing]

Long story short, it’s hard to convince myself to mess with water that APPEARS clear.

Think of your pool like a dog. Would you wait to feed your dog until it looks like it’s starving? No, you feed your dog twice every day!

 

[Household6]

Think of your pool like a dog. Would you wait to feed your dog until it looks like it’s starving? No, you feed your dog twice every day!

Funny, I spend more on our dog every month than I do on our pool!
(Now if that’s not a commercial for TFP, I don’t know what is!)

 

[Household6]

Picked up a new bottle of R-0004 yesterday at Leslie’s. Asked for any ideas on why I couldn’t keep my pH down. Lady said she’s had several people ask about it this year. Only thing they’ve come up with is that it’s a result from the Sahara dust storm that moved through earlier this year.

Perhaps. But It’s likely more a case of old reagents for me.