High PH

[Newerabs]

Hello, I have a question about high PH levels in my pool. I have a 18 ft circular Pool (7600 gallons) and a Intex 3,000 GPH Sand filter. About 3 weeks ago I got back from a work trip and my pool was green. I did the SLAM process and now it's nice and blue again. There is still algae hanging around on the floor of the pool but I've been able to brush and vacuum for the most part.

My issue now is that my PH/TA is really high. When I tested last night (using Taylor k-2006) my PH was above 9 and my TA was at 440. I looked at the PoolMath calculator and when I put in 9 with a goal of 7.5 for PH and then put in 440 with a goal of 100 for TA it asks me to put in 103 oz of Muriatic acid. However, if I bump my current PH up to 10 it asks me to put in 332 of muriatic acid which is significantly more.

I'm wondering what would be a good amount of muriatic acid to put in?

My current FC level is 2 (I know I have to get this up a little) and my CYA level is probably around 20 (I'm in the process of raising this to 40).

Thanks for the help!

 

[tim5055]

Right now get the pH down to 7.2 with acid (ignore TA for now) and re-start your SLAM. Visible algae means you stopped too soon. The clear water part of the SLAM means you see no algae.

Lowering TA is a multi step process, not a one time addition of acid.

 

[Newerabs]

I guess my question though is how much muratic acid should I be dumping in? A couple weeks ago I noticed my pH was high and dumped a gallon of muratic acid in my pool and it didn't seem to do a thing. I just can't seem to get my pH level down to acceptable levels.

 

[Mr Bruce]

If you dumped a gallon of MA in a 7600 gallon pool and it didn't do anything, that wasn't MA.

Always use PoolMath to determine correct amounts.

 

[Marlahoutex]

What percentage of MA are you using? What is the date on the bottle? Maybe it was old. Not an expert, just throwing out ideas....

 

[Newerabs]

If you dumped a gallon of MA in a 7600 gallon pool and it didn't do anything, that wasn't MA.

Always use PoolMath to determine correct amounts.

I'm sorry I misspoke. It did lower my pH but a week later it's right back up to high levels. I guess another question is what is making my pH so high? I don't know anything about pool chemistry so I apologize if it's a dumb question.

 

[tim5055]

Aeration causes pH rise. This could be a waterfall, returns spashing the surface, kids splashing around - anything like that. Plus, high TA causes it to rise faster.

But, we need to eradicate the algae before we worry about the TA.

 

[Newerabs]

Aeration causes pH rise. This could be a waterfall, returns spashing the surface, kids splashing around - anything like that. Plus, high TA causes it to rise faster.

But, we need to eradicate the algae before we worry about the TA.

It's interesting you say that. I have a Summer Escapes pool and the return is a little above the water line so my filter has been running pretty much non-stop while I've been slamming (about a week and a half) and it's splashing a lot of water on the surface.

 

[tim5055]

It's interesting you say that. I have a Summer Escapes pool and the return is a little above the water line so my filter has been running pretty much non-stop while I've been slamming (about a week and a half) and it's splashing a lot of water on the surface.

That, plus your high TA could do it.

So, let's SLAM and get rid of the algae.

 

[atttech-2]

My issue now is that my PH/TA is really high. When I tested last night (using Taylor k-2006) my PH was above 9 and my TA was at 440. I looked at the PoolMath calculator and when I put in 9 with a goal of 7.5 for PH and then put in 440 with a goal of 100 for TA it asks me to put in 103 oz of Muriatic acid. However, if I bump my current PH up to 10 it asks me to put in 332 of muriatic acid which is significantly more.

I'm wondering what would be a good amount of muriatic acid to put in?

Thanks for the help!

As others have said sounds like the SLAM is not complete, on the pH question I think the reason it is telling you to add so much MA when you put ever higher numbers in the calculator, is that pH is logarithmic so a seemingly minor increase in the number is a major increase in the amount of MA needed to deal with it. I think a safe amount would be 1/4 gallon of 31% at a time with he pump running and check the progress every 30 min or so. because it's logarithmic I would think you can be more aggressive (add a bit more) to start and back off as you get near your target.

 

[Newerabs]

That, plus your high TA could do it.

So, let's SLAM and get rid of the algae.

I guess I'm not sure how I'll know once all the algae is gone. Right now my water is crystal clear but there is sandy brown stuff on the floor every morning. Is that "dead" algae? It seems to brush up pretty easily and I can vacuum it up (most of the time). But it just comes back the next day. Sometimes there is a lot of it sometimes not. I have no idea how algae works (obviously)

 

[flipr]

I guess I'm not sure how I'll know once all the algae is gone. Right now my water is crystal clear but there is sandy brown stuff on the floor every morning. Is that "dead" algae? It seems to brush up pretty easily and I can vacuum it up (most of the time). But it just comes back the next day. Sometimes there is a lot of it sometimes not. I have no idea how algae works (obviously)

Been there, done that, got the T shirt. Follow the SLAM process, mainly the OCLT test. Sun eats up Chlorine, so test FC after sun down, and write down your level. Then check first thing in morning. If more than 1 ppm FC was used it, it was the organics in the pool, and your SLAM isn't over yet.

When your FC doesn't change overnight, all the organics are gone. Also be sure to clean your filter, as the organics might be hiding in there too. My cartridge was full of little ants/bugs, and my SLAM wouldn't finish until I got rid of those critters.

Just my advice