any way to control pH better?

[Furbabyvet]

Hi everyone. My pool water balance situation has improved greatly since I started BBB about 2 months ago. I took a water sample to the pool store(yeah, the one that messed me up so badly in the first place!) to cross check my numbers and the 20 year old slacker working there said I got an A+. Yea, me and yea, poolforum.com . I didn't bother to tell him it was no thanks to his advice!

My numbers are approximately:
FC 5
CC 0-0.5
pH 7.7 today and rising quickly
CH 260
TA 80-90ish
CYA 40ish
Borates 40-50 ppm
temp. is 84-86 F
sorry for ambiguous #s but I have a hard time discerning the test result at times.

Anyway, I am happy with the way things are going except for two things. One is that there is still a very scant growth of green algae just above the waterline mostly on the "shady" side of the pool. It's only in a few places, not the entire pool. Raising water level an inch, shocking and scrubbing haven't made much impact on it. I've also tried adding polyquat 60, phosfree, and have now added borates to somewhere between 40-50 ppm. The algae is still there.

The other problem is that my pH keeps going up to 8 or greater, no matter what I do. We do have hard water in this area of AZ, but I was really hoping the borates would help slow down acid demand. The way it goes right now, I would need to add acid 2-4 times per week to keep it below 8.

Any ideas on either of these topics? Sorry if I posted in the wrong section!

Tabitha

[PoolDoc]

Hey Tabitha;

You'd gotten two earlier responses, from CarlD and Waterbear, that were sort of going at cross-purposes, so I'm jumping in here. I moved those posts to the China Shop for now. They are in the "Algae, TA or what" thread.

As I understand it -- please correct me if I'm misunderstanding -- you have two problems, one urgent and one longer term or chronic.

The urgent problem is the algae. If it gets away from you, you'll have serious problems, so we probably need to get that under control ASAP. More chlorine is the solution, at least right now.

The chronic or longer term problem is a continuing rise in pH. This problem may contribute to your algae problem, since chlorine tends to be less and less effective as the pH rises. So, lowering your pH -- regardless of how why it keeps going up -- is probably the next thing to do, after you get your chlorine level up.

So, let's do this.

1. Raise your chlorine level to 15 ppm, and then keep it above 10 ppm till the algae is gone.
2. Add enough acid to lower your pH to 7.2 or so -- but NOT all at once. If you know how to handle muriatic acid (no splashes, wear glasses, use gloves, don't breath the fumes) it's cheapest and best for your pool.
3. Don't try to fix anything else, till the algae is gone.
4. BUT, do collect the info we need to see if we can tell what's going on with your pH.

Regarding doses, I don't see any indication of pool size, but if you post gallons, we can figure doses or show you how.

If you're not doing so, make sure your pump is running 24/7, till the algae is gone.

As far is information goes, please do all the following (but take care of the chlorine and pH first):

1. Post pool gallons, typical timer 'ON' hours, filter type.
2. Tell us what sort of chemicals you are normally using (labels, chemical ingredient)
3. Tell us what's been happening with your TA -- has it always been this low, or has it been going down lately?
4. Test your FILL water for pH, chlorine, Alk, Calc, and post those results.
5. Tell us if there is anything connected to your pool that would aerate the water (fountain, waterfall, spillover edge, attached spa, air jet, etc.)

And, let us know you have a problem with any of this.

Good luck!

Ben
"PoolDoc"

[Furbabyvet]

Hey, thanks a lot for the help.

1. Pebble Tech pool. 11,940 gallons. Sand filter. Pump runs 7 hr. during the night and 1 hr. during the afternoon.
2. I use 10% chlorine, 29% muriatic acid regularly. I have 2 trichlor pucks in my floater right now to help with chlorine and to add CYA. I have also added borax. As I mentioned, I’ve put in polyquat 60 a few times—once I put in a whole bottle, but then later just a few ounces per week. A month or so ago was the last time I added PhosFree just because we already had it from last year.
3. 6 weeks ago, the TA was 230. I followed the procedure outlined here to get it down so I could add borax.
4. FILL water pH 7.6, Cl 0.5, TA 110, CH 250.
5. There are no water features in the pool, although we have a “aerator” nozzle that can be turned on as needed. I only used this when trying to lower the TA.

My water test today:
FC 6, CC 0, pH 7.8, TA 90, CH 280, CYA 40, Bor. 40

I have the solar cover on and the water temp at 7:30 am is 83 F.

The algae is still there, although not as bright green as it has been at times. It is about 3/4 of an inch ABOVE the water line. Will I need to fill the pool more to affect this algae or will it get enough chlorine as is?

Two months ago, I fought off what I believe to have beeen mustard algae in the form of brown “dust” that had been there for over a year but I didn’t know what it was. There is no sign of the brown dust and the pool water is as clear as clear can be.

Tabitha

[PoolDoc]

FACT #1: I have the solar cover on and the water temp at 7:30 am is 83 F.

The algae is still there, although not as bright green as it has been at times.

FACT #2: It is about 3/4 of an inch ABOVE the water line.

Ok. I think I've got the picture.

As a general rule, when you are trying to fix anything with your water, your pool needs to be on 24/7. But, in your case, the problem is OUT of your pool, not IN it. And, since the chlorine is IN your pool, neither it, nor any algicide will do the trick.

Is your solar cover the type that you trim to fit? If it is, have you trimmed it to fit, so it ONLY floats on the water, and doesn't cover the edges at all?

PoolDoc

[Furbabyvet]

Ok. I think I've got the picture.

As a general rule, when you are trying to fix anything with your water, your pool needs to be on 24/7. But, in your case, the problem is OUT of your pool, not IN it. And, since the chlorine is IN your pool, neither it, nor any algicide will do the trick.

Is your solar cover the type that you trim to fit? If it is, have you trimmed it to fit, so it ONLY floats on the water, and doesn't cover the edges at all?

PoolDoc

I think I overstated the distance of the algae from the waterline. It's more like 1/4 inch above and it's in small patches, in the pits between the pebbles. It does seem to be wet in that area, though.

The solar cover is a trim-to-fit type that floats on the water. I only put it on yesterday, so it is definitely not the cause of the algae that's been there off and on for weeks.

I went ahead and brought the Cl. level up to about 18 ppm and the pH is somewhere around 7.4 and going down as I add a little acid at a time. The cover is still on-- should I take it off? Doesn't seem like it will affect what I'm trying to do.


Tabitha

[PoolDoc]

Hi Tabitha;

Be cautious about your pH. As your chlorine level goes above 10, your pH readings, if measured with phenol red drops, will be less and less accurate. At 18 ppm . . . unless you are using a calibrated pH meter, you really don't know what your pH is.

Regarding the algae -- are you saying that you have algae in the pits and rough places at the water line?

If so, lowering the water level, and using a 1:10 spray of polyquat will probably work. Just make sure you use a CLEAN sprayer, with no herbicide or pesticide residue.

Or, if you've got an old clean sprayer that you don't mind ruining, spraying with straight bleach, and then 'pressure washing' with a hose and nozzle and the re-spraying will probably work.

But, it depends on how deep the rough spots are: you can only kill algae you can reach!

Once the algae's gone we'll need to see what the situation is with your pH.

Ben
"PoolDoc"

[Ohm_Boy]

Pump runs 7 hr. during the night and 1 hr. during the afternoon.

I'm gonna jump in here and reinforce that your pump needs to be circulating 24/7 while you are trying to clear up algae. Lack of circulation can make algae VERY hard to get rid of.