Big mistake in trying to raise pH... please help!

[JWB]

Hi,

I had a serious green algae problem that finally subsided after six gallons of chlorine, brushing and numerous pool & filter cleanings. Unfortunately, my pH levels went way down and the upper 8" of my vinyl liner turned brown. Concerned about damage to my machinery, I stupidly added two pounds of sodium carbonate (all at once) to the pool to raise the pH. It didn't dissolve well and the majority of it ended up on the pool bottom as a blue silt. Now when I try to vacuum, it just runs through the filter and blows back into the deep end of the pool.

The chlorine level is off the charts. pH is up to 6.8 but I can't get a TA reading with my kit (water goes yellow but won't go red) and this worries me. I'm afraid to run the filter 24/7 if my equipment is at risk. Should I anyway? I'd appreciate some suggestions.

Thanks

Vinyl lined 16'x32' inground
DE Filter
Super Pump II
Hayward Navigator vac

[JohnT]

First, don't trust your pH test results when the pool is at shock level.

If the Sodium Carbonate is coming through the returns, you have a filter problem already.

The colors for the TA test change when the chlorine level is high. The color change is what's important, but you really don't need to worry about TA until you get the rest of the mess cleaned up.

Run the pump 24/7, but you should consider opening the filter and inspecting the grids for tears.

[aylad]

I don't think that your equipment is at risk as much as your liner is, and whatever damage it's going to sustain has been done already. As far as the sodium carbonate, you can try brushing the pool several times daily in an effort to help dissolve it faster or help the filter catch it, or you might want to consider vacuuming it to waste and starting over with borax dissolved in water and then poured in through the skimmer.

As JohnT said, your pH result is usually false when the chlorine level is above 10 ppm, but it's usually falsely HIGH--so don't ignore the problem, because your pH may be much lower than you think it is. What made it drop like that? Was it something you added, or has it been awhile since you checked it?

Janet

[CarlD]

Jan's right: if your FC is high, it give false HIGH pH readings, not false lows.

You can add a couple of drops of chlorine neutralized to the sample before you test it, or use the Taylor 0014 pH test, rather than the 0004, because it has neutralizer.

If your pH is UP to 6.8, you need to raise your pH asap. Try using Borax instead of Washing Soda (Sodium Carbonate). I'd add a box, SLOWLY, into the skimmer. Wait an hour and check pH. iF it's not over 7.0, add another box and repeat.

Good luck!

[JWB]

I don't think that your equipment is at risk as much as your liner is, and whatever damage it's going to sustain has been done already. As far as the sodium carbonate, you can try brushing the pool several times daily in an effort to help dissolve it faster or help the filter catch it, or you might want to consider vacuuming it to waste and starting over with borax dissolved in water and then poured in through the skimmer.

As JohnT said, your pH result is usually false when the chlorine level is above 10 ppm, but it's usually falsely HIGH--so don't ignore the problem, because your pH may be much lower than you think it is. What made it drop like that? Was it something you added, or has it been awhile since you checked it?

Janet

Thanks for the help everyone.. I'm not really sure what made it drop. I assume now that all the chlorine I added gave me a false reading. Could the chlorine boost have damaged the liner at the waterline, or something else? It's a nasty brown color.. kinda rough too. Fortunately it doesn't look bad further down towards the bottom.

I'll check and clean the filter tomorrow and attempt to vacuum out the silt. I may not have added enough DE this past cleaning. Hopefully it'll catch it. Thanks again...

[CarlD]

JWB:

Let's make it very clear: Too high chlorine can make your pH look HIGHER than it is, not lower.

Your pH was a very LOW 6.8--therefore if the chlorine had given it a false high reading, I SHUDDER to think how low it really is--probably around 6 or the high 5's.

In either case I'd be adding Borax--at least a full box at a time to raise that pH.

[waterbear]

Hi,

It didn't dissolve well and the majority of it ended up on the pool bottom as a blue silt.
The blue color could be an indication of copper in your pool and you might have precipitated cupric carbonate (copper carbonate).
The chlorine level is off the charts. pH is up to 6.8 but I can't get a TA reading with my kit (water goes yellow but won't go red) and this worries me.
Thanks

Vinyl lined 16'x32' inground
DE Filter
Super Pump II
Hayward Navigator vac
If the chlorine levels are very high it is normal for the TA test to go from blue to yellow instead of green to red since one of the indicators gets bleached out. The colors are on the pale side so it's harder to see your endpoint but the results are valid. If it starts out yellow and your pH is reading 6.8 with very high chlorine levels then your pH IS very low. The question is how did it get so low. Adding liquid chlorine or cal hypo shock would not cause that but the use of trichlor could.
The only other way your pH and TA could crash is by overdosing on acid.

[JWB]

Thanks...

Yes both the "pH Up" (from Home Depot) and now Borax turn "teal blue" when either broadcasted or "diluted and skimmed" into the pool. I've started a Borax regimen (1 lb every hour, recheck) and am vacuuming and cleaning the filter grids every two hours. Two of the grids look to be damaged so I'll be ordering new ones today.

My liner is worse than I thought. It's light brown everywhere except towards the deep end. I also have a metallic film on top of the water. I'm so disgusted with myself for not learning this information sooner. If copper is to blame for the staining, is there a solution?

I'll report some levels later... thanks again

[JWB]

Well it's been slow going but I have new information. After 8 lbs of Borax, my pH level is around 7.0... not much better. I took a water sample to a pool supply company and they got a TA level of 90. They said that the soda ash turned blue (and didn't dissolve well) because I most likely have high concentrations of copper sulfate in the water. They gave me a sample water bottle and suggested I come back in three days to test for metals. Apparently they have substrates that can work with newly stained vinyl pools. Pretty expensive I bet?.. but I'm desperate to find a solution for my stained liner.

I'm continuing to add diluted Borax through the skimmer and also brushing the blue soda ash off the bottom. I'm not sure why the pH isn't rising faster given the amount of ash being circulated in the pool? I hope I'm doing this right.

Thanks for your help and interest.

[aylad]

It'll be interesting to see the result of your metals test--if you do have a high metal content you can use sequestrant.....take a look at Marie's (mbar) posts in the metals forum--she's the resident expert and has given lots of good information when it comes to dealing with metals. Is your fill source from the municipal water supply, or is it from a well?

I believe soda ash also raises TA along with pH, which may be why you're not getting as much rise in pH as you expect, but I really think your pH was much, much lower than you originally thought, which explains the huge amount of Borax being used to get it back up to normal ranges.

Janet

[waterbear]

I already said that you had copper in your water.
Question is, where did it come from? Have you been using algaecide?

[JWB]

It'll be interesting to see the result of your metals test--if you do have a high metal content you can use sequestrant.....take a look at Marie's (mbar) posts in the metals forum--she's the resident expert and has given lots of good information when it comes to dealing with metals. Is your fill source from the municipal water supply, or is it from a well?

Janet

Thanks Janet I'll check that out. My water comes from a municipal source. From what I understand now, as this kind of water evaporates, the metals are left behind. That probably explains why the water has always had a strange metallic taste since we inherited this pool. I hope I haven't endangered my family by not taking action to correct it. Having never had a pool before, I thought it was normal.

[JWB]

I already said that you had copper in your water.
Question is, where did it come from? Have you been using algaecide?

No algaecide. The only tri-chlor I’ve used was in the two bags of powdered shock (40%), but that was six days ago when I was dealing with algae.

Actually, you said “it could be” copper so I wanted to get a second opinion. Sorry if it looked like I didn’t read your post. They basically backed up what you said but because I didn’t have a large enough sample, they couldn’t determine exactly what metals are present. I’ll find out later this morning.

Let’s assume I have an abundance of copper in the water. With the pool’s current state (FC 5+, pH 7.0, TA 90), can I treat the pool with a metal sequesterant, or do I have to get the pool chemistry in order? Also, any chance the oxidized metals are keeping my pH from rising past 7.0 despite 14 lbs. of soda ash?

Thanks

[CarlD]

Soda Ash=pH Up!=Washing Soda (Arm&Hammer)

This raises T/A as well as pH. T/A of 90 is nothing to worry about.