VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Water bugs, swimming insects and sweat bees.
Foaming bubbly water. Frogs in the pool.
Dead animals in the swimming pool.
poolmama

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby poolmama » Mon 18 Jun, 2007 00:08

15 foot above ground vinyl pool (5000 gallon)
I use Pool Time test strips with the following readings:
Total Hardness: 250 (OK)
Total Chlorine: 3 (OK)
Free Chlorine/Bromine: 3 (OK)
ph: 8.4 & higher (Very High)
TA: Off the chart!!!!!---higher than 180
Stabilizer: 50 (OK)

I have shocked the pool and added a almost 6 lb of ph- (sodium bisulfate) in the last 5 days and it doesn't seem to change any of the readings. The water is mostly a clear brown color (rust??) and when I clean the filter (which I do at least 3 times a day), there is alot of brown residue that rinses off. The sides and bottom of the pool are clean (no residue collecting on the surfaces). I have also noticed MANY black water bugs in the water (not surface bugs-but underwater swimming bugs).
I am at my wits end as to how I can balance the water and clear it up.
my kids want to just jump in and swim ---would it be safe to let them do that?
PLEASE HELP!!!
I am new to this...
Thanks!


Buggsw
Swimming Pool Superstar
Swimming Pool Superstar
Posts: 421
Joined: Sun 13 May, 2007 23:26

Postby Buggsw » Mon 18 Jun, 2007 23:07

Ditto to all the other times your post has been answered.
smcrea
Pool Care Proficient
Pool Care Proficient
Posts: 33
Joined: Tue 15 Jul, 2008 12:24

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby smcrea » Tue 26 May, 2009 16:06

I see that your problem was a year ago.

Did you ever fix the problem?

It sounds to me that your effective FC is useless because your PH is so high.

Your Ph is jumping high because your TA is way to high.

Therefore the root problem is your TA.

I have seen a lot of discussions on slugging vs broadcasting acid to reduce your TA.

My personal experience is that slugging acid does lower TA.

Use a 30% Acid.. not the 15% from Home Depot.

Slug in the deep end 1 pint a day in the same spot at the deep end. Don't mix it, let it dissipate on it's own. Do this every day and monitor your TA, your Ph may go low for a while.. just don't let it go to low. If it does then reduce the amount of acid a little just to stop any damage to equipment. keep your filter running 24/7 while your problem exists.

It may take a couple of weeks to get your TA down.. but when it does then you should see your Ph and it should be much more stable.. try keeping it at 7.6 my adding enough acid each day. Use an acid demand test kit.

Your Chlorine should then start to work effectively. Then you can give it a good hard shock.

I would keep your FC at around 4ppm.

Steve.
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby chem geek » Tue 26 May, 2009 19:07

Adding acid will always lower the pH and the TA and then subsequent outgassing of carbon dioxide will raise the pH with no change in TA. But why wait weeks for this when the method is clear as described here. The process is greatly accelerated at lower pH and with aeration. Forget slugging it and that can cause damage from acid pooling. Just lower the overall pH of the pool water to 7.0, aerate a lot, and add more acid as the pH rises. You'll lower the TA a lot faster that way, and more safely.
smcrea
Pool Care Proficient
Pool Care Proficient
Posts: 33
Joined: Tue 15 Jul, 2008 12:24

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby smcrea » Wed 27 May, 2009 12:10

Thanks for the advise....

So running my waterfall for lets say a day in my 10,000 gallon pool should effect my TA?... I'll give it a try!

Actually I have been a bit worried about any damage to my pool through slugging.

How would you recommend that I add my daily acid?

I have a new shotcrete pool with an exposed aggregate finish. I'm using around 1/2 pint of 30% acid each day to keep my Ph in check. My TA is 90 which I heard is good for a SWG pool.

I may start mixing the acid with pool water in my bucket and broadcasting.. would that be a better way and reduce potential damage to my pool finish?

Thanks,

Steve
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby chem geek » Wed 27 May, 2009 13:20

smcrea wrote:Thanks for the advise....

So running my waterfall for lets say a day in my 10,000 gallon pool should effect my TA?... I'll give it a try!

Actually I have been a bit worried about any damage to my pool through slugging.

How would you recommend that I add my daily acid?

I have a new shotcrete pool with an exposed aggregate finish. I'm using around 1/2 pint of 30% acid each day to keep my Ph in check. My TA is 90 which I heard is good for a SWG pool.

I may start mixing the acid with pool water in my bucket and broadcasting.. would that be a better way and reduce potential damage to my pool finish?

Thanks,

Steve

Steve,

It sounds like in your situation you already have the pH rising due to the new pool plaster. If you ran the waterfall, that would cause the pH to rise even faster (aeration causes the pH to rise with no change in TA -- it's the addition of acid that lowers both pH and TA). So I don't think you need to run the waterfall and in fact should probably not be running it right now since you've already got the pH rising.

Your TA could be lower at around 80 ppm, not lower than 70 ppm, and you may need to increase the Calcium Hardness (CH) to keep the saturation index at around -0.2 to -0.1 which is good for an SWG pool. You can use The Pool Calculator for this calculation -- don't forget to include the salt level and temperature. Note that your Calcium Hardness (CH) will be increasing from the curing of the pool plaster.

Since you are regularly adding acid anyway, your TA will drop on its own so you don't need to do any special procedure. 1 cup (1/2 pint) of full-strength Muriatic Acid (31.45% Hydrochloric Acid) in 10,000 gallons will lower the TA by 3.1 ppm so that's around 22 ppm per week. You'll probably need to add some baking soda every so often (once a week) to prevent the TA from crashing.

I would say that you should add acid slowly over a return flow with the pump running and then lightly brush the side and bottom in the area where you've added the acid. After weeks and a few months, the amount of acid you need to add will drop as the plaster gets more cured. After a year, the curing is very slow and after 2 years there should be no detectable pH rise from the plaster, though your SWG will still tend to have the pH rise. Keeping a lower TA helps as does keeping the CYA near 80 ppm (requiring an FC of 4 ppm) and also using 50 ppm Borates in the pool. These adjustments will reduce the rate of pH rise in the pool. See Water Balance for SWGs for more info. However, during this early curing phase (first month or two), follow the instructions of your pool builder so that the plaster cures the way it should.

Richard
smcrea
Pool Care Proficient
Pool Care Proficient
Posts: 33
Joined: Tue 15 Jul, 2008 12:24

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby smcrea » Wed 27 May, 2009 18:33

Hi Richard,

Thanks for the great advise... this is the first time I've had a pool. I read numerous articles and books on water chemistry while the pool was constructed.

I do actually have a Taylor 2006 kit and find the little Scaling Index calculator wheel extremely handy. I use it regularly. My current water chemistry is:

FC = 4ppm
TA = 90ppm
Ph = 7.6
CH = 290
Water temp is 84

Which gives me an SI of around -0.16 I believe.

The strange thing that I've noticed is that my TA seems to have hung at 90ppm.. it doesn't seem to move anymore?.. when I started out it was up at around 140ppm.. Why is that i wonder?

I do ph test and acid demand test nightly.. I have found that if the acid demand test tells me to use 1/2 pint of 30% then I'll give it 3/4 pint, as the Ph rises so rapidly throughout the day that if I don't then I'm way up at 8++ that evening.. it's rather frustrating really. I understand that getting my TA lower will help reduce that, but at 90ppm I don't think I'm doing to bad, and as I said.. it's seems to be hung up at 90ppm.

My CYA is at 65ppm... I was thinking of raising it to 70+ but my Pentair intellichlor -40 is only running at 38% which is pretty low. I read all sorts of reports on how nasty CYA is, so was dubious about raising it anymore than I had to!!

I do have one other question though... I read in the books that never pour all the junk that the pools shops try to sell you into your pool!... which I don't.. the only thing that I put in is acid and my chemistry is pretty text book good (modesty apart :oops:

However I did take a water sample into the pool shop.. actually it was to get the CYA checked because this test uses loads of my Taylor test chemical!.. so I thought I'd use there's instead of mine! :D. Anyway they did a Phosphate test which I'd never done.. and it came back showing massive phosphate levels. I have no idea where it came from. I suspect that it came from the guy who originally filled the pool... he put a metal sequesting agent in as he filled it which I now understand to be loaded in phosphates. The level was 2500ppm.

the guy in the shop tried to sell me a 'natural' phosphate removal chemical which supposedly puts a film on your filter that takes the phosphates out. I ignored his urges to buy the stuff and went home to research. I came up with several articles that say that phosphates are really bad and need to be removed. So to cut a long story short I bought and added the chemical.

I'll go back next weekend to get them checked again.

where I'm coming to is that in daylight my water looks crystal clear.. but at night when I put the pool lights on I can see very minute particles floating in the water in front of the light. I'm not sure if they were there before I put the phosphate removal stuff in or it was the stuff that introduces them. It's not a problem.. because my water looks so clear.. I guess that i'm just after perfection... I am so reluctant to buy a clarifier as I have no idea what the pay back on that is.

As I have read and try to follow: everything that you add to your pool will have a side effect.. I guess that's how the pool shop earns it's money!

What's your take on this?

Thanks,

Steve.
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2382
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

VERY high ph & TA, brown water & bugs. PLEASE HELP!!

Postby chem geek » Wed 27 May, 2009 22:43

Steve,

You may be adding less acid than you used to so the TA wouldn't drop as fast. You also could have high TA in the fill water so with evaporation and refill that will add to your pool whatever is in the fill water (usually CH and TA). You might test your fill water for TA and CH.

My pool has 2000-3000 ppb phosphates and I keep algae from growing simply by maintaining a sufficient Free Chlorine (FC) level relative to the Cyanuric Acid (CYA) level. Others on pool forums have even higher phosphate levels with no problems. It is true that phosphates (and nitrates) are algae food, but its not like having more food leads to uncontrollable growth. Even with all the food in the world, the algae growth is still limited by sunlight and temperature. Algae doubles in population in 3-8 hours under these ideal condition. When the FC is at least 4.5% of the CYA level for an SWG pool, the chlorine kills the algae faster than it can reproduce regardless of the phosphate level.

You should consider phosphate removers the same as an algaecide. It is yet another way to prevent algae growth, but not the only way and it's extra cost. Your cloudiness at night is most likely from the phosphate remover since it will precipitate phosphate (as lanthanum phosphate). It should mostly get caught in the filter, but that depends on the efficiency of your filter.

The reason you see articles about phosphates being so evil is not only because pool stores want to sell phosphate removers at great profits (which they do because that's what the manufacturers tell them), but also that no one talks about the chlorine / CYA relationship so for pools using Trichlor tabs the CYA builds up but the FC isn't proportionately increased and algae develops. Phosphates are tested and by definition there must be some in the pool or else algae won't grow so voila, a phosphate remover sale. For SWG pools, the SWG manufacturers mostly say to have the CYA at 60-80 with 70-80 ppm being "best" and this is to reduce breakdown from sunlight and keep the SWG on-time low which helps reduce the rate of pH rise. However, they also say 1-3 ppm FC which is too low (should be about 4 ppm FC with 80 ppm CYA) so algae can develop even in an SWG pool and again phosphates are seen as the culprit where at the high CYA level it seems to take a LOT of chlorine to kill the algae. Some even claim the phsophates themselves consume chlorine which is just pure bunk. It's nascent algae growth that consume the chlorine, even before the algae becomes visible (even before dull/cloudy and then green).

As for where your phosphates came from, it's possible it came from a phosphonate-based metal sequestrant (HEDP) though it's more likely it's in your fill water. My fill water has 300-500 ppb phosphates put in by the water district as a corrosion inhibitor. Phosphates (and nitrates) are also in fertilized soil so could get blown into the pool. Phosphonate-based metal sequestrants only very slowly break down from chlorine so don't release phosphate very quickly. EDTA metal sequestrants, on the other hand, break down more quickly though do not add to phosphates when they do -- generally, HEDP is better as a metal sequestrant.

As for your CYA level, if you raised it to 70-80 ppm and set your SWG so that your FC was at 4 ppm FC, then I'll bet your on-time would end up being a little lower than it is now. Of course, if the pool store was correct that the phosphates were leading to a lot of algae growth, then you should already start to see a lower demand for chlorine and be able to turn down your SWG on-time. At 65 ppm CYA, you should have a minimum FC of at least 3 ppm. If you lower your SWG on-time, then that should reduce the rate of pH rise. It's from a combination of carbon dioxide outgassing, which occurs more at higher TA, and also from chlorine outgassing from chlorine gas from the SWG that doesn't fully dissolve. This tend to be more of a problem with the SWG is close to the pool -- i.e. not in a long pipe run.

Another alternative to take the edge off of algae growth without having to spend money on a weekly algaecide or a phosphate remover is to use 50 ppm Borates in the pool. This is not only a mild algaecide (algistat), it is an additional pH buffer and will also let you have an even lower TA while still keeping the pH buffered. It also gives a clear shimmer to the water and reduces the chance of calcium scaling in the SWG cell. All of this is in the Water Balance for SWGs link I gave in an earlier post.

Richard

Return to “General Pool Water Problems”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests