Newbie's green pool

[George in Georgia]

I'd started this a few minutes ago, but something went wrong!

I've got green water. While searching the net for help, and after enriching my local pool store, I found you guys. Why should the pool care whether the hypochlorite ion is attached to a sodium ion or a calcium ion? Inquiring minds want to know.

A few details:

25,000 in ground, vinyl
SWG
Sand dollar 60 filter, new sand, Challenger 1 hp pump

Pool shop test results:
Saturation index -.8
TDS 4500
CYA 90
Tot Cl 1
Free Cl 0
pH 7.8
Tot alk 50
Adj tot alk 23
Tot hard 75
Salt 3100

So far the store has had me using A LOT of 48% cal, and most recently something called Swamp Treat (no ingredient statement either on jar or website) and a good deal of trichlor, probably the major source of the cyanuric acid.

The only removal of green has been from my wallet!

Monday they did a 4 hour test of a sample, I guess to measure chlorine demand.
After that test their recommendation is 28 lbs of 48% cal, broken into 3 doses 3 or 4 hours apart, 10lbs, 10lbs, and then 8lbs, dissolved in water before adding to the lime jello pool. This would be around $100.

Working with that 28 lb figure and The Pool Calculator it looks as though 36 or 37 96 oz jugs of 6% bleach might do the job. Does this seem about right? Should I follow their schedule of application for the bleach, 12 gal every 3 or 4 hours, with frantic brushing, of course?

When I told the pool store that I was investigating household bleach they were incredulous, to put it mildly. But with a vinyl liner I don't need calcium ions, they'll only gunk up the SWG.

I'm really glad I found this site! One not to be named pool store person recommended copper algaecide even though I told them that I though the copper would plate out on the salt cell. Geez!

Any help, advice, hand holding y'all can give would be much appreciated!! Thanks!

[sturev]

your other post is here: http://www.poolforum.com/pf2/showthread.php?t=10042

[aylad]

Wow, I'm glad you're here, and know better than to keep making that pool store richer without getting a clear pool!!

You were absolutely right not to add the copper algaecide, and that all the trichlor is probably the source of your high CYA. However, depending on what SWCG you have, this is one of the situations where having a high CYA is actually a good thing!

In a pool your size, using 6% bleach, you can raise your Cl to 20 ppm by adding 8.5 gallons. With a CYA that high, you need to shoot for between 20-25 ppm and consistently keep it there until the pool clears up and you're no longer losing any chlorine when you test at night after the sun is down and again in the morning before the sun hits the pool. The key here is consistency, so you'll need to test and add more bleach each time to get back up to the 20-25 range. Each 1/2 gallon will raise your Cl by approximately 1 ppm, so you can use that as a guide when retesting. Brush the pool daily, keep the pump/filter running 24/7 and backwash the filter as your pressure indicates. I would not use any more dichlor shock--I would just use bleach to get the pool cleared up, and then the SWCG should be able to take it from there.

Your pH is a little high, you might want to lower it using muriatic acid to 7.2-7.4. Keep in mind that while your chlorine is at shock level, though, the pH probably will give falsely high test results, so you might want to adjust that first.

I would absolutely not put any more of the Swamp Treat (especially since there's no listed ingredient :eek: ) or anything else in the pool other than acid and lots and lots of bleach.

We're really good at hand-holding around here, so shock the pool and keep us updated on how it's going!

Janet

[sturev]

You might check prices and compare the price of regular 6% bleach and 12% chlorine in your area... since it looks like you're going to need quite a bit, it might be cheaper to go the chlorine route. The pool store should/might carry liquid chlorine :eek:

[George in Georgia]

Many thanks, guys! I'm off to buy bleach. Am I right in assuming that if I go a bit overboard in the dosage - say 11 gal instead of 8.5 - that the only lasting consequence would be a small rise in salt level? I'd think that adding bleach in the evening might be a good idea, to avoid uv.

Here in Georgia, just south of Atlanta, we have a loooong pool season. 'Course our personal season will start a little late, but we should be splashing well after labor day.

Thanks again. I'll keep The Collective Mind posted.

[aylad]

By going overboard in the doseage, you're still okay and won't really notice an appreciable rise in your salt level. 11 gallons would take it up to 26-27 ppm. You just don't want to go too high in a vinyl pool and risk fading your liner.

Adding bleach in the evening is probably when you'll get the best bang for your buck, because it doesn't have to compete with the sun, but the key to clearing up the green is going to be consistency in keeping it above 20 ppm.

Janet

[George in Georgia]

Again, many thanks!

I'm going to hop over to the cleaning machines, where I can perhaps make a contribution on the Diagnostic Dolphin front.

[George in Georgia]

An update. Yesterday evening added about 11 gal of 6% bleach. This morning added another 8 or 9 gal., plus 32 oz 50% algaecide. At about 2pm added 9 gal bleach, plus some more algaecide.

pH is holding about 7.5. There is essentially no free chlorine present just before the next bleach addition. I suppose the algae is using it up. The pool does seem to be clearing a bit, I can see further down into the "lurking murk."

I guess we'll just keep on truckin', unless anyone has a better idea. I think we're getting a rep at Kroger and Publix as "those crazy bleach folks."

[Watermom]

Keep hitting it with bleach as you have been. The only algaecide we recommend is Polyquat 60%. A lot of the other algaecides will cause foaming or have copper in them which is something you do NOT want in your pool. Algaecides are pretty good preventatives but don't really help kill an existing algae bloom much.

[George in Georgia]

I hear and obey, O Great Ones!

The algaecide has no copper in it. I am an inverterate label reader. Is my guess about the reason that the Cl is so low correct, that its being "eaten" by the algae?

Again, many thanks to all for the advice and encouragement.

[PoolDoc]

. . . . I am an inverterate label reader. . . .

Just doing a quick scan through the forum for unanswered threads, and saw your comment, which includes a bit of a misspelling, which I read as

"I am an invertebrate label reader"

My older son does "invertebrate animal husbandry" (ie, he feeds and plays* with the nautiluses and octopuses) at the Tennessee Aquarium, so your post got the "Huh??, better read that again" reaction.

But to your question: Yes, remaining algae can definitely cause high chlorine demand.

PoolDoc



* The official 'PC' term is "enriches", not "plays with". :rolleyes:

[Spensar]

When I told the pool store that I was investigating household bleach they were incredulous

When I get the pool store to do a test, I tell them I use sodium hypochloride, or liquid chlorine.

[aylad]

The algaecide itself can also be eating up your chlorine. Better to skip the algaecide and stick with bleach.

Janet

[George in Georgia]

I think we're almost there! There is no visible algae. Cl is about 4ppm via the SWG; no bleach added since yesterday morning, 24 hours ago. pH is about 7.2, I'll probably pick up some borax to raise that a bit.

The water is cloudy. Could that be dead, bleached out algae particles? Any suggestions for clearing that up? I've seen various flocculants at pool stores but I'd like to hear from you experts?

Pool Doc, my regards to your son at the Tennessee Aquarium. It's a great place. I like it better that the aquarium in Atlanta.

Many thanks!

[Watermom]

Run your pump 24/7. Dead algae takes a bit to filter out. Better not to add floc at this point. Post a current set of testing numbers.

[George in Georgia]

I added about 2lb of borax, pH is now 7.5. Cl about 4ppm, NO visible algae! I think I'll hit it tonight with about 8qt of 6% bleach, just on general principles. Now that things seem to be returning to normal, the SWG seems to be operating normally. It had insisted that the salt was off, and that the cell needed inspection/cleaning, even after the HCl acid bath.

Nice to be getting back to normality, thanks to you folks.

[aylad]

Good job!! Isn't it great to see progress?? Just keep the filter running, and clean it as necessary--the chlorine kills the algae, but it's the filter that removes it from the pool.

Happy swimming, hope you're enjoying your 4th!!

Janet

[George in Georgia]

An update.

We lost a little ground, having been away for 2 days. BTW, it turns out that Costco has Chlorox 3 big jugs for $7.35, the best price on any brand that I've found in this area.

pH is 7.5, Cl holding at 5-10 since adding about 3 gal 6% bleach 24 hours ago. Ppm total alkalinity 120, cyanuric acid at about 40. I've added about 12 lb of baking soda, and 4 lbs of borax. I suppose I should raise the cyanuric some given the SWG.

There is no visible algae, but the water is cloudy. I'm filtering 24/7, backwashing generally shows bits of leaves and pine needles from the bottom, which I can't see. Any thoughts? Maybe a flocculant? I know it would be safe to swim in, but not appealing. And as someone (Poolmom?) mentioned, someone in trouble would be hard to see.

The Dolphin is sucking up dead algae - we're switching to disposable bags until things settle down.

Thanks, all!

[aylad]

Hold off on the flocculant for now....with the dead algae that was already clouding the pool, along with the amounts of Borax and Baking soda you've added, just give the filter some time to catch up....if you had a pool full of algae when you started this journey, it's going to take awhile for the filter to get it all out. Remember the POPP!! (Pool owner patience and persistence) :)

Janet

[George in Georgia]

Thanks, Janet!

I keep in memory the first two years we were in the house, when pool maintenance was so easy, and the ease and pleasure of late afternoons by the crystal clear pool....precious memories.... I intend to give it 2 big bottles of bleach tonight, check the Cl after an hour or so, and then again in the morning before the sun hits the water. At least here near Atlanta we can probably swim til the end of September.

I think I'll try some of the DE equivalent in the filter, 1/2 cup at a time to give a 1 lb pressure rise. What's to lose, only some cellulose fiber....

[aylad]

It won't hurt to try. Remember that the pressure rise takes a few minutes, so add a little, give it 5 minutes or so, then add more if you need. If your pressure rises too much you can always backwash it out and try again.

Let us know how it goes

Janet

[George in Georgia]

Well, the pool holds Cl overnight. Tests at about 11 AM this morning:

pH 7.2
ppm Cl no bleach added yesterday evening 5
ppm tot Alk 120
Cyanuic acid 30 - 40 ppm (I haven't found locally a proper test kit, I'm using strips)

I've added some calcium carbonate to raise the pH to 7.5 - 7.6

The pool is still cloudy, but no green, even after running the filter 24/7 for well over a week. Any suggestions? Time for flocculant? Any other ideas? This problem is getting depressing....

[aylad]

Did you try the DE? And if so, did you see any improvement? Also, at the beginning of this thread you stated that the pool store had you using "a LOT" of cal-hypo--what's your current calcium hardness number?

Jant

[George in Georgia]

Hi Aylad -

I've yet to find the proper amount of DE or the fiber equivalent from the pool store which will not "clog" the filter. I'll continue to experiment.

Calcium hardness is reported by the pool store as 100 ppm, they cite as ideal 200 to 400.

[aylad]

Ideal calcium for a plaster or concrete pool is 200-400.
For a vinyl pool, 100 is fine--but was that a recent reading, done after the large amounts of cal-hypo that you used? As far as the DE goes, start with 1/2 cup into the skimmer and watch your pump pressure for a few minutes. If it rises to 1 psi, then stop. If you see no rise, then add another 1/2 cup, which will probably do the trick. If you get over 1 psi rise, then backwash it out and try again.

Janet

[George in Georgia]

The calcium hardness was a recent reading. I'm off to the pool store to see if they've got a cyanuric acid test kit; I'll have them test a sample for chuckles ;-)

[Watermom]

Remember that when adding DE to a sand filter, it sometimes doesn't show the pressure increase immediately, so don't add more for at least 30 minutes. If, after that time, you still don't show the 1psi increase, then add just a bit more.

[George in Georgia]

Well, I knew the liner was due for replacement, but I'd hoped to be able to wait till fall. But, after a drop in level of 4 inches in one day....Bwaaah!

I've added flocculant in the hopes of being able to see the bottom so I could check for a leak and patch it, maybe. I've also heard the suggestion of adding food coloring at potential leak points - drain fitting, returns, etc, to maybe spot a leak.

Of course fresh water would let me have the proper chemistry from the beginning. Now if only the SWG cell doesn't fail.

Any other ideas? This summer is turning into a nightmare. At least our insurance covered replacing the roof, thus freeing up money for the new liner. Grrrrrrrrrrrr!

[George in Georgia]

More complications. I suspect a leak in the returns. I'm posting under Repairs.

And the water was clearing nicely....

Thanks for the help on water quality. I'll be ready when the liner/leak problems are resolved.

[aylad]

I hate to hear about the new leak problems--just when you were finally getting the water cleared up!! :mad:

Hoping for an easily located and fixed problem, so that you can start enjoying your summer.

Janet

[George in Georgia]

Janet, thanks for the good wishes. The Leslie's flocculant worked well. I've found a leak stopper which at least one of The Collective Mind here at the forum used successfully three years ago. I've sent him a message asking for an update.

George