In a normal pool, does anything *mix* the water to aid the filter?

[Danny D.]

I like this idea the best, as the algaecides stain the pool, and are expensive anyway.

Muriatic acid is about as cheap a chemical you can get, and I already have four gallons of the stuff (since I buy it by the case).

So, I'll figure out how much to add to lower the pH (my pool is 38,500 gallons) from 7.5 to 7.2 ...

BTW, here's an interesting read on phosphates:

Their conclusion: "The largest source of pool phosphates appears to be from scale and stain products and not environmental".

Their recommendation: "The author?s recommendation: take phosphates out of pool water when they exceed 1000 ppb (300 ppb is a sufficient reduction level), use a low or non-phosphate scale-stain product, maintain adequate chlorine levels, keep pool water pH within proper range, and use an algaecide especially for pools with persistent algae blooms."

But, I'm still googling and trying to form an opinion on what to do about the light algae on the walls ...

[gonjah]

I just add 2 cups and check the next day. Remember "acid to water just like you outta." I dilute mine in a five gallon bucket and then add to pool. You shouldn't add too much at once anyway.

In line with what they say at the pool store. They only get concerned at

800 ppb. It gets real hard to measure at below around 500 ppb. That's why I let them do I at the pool store and at this point it's guessing. They say 100 because they can't get a reading. I have a test kit but it always reads zero. As far as sources? I don't know. Nothing I use seems to add phosphates per se. I figure it comes from some where in the environment. I'm probably using the PR10000 now more for the filter assist. In a year I might use a pint. Point is, once you get phosphates out, if you're not using something to spike it, it's not something you have to be too concerned about. A monthly test at the pool store should be fine. If you get a reading, add a small amount of PR-10000. Re-test next month. Ask to see the results. They maybe insulted but tell them you're just curious. They might tell you it's high just to sell you some high priced phosphate remover. They don't do that here but I wouldn't put it past them.

[Danny D.]

I'm all for making my own solutions out of the basic chemicals.

Reading deeper on PR-10000, I find this: "the Orenda PR-10000 phosphate remover appears to primarily contain lanthanum chloride (note under toxicity data the acute oral effects as 100% LaCl3). The pH is low for the product and the thermal oxidative decomposition can produce fumes of hydrogen chloride (i.e. hydrochloric acid) and metal oxides. This is consistent with lanthanum chloride because it hydrolyzes in water to produce lanthanum hydroxide and hydrochloric acid, thereby lowering the pH (or alternatively, putting lanthanum chloride into an acidic water solution can make it less likely to form lathanum hydroxide) and with heat this can produce lanthanum oxide which is a metal oxide."

Googling for Lanthanum Chloride, I start with Wikipedia:

which confirms it's use to precipitate phosphates from solutions.

The MSDS for Lanthanum Chloride:

gives the CAS number as Lanthanum chloride 10099-58-8

It's about a dollar a gram for the 99.99% anhydrous stuff:

So, the question is what is the dosage (in grams) of LaCl3 in PR-10000?

[gonjah]

Don't know. When you find out let us know. I use it in very small amounts. Like I said, I think I'm using it more as a filter assist rather than a phosphate remover since I haven't had measurable phosphates for as long as I can remember. Maybe a couple of years now.

[gonjah]

Right. I seems expensive but it's concentrated. There are cheaper.

"Phos Free" for example. Seems cheaper but the dose is much larger. This is the stuff they pimp at the pool store.

There is a guy here that did the comparison in great detail. PR-10000 was the clear winner. The pool store doesn't want to talk about PR-10000.

[Danny D.]

I'll ask around, as I know some good chemists.

It would be nice if the $1 a gram Lanthanum Chloride is used in minute doses, say, a gram at a time. Apparently it will precipitate the orthophosphates, so, the water may need a clarifier (or just time).

[Danny D.]

From what I've read today, the Lanthanum Chloride in PR-10000 *does* precipitate the phosphates, and the PR-10000 also has a standard clarifier to prevent the pool water from looking cloudy from the process.

The main filter is actually what seems to pull out the phosphate crystals that are formed. One caveat is that only orthophosphates are removed (so the organic phosphates apparently remain ... but I need to clarify that with more detail).

If we're going to remove phosphates, most of what I read did agree with you that the PR-10000 stuff is the best buy; however, I'd bet that anhydrous Lanthanum Chloride, at $1 a gram, *might* be even cheaper and more effective.

I'll let you know what I find out.

[Danny D.]

I usually pour about 1/3 to 1/2 a gallon at a time as my pool is almost

40,000 gallons.

However, I sometimes go over too far - but not usually with just 1/3 of a gallon. I have guests today - so I'll try it later.

(Right now I have to figure out why the fans and A/C aren't working ... normally I don't bother - but with guests ... I care all of a sudden.)

[Danny D.]

I'm going to have mine checked at Leslie's and report back.

Me neither. All I add are acid, liquid chlorine, and Trichlor tabs (in the three floaters).

Most of what I'm reading is saying it would take a huge amount of wind-blown debris to be added by the environment; but, maybe it's inherent in the pool water from the well or town?

Makes sense. If it's out, and it doesn't come back in, then it's gone. (I wish weeds were the same way!)

I will probably do this: a. Get the pool store reading b. Meanwhile, I'll research Lanthanum Chloride by the gram c. If the pool-store reading is high, I'll add the lanthanum chloride.

Then I'll report back.

[Danny D.]

It's not affecting the clarity of the pool, per se.

It's hard to snap a picture of it, but, in the morning, the pool is nice and clear.

Then, I brush the walls (the pool is 60 feet long so there is a lot of wall) and I can see the dust billow up lightly behind the wire brush. But, it only makes the pool unclear for about a half hour or so, as, over time, the filter gets it or the cleaners disperse it or they settle back to the ground.

So, in effect, it's only unsightly (a light green on the sides, mostly at the deep end and in the nooks and crannies around steps and corners).

[gonjah]

That would be interesting. I'll watch for your post.

[gonjah]

That sounds about right. That's a big pool. I see why they had the sophisticated cleaning system now. If it works it would be nice.

[gonjah]

Actually, that sounds about right. As long as it clears up. If it's just settling to the bottom that's a problem though. I thought you were having difficulties. I'd still get your PH down and use some phosphate remover. I know the store will say 7.6 is fine but I've heard lower is better for chlorine to work effectively. At 7.4 I start pouring the acid. I shoot for 7.2 to 7.0. And keep my cholorine at as close to 5 ppm as possible. 10 ppm would not be acceptable unless it was *just* shocked. Even then that sounds really high but we use our pool.

[trader4]

What's a safety drain?

[Danny D.]

I probably am not using the proper term; but what I mean is the type of drain that I have on the wall which is not meant to be a primary drain; but is meant to merely prevent the main drain on the floor from creating suction enough to rip someone's bowels out were they to sit on the thing (were the cover to be removed).

This wall drain is situated near the main drain and it's sole purpose is to prevent the main drain from developing enough suction to be dangerous.

Googling, I find the September 28, 2011 spec here:

More information here:

"some state standards require that the water velocity through grates not exceed 1.5 feet per second (fps) with one drain 100 percent blocked."

The way I understand it is that, for safety reasons, you would want not only an unblockable main drain, but also a safety backup drain, so that, were the main drain to be blocked, it wouldn't develop full suction (due to the other drain on the wall picking up the slack).

I may be wrong though - as I do not present myself as a pool or pool safety expert.

[Danny D.]

For some reason, I'm no at all worried about 10 ppm chlorine.

I've googled in the past (not recently), and didn't find any real harm at those levels. There is absolutely no smell (although I realize that the so-called chlorine smell is from chloramines) and there are no side effects (e.g., bleached hair or clothing?) that we've ever noticed.

I like the chlorine level high - and I'm a bit unsure why others are so worried about it being high. Of course, "high" is relative to the CYA level. For example, the typical chart shows that, at, say, 100 ppm CYA, the target free chlorine is 12 ppm, and the shock free chlorine is 39ppm.

CYA MIN-FC TARGET-FC SHOCK-FC

20 2 3 10 30 2 4 12 40 3 5 16 50 4 6 20 60 5 7 24 70 5 8 28 80 6 9 31 90 7 10 35 100 7 12 39

So, depending on my cyanuric acid level (yes, I use trichlor in addition to bleach), 10 ppm could actually be low levels of chlorine.

But, before I go further, I need to have my CYA level tested again (I have three floaters filled with 6 tabs each at all times).

[Danny D.]

Hmmm... that actually depends ... on the CYA levels.

The *ratio* of the two is (apparently) what matters:

"the measured FC level should be at least 7.5 percent of the amount of CYA" "the target FC level should be at least 11.5 percent of the amount of CYA" "algae shock should be 40% of CYA; yellow algae shock 60% of CYA"

For example: If the CYA level is, say, 100 ppm, then the measured residual free chlorine should be at a bare minimum at 7.5 ppm; while the target would be 12 ppm; and the shock at 39 ppm; and the yellow algae kill at 58 ppm.

Now, 100 ppm CYA is rather high (I picked that for easy numbers); but the point is that the free chlorine, in and of itself, is not meaningful (in an outdoor pool) without also stating the CYA levels - because the ratio is what matters.

Having said that, I don't know what "my" CYA levels are, so, I need to have them tested so that I can determine appropriate minimum free chlorine levels; but I like to keep my free chlorine levels rather high and I see no (known) downside to high levels.

QUESTION: What are the perceived problems with high chlorine levels anyway?

[Danny D]

There are a lot of things wrong with the pool at the moment, but, at least the pumps are working great and not leaking! :)

a. The cleaning system water valve pistons are sticking b. The heating system solar panels are leaking c. The spa gas heater has a bad "fireman switch" d. The automatic pool cover motor isn't running etc.

So, I have plenty to work on ... :)

[gonjah]

I never check the levels right after a shock but I've never register any level above 7ppm. Probably is real high right after shocking.

I'd say anything above 5 ppm could cause skin irritation, eyes burning and maybe hair becoming brittle and washed out. You've heard of bleached out hair. I don't know how caustic it is to equipment but it could cause your gaskets and o-rings to wear out quicker. Breaking down the lube on fittings.

[trader4]

Again, you have not only the bottom drain, but 2 skimmers, for a total of 3 intakes.