New pool owner in trouble

Beamup

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LifeTime Supporter
Aug 28, 2010
176
Boston, MA
First things first, I suppose - current test results, as best I can get them.

FC: >5 ppm
TC: >5 ppm
pH: 7.8
TA: >500, though the folks who sold me the test kit said that this was unreliable if FC is >5. I suspect pH would be a lot more alkaline than 7.8 if this were true - am I correct?
CYA: My kit doesn't have it, and neither local pool store will test it with FC >5.
CH: As CYA.

And I did put this in my signature, but it's a 20k gallon in-ground gunite pool with a DE filter. Due to surrounding house and trees, it doesn't get a lot of sun - a few hours around noontime, mostly.

We bought our new house with a pool. We were told it had not been opened or the pump turned on for 3 years, but they opened and cleaned it up for our inspection. Seemed mostly fine, though there are some cracks at the waterline and it needed a new pump.

This season (our second), we started to see some greenish brown stuff on the walls and bottom (there was a very little bit of it last year, but not enough to make me think anything of it). The vacuum does nothing, a (nylon) brush will take it mostly up but "puff" it into the water. For reference, we just got back from a week-long vacation and by the time I'd brushed half of the pool the water was opaque green. I'm attaching a pic of our steps shortly after brushing today - the overall green tinge is the color of the water immediately after brushing when the previous brush was two days ago. The mottling is on the gunite. Even at its worst, it doesn't feel like anything when touched - just the gunite.

Being naive new pool owners, we went to the better-reputed of the local pool stores to ask for advice (mid July). They said it couldn't possibly be algae with chlorine levels that high (quoted at the time as "off the charts" which I'm guessing is >5 ppm since they use the same kit I have for in-store testing) and it must just be pollen (our lot backs up against some woods, mixed pine and oak for the most part). We were told to stop using powder and turn off the chlorinator for at least two weeks, then turn it back on at the lowest setting, so that the chlorine would drop to a proper level. Afterwards, the problem was much more widespread. They also said to run the pump 24 hours a day instead of the 8 recommended by the folks who installed it, which we've been doing since then.

Then we went to the second local pool store to see what they thought. These folks said it looked like algae to them, and on their advice we put two bottles of non-copper algaecide in (~50 oz). Didn't do much. Then they said we'd have to crank the chlorine levels way up; this month we've used most of a 40 pound bucket of chlorine tabs and a 24 pound case of powder. This also didn't do much.

Now the second store is saying that we'll have to, every day, use a bunch of "chlor away" to get the levels down to a testable range, then add a big pile of powder to get the level back up. Preferably twice a day for at least two weeks. A bit of pricing out suggested this would cost ~$150/day in chemicals.

At that point we concluded there must be a better way, started doing some research, ended up here, and read Pool School. I've just ordered a TF-100 XL and bought about 6 gallons of 6% bleach. Our intention is to follow the program in the "defeating algae" Pool School article once the kit arrives. (I'm assuming we need to get this under control before closing or it'll be completely berserk next season.)

So that's the situation. Now, the questions I have:

1. Does this sound more like algae or pollen?
2. Are we on the right track?
3. What sort of quantities of bleach should we be expecting to use?
4. Am I correct to be afraid that our CYA level is through the roof?
5. Any other tips or suggestions?

Any input will be greatly appreciated.

P.S. Due to the aforementioned cracks (and consequent loss of tiling), plus shifting of the surrounding deck due to dirt settling, we've been quoted $20k for draining the pool, fixing up the deck, replacing the tiles, and resurfacing the inside. This supposedly needs to be done in the next 5 years or so. I may be getting overly paranoid here, but I do assume this process will eliminate the algae (and by draining the pool, reset the chemistry esp. CYA). Should we be considering just closing the pool for the season, and doing that work beginning of next season? Or can the situation be salvaged with less drastic measures?
 

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Time to be patient. Once the test kit arrives, things will start moving quick. Once you get a full set of numbers, the path to a sparkling pool which will be the envy of all who see it will become clear.

That does look like algae to me. It can grow in vey high chlorine if the CYA is high. If the pool was maintained with pucks, it's not just likely the case - it's a near-certainty.
 
I agree with Richard. Odds are you have very high CYA. If you have any of the packaging for the powder or pucks you have been using look and see if it is dichlor, trichlor, or calcium hypochlorate. Dichlor and trichlor are stabilized (contain CYA) and calcium hypochlorate does not add CYA but does add significant amounts of calcium (CH). Both CYA and CH can only be corrected with reverse osmosis treatment or drain and refill. Reverse osmosis on a scale needed to treat a pool is only available in a few areas at this time, so the only way to fix the problem for most of us is drain and refill.

Go ahead and stock up on bleach, about 12 more jugs than you have now. The test kits usually arrive within a week so you won't be waiting too long. Once you are able to test the water and post the results we can help you decide whether you need to drain any water or not. Even if you decide you will do the needed repairs in the spring, you should go ahead and kill off the algae now. Many things can happen over a span of time to delay the repairs, and it is safer for you as a homeowner to be able to clearly see what is at the bottom of your pool even if you don't plan to swim in it for now.
 
Many thanks for the info. The pucks are trichlor, the power is Ca hypochlorate so it sounds like CYA will indeed be an issue. If it does turn out to be necessary, how is draining done? I couldn't drop the water by much before it goes below the skimmer and wouldn't reach the pump anymore. Do I need to hire somebody to come out with a big pump?

As you might have guessed, I've been kind of freaking out about this. The fact that those who know far more than I about it aren't, is very comforting.
 
Beamup said:
Many thanks for the info. The pucks are trichlor, the power is Ca hypochlorate so it sounds like CYA will indeed be an issue. If it does turn out to be necessary, how is draining done? I couldn't drop the water by much before it goes below the skimmer and wouldn't reach the pump anymore. Do I need to hire somebody to come out with a big pump?

As you might have guessed, I've been kind of freaking out about this. The fact that those who know far more than I about it aren't, is very comforting.
Emptying it is easy. You can rent or buy a small submersible pump, connect a garden hose, and go. You might be able to set your filter pump on waste setting and use it to drain things. If the yard is higher then the street, you could even possibly just siphon it out with a garden hose.

But you're getting ahead of yourself. If you get rain year round, things may not be so bad.
 
That photo is such a pretty clear green... makes me wonder if metals are involved. This is way above my pay grade, I know nothing about metals, but I'd like to throw that into the pot for the pros to consider, JIK. Knowing that the pool sat closed for long time, when it was opened, was there a particularly low pH?
 
Kit arrived today, here are the numbers:

FC: 21.5
CC: 0.5
TA: 130
CH: 520
CYA: 100 (the max reading on the tube, but the dot did disappear right there)
<EDIT>pH: 7.2 (forgot to list this at first, apologies)

So CH and CYA are high, but we're actually most of the way to shock range anyway (without any chlorine added since Saturday)! Of course, Earl's going to be hitting us tomorrow night so that's likely to affect things a bit. It doesn't seem like we could do anything tomorrow, but then we'd have the long weekend to work on shocking it.

Given that the FC is already that high, would it be practical to shock it from here without getting the CYA down? It'd only take a touch over 4 (1.42 gal, 6%) jugs to get it up to 39. Would the CYA consume FC faster, or just raise the needed level? Since a large chunk of water gets taken out at closing anyway, it seems like if we could just get this done we could live with the CYA for the rest of the season (less than a month).

Also attaching a current pic, again of the steps area, for reference.
 

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CYA doesn't consume chlorine. It just binds to it.

But to answer the pressing question... yes you can try shocking with that high CYA. 4 gallons may take you to shock level, but it's going to take a lot of bleach to keep it up there. Shocking is not a one-time thing. As soon as you add some, it's going to start being used up killing algae, so you'll need to keep replenishing it every couple hours.
 
You'll be best served by a partial drain and fill to reduce CYA and then start the shocking process. Also, Given the FC of 21, chances are your PH is actually lower than 7.2. Shocking with CYA at 100 is VERY difficult. Shock level for 100 is an FC of 39+ Given you are at 21, you won;t be making much progress if that is algae.
 

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Storm coming? How much rain are they suggesting you might get?

First, let me say I AM A NOVICE -- let's run this idea past a few pros.....Use the storm to do some of your drain and fill.

Drain out some water, not too early since you will probably have issues when you get to the bottom of the skimmers. Then I'd shut it off. Do this as close to the storm hitting as possible, not too early as you'll just sit too long without circulation, not too late or you will lose power before you get much water out. I'd take out enough to get to the bottom of the skimmers, or 4" if I could manage it, maybe more depending on what rainfall they predict. You have lots of FC to carry you through. The rain will drive the pH up, so forget about that for now.

Now an expert may say to do differently, so let's get that advice from them. If you are out of power for a long time, you will be set way back anyhow with the algae that is in the pool. You may have a lot of debris in the pool after the storm. You may need to do a big drain and fill then anyhow, just to get the black water out if you get trees and such in the pool.

But, sometimes 30 miles is as good as a miss with hurricanes. You may get nothing but some wind, or just some rain, or nothing, or the whole thing. Those storms are so tricky.
 
They're currently suggesting that Earl's only going to hit us with 2-4" of rain due to a recent move further offshore. And the water's already almost low enough to make me add more, so I don't think I'll get far by counting on the storm to do much. But I'll retest Saturday morning and see what happened.
 
As it turned out, Earl was mostly a non-event for us. Rechecked the CYA this morning and got 100 again. Then I went ahead with trying to shock at that level. Here are the FC/CC results so far today:

7:00 - 24.5/0.5. Added 5 1.42-gal jugs of 6%, vacuumed the debris from the storm, and brushed everything.
8:00 - 40.5/1.5
9:00 - 42.5/1.0
10:00 - 42.0/1.0
11:00 - 42.0/1.0
12:00 - brush again
1:00 - 44.5/1.0

So accounting for the uncertainty in the test (10% per Pool School) it looks like we're holding nicely above shock level, with modest but not huge CCs. The water is a bit cloudy, but not as bad as it normally is right after I brush (can't quite make out the bottom drain from the side). There was a distinct bleachy smell around 8:00, which I'm guessing was the CCs, but I can't pick anything up now.

This is not what I was expecting - from the writeup in Pool School, I'd anticipated having to add more bleach every hour or two, not go 6+ hours without a detectable drop in the FC level. Is this normal? Does it suggest something's wrong?

BTW, if at any point this should move to the Algae forum just let me know - I'm happy to start a new thread there if appropriate.

And I'll check the tap water CH shortly. EDIT: It's at 60. I guess the CH in the pool is from all the cal-hypo.
 
IMHO you are fighting a losing battle with your CYA that high - I'd continue with partial drains/refills to lower the CYA level. You can continue shocking at this time if you want, but really the high CYA is going to complicate things. On the flipside, the high CYA is also helping you hold shock level during the day, it is normal for your situation and doesn't suggest anything is "wrong"...
 
What exactly will it do to complicate things? Take longer to kill off the algae, or something like that?

I really am grateful for the input - all the people here are so helpful, it's great! And it's much appreciated.
 
So, an updated status report. I've been keeping the FC levels around 50 (CC never above 1.5), and have only needed to add 3 jugs in 2 days to do so, and brushing twice a day. The water's clear (but then it always was, unless I just brushed), but I can't really tell if anything is happening to the stuff on the walls - its appearance just varied too much depending on brushing.
 
The pool has passed the overnight FC loss test three days in a row now*, CCs are barely detectable and the water's always been clear. So I guess the shock is done. The walls and floor still have some brown that doesn't respond to brushing and hasn't changed noticeably, though. Staining, I guess?

*: There's actually been no detectable decrease in FC in the past three days, except for when a biggish storm blew a bunch of grass and leaves in.
 
If I am seeing the pictures correctly, you have a pool with copper sulfite staining and scale. The green coloration looks to me like someone used a copper algaecide or the pH got too low and etched copper in your system. The brownish areas are scale build up from hard water. The pool looks like it has had years of neglect prior to you getting it. I would work on getting your CYA levels down so that you can minimize your chlorine level and do the best with what you have for now.

The pool looks pretty rough, and I think you are on the right track with looking forward to some remodel (replaster, tile, etc.) work. Draining, tiling and replaster around here would run around $7-8K, assuming some sizing on your pool. Unless you have a large amount of decking, the price sounds high to me. Check around before you commit!
 

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