High CYA, Low Chlorine, Algea Stains... Now what?

Jun 13, 2012
15
#1
Help!
Not knowing anything about pools - and traveling 3 out of 4 months - got me in a bind.
We bought a house with a pool and happily let the TC pucks float in the floaty, but not long ago a lot of the dirt after a sand storm didn't want to be vacuumed. Then we found that brushing didn't do anything for it either and it kept growing.
Started in the curves on the shady side, but spread all over.
I thought it was iron, but Vitamin-C didn't touch it and the Tc puck made it disappear.
I needed to do a partial drain anyway because my CYA levels were way off the charts - 3.5ml pool water and 3.5ml of the CYA reagent cut with 7ml of distilled water got me to a CYA reading of 60. My limited math skills tell me that my CYA is approximately a whole bunch.
So... Where we are now:
I drained 3/4 of the water from the pool and added a couple of gallons of 6% chlorine bleach to what was left, then we washed the walls with a strong bleach solution. Walls look real good now - though the paint is kinda' uneven in spots - but the stains on the floor weren't budging.
I tested and came up with 30ppm FC and added another gallon of bleach. That's about when the water started turning cloudy.
At this point the water - about 2' deep - looks like skimmed milk. When I hit the floor with a brush I get rolling clouds of white broiling in front of the brush. The stains seem to have faded some, but the worst ones, the ones at the curve between wall and floor on the shady side, are still very prominent. I can't tell what the stains down by the drain are doing 'cause I can only see through about 6" of this stuff.
Any ideas, guidance, suggestions...?
It's been soaking like this for about 4 hours in 110 degree full sun.
Appreciate any help.
Jak
 

duraleigh

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#2
It is very hard to say exactly what that is but a lot of what you are describing makes me think it is mustard algae. Since your pool sounds like it is 2/3 drained I see nothing else for you to do but completely drain the pool and refill.

Muck it out good and get everything out you can and then refill. Don't expect your problems to be over because the algae will bloom right back just as soon as you lose control again.

Once it is full, if you can post a complete set of test results, I think we can guide you through a shock process that will get rid of MOST (but probably not all) of your issues.
 
Jun 13, 2012
15
#3
Dave,
Draining the rest of the way would be an expensive proposition.
My thinking on it was that by taking it down 3/4 I'd be able to raise the chlorine level in the remainder enough to deal with the stain and jump-start the chemistry for the refill.
Is that just wishful thinking?
My only concerns right now are why the water turned white and cloudy, and whether this is going to do the job of killing the algae.
If I can avoid having to rent the pump and hoses again, I'd like to.
I tried pumping it down some with the pool's own pump, but I guess it's too far for my 1-1/2 horse pump to handle.
Jak
 

JasonLion

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#4
JakHammer said:
Is that just wishful thinking?
Yes.

Your current procedure doesn't give you any control over what is happening, nor will it kill all of the algae. It will kill a great deal of algae, but never get it all. As duraleigh said, the chances are excellent that you will simply get algae again the moment you refill the pool.

The milkiness is calcium clouding. It will go away once you get the pool refilled and your levels balanced.
 
Jun 13, 2012
15
#7
OK guys,
I've refilled the pool after a 75% drain and Clorox scrub to reduce CYA and clean up algae stains.
I had some trouble getting the pump to prime, but finally got it going about 1:00 this afternoon and plan to let it run through the night.
The water looks great. There was a lot of calcium sediment on the bottom that I did my best to get vacuumed up and discarded through a hose outlet between my pump and filter, but I'm sure a lot of it is in the filter being dissolved back into the water.
Water temp is about 85 degrees and crystal clear now as the sun is setting.
Here are my numbers:
FC = 6.8 ppm
CC = 0.0
PH = 7.5
TA = 80
CH = 950? (I'm not sure about this test. The sample went from Red to Clear at about 53 drops then a pale blue by 95.)
CYA looks to be a little under 30

I plan to test again first thing in the morning to see if I get chlorine loss overnight.
So, where should I hold chlorine levels, and for how long, to be sure this algae issue is as under control as possible?
I found a pile of mud and who-knows-what in the light well. Glad to get that cleaned out.
One minor complication is that there are two simple fountains on the pool and I am a little concerned about what might be in their pipes.
I washed them good with chlorine and let it backwash down their pipes as best I could. We rarely turn them on, but I'm letting them run now and will plan to run them for a couple of hours every day if that makes sense.
How anxious do I need to be about getting CYA up a little? I still have a big bucket full of Tri-Chlor tabs that I'm happy to use up.
We're going to be away for a week coming up and the pool will have to go on auto-pilot for that time, so I need to get everything lined out before that. Then I work out of town a lot and my wife's not much into pool maintenance so I need to get the process set and streamlined to make it as easy as possible for her.
Any suggestions now or shall we wait and see what the numbers look like in the morning?
Jak
 

duraleigh

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#8
I would do my best to get the calcium out of the pool first. Your test results are puzzling and I would suggest you do it again. Use a 10ml sample this time and modify your procedures by reading "extended test kit instruction" so that each drop will count as 25ppm. Post back if you can't locate those directions here with a search.

Once you get a more reliable reading, post that back and let's see if you need to do anything about it or can let it ride.

Have your tested your source water for CH? Report that also.
 
Jun 13, 2012
15
#9
I retested today - wasn't able to do the overnight loss test - but here's what I came up with around Noon:
FC = 5.6
CC = 0.0
PH = 7.5
TA = 70
CH = 650 - 750 -- Then I tested the tap water and came up with 375 to 425 -- then tested the pool water again and came up with 500 to 625. I give a range because it is not clear to me when the color is what we're looking for.
It seems like the various chemicals never thoroughly mix with the water so rather than having clear, colored water, I get water with fine colored drops floating throughout. When it transitions from pink, the droplets turn a pale purplish color and then fade out all together before taking on a blueish tinge. I did the last tests indoors and it was easier to see the colors without the harsh sunlight.
The range I am posting is based on the drop count where it changes from Red to Purple and then from Purple to Blue, so the higher number is probably the more accurate.
Is there a trick to this test, or just experience needed?
Is there likely to be some other chemical interfering with the test?
I looked back at the test reports from Leslie's and they never gave us a Calcium Hardness, just a Total Dissolved Solids.
Assuming my CH is around 650, how big a problem is that, and what can I do about it?
I know there are some Calcium sequesterants, but is there a way to actually remove calcium from the pool?
Jak
 

JasonLion

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#10
There will often be small specs, "floaters", in the sample when doing the CH test. Ignore the floaters and concentrate on the color of the liquid in the sample.

Having the sample go purple is a floating end point, which will result in false high results. Try the suggestions in the extended test kit directions of avoiding a floating end point. The end result you want is something in the blue family. It doesn't matter what blue in particular, just that additional drops don't change the color any further.

You can live with CH around 700, but it takes extra attention to maintain the PH and TA at appropriately low levels to compensate. Given your description, I rather doubt that your CH level is nearly that high.
 
Jun 13, 2012
15
#12
OK, I had missed the directions for my problem.
It still turned purple first, but then went distinctly blue at about 23 drops. I added several more drops and am sure I didn't get a color change after 24.
Multiplying by 25 puts the CH at 575 - 600 +/- 10%. That seems a little more reasonable. I'm guessing that the tile scraping we were doing while the pool was filling didn't do us any favors on the CH front.
So that puts my latest numbers at:
FC = 5.6
CC = 0.0
PH = 7.5
TA = 70
CH = 600
CYA not registering.
I threw some Tri-Chlor pucks in the floaty to try and keep FC from dropping to 0 by sunset with the full AZ sun shining on it.
So, where do we go from here?
Jak
 

duraleigh

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#13
You will need to purchase some CYA but tell us what your water looks like first. Do you still have visible junk/powder on the bottom?
 
Jun 13, 2012
15
#14
No. The pool looks spectacular!
If I knew how, I'd post a picture.
It looked good yesterday evening, but I let the pump and vac run overnight and it was really beautiful this morning.
There was a lot of sediment when we finally got it filled and I got the pump sucking. I wanted to divert the initial vacuum water out before the filter - and did as much as possible - but the flow through the pump was too strong to divert it all. I had to open up some of the returns to keep the pump running free, so I don't know how much of the sediment I actually got out through the hose and how much is in the filters.
I wanted to wash the filters today, but just haven't had the time. Might make a few minutes to get that done yet.
Jak
 

duraleigh

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#15
So where do we go from here?
1. Clean your filters....sooner rather than later. Has your psi gone up much?

2. Purchase enough CYA to get your pool to 50ppm and put it in your pool

3. Keep your chlorine around 4-6ppm using bleach.

4. Go swimming
 
Jun 13, 2012
15
#19
Let's try pictures.
Here's the pool after we drained most of the water and were getting started on cleanup.


And here it is the day after we finally got it filled and ran the pump all night.


I have a sock full of CYA floating near a jet and will bring it slooowwwllly up to around 50ppm.
Want to leave room for the occasional Tri-Chlor puck when we're out of town.

Here's something else.
I had thought this thing was disconnected, but it was hard-wired into my timer and plumbed with a little hose to the back of the pump intake.
Suggestions?


Thanks for all of the help.
Jak