Newbie with a Green Pool

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FresnoPoolDad

FresnoPoolDad

0
Aug 11, 2012
18
Fresno, CA
Hi folks. My pool started to turn green Wednesday and is full green today. My marriage may depend on this as my wife has a party planned for Thursday so any help would be appreciated.

As background, I live in Fresno. Temp has been 105-110 for the past few days. Its 107 today and forecasted to drop to a cool 100 by the end of the week. I moved into the house three years ago. The first year I tried to handle the pool myself with the help of my local pool supply store. I ended up with an algae problem that I treated with algaecide. It would go away for a few weeks and then come back (I might have let the Chlorine levels drop). I treated with Algaecide again. I think this happened three times before winter. In the spring, I hired a pool service. They told me that I had "killed the water" with the result that it would not hold chlorine (not sure what they meant but after reading on this site I am guessing that my CYA was too high) and that the pool needed to be drained. We drained the pool and started over. I also replaced my cartridge filter and purchased a new Hayward vac.

The pool service has handled the chemicals since the refill. We did not have an algae problem for the first year and a half. My wife noticed the pool going a bit green on Wednesday. As I couldn't find any evidence that the pool service had come, I thought that maybe the chlorine was low but I wasn't smart enough to bring in a water sample for testing. I put two 10 oz packages of Genesis shock (fast dissolving trichlor) Thursday morning hoping to hold off the algae and called the pool service (I realize after reading here that this was probably a mistake). As I said, the pool service came out Friday but the pool got even greener.

On Saturday, I found this site and, after doing some reading, ordered a TF100 test kit but this won't arrive for a few more days. I also read the very helpful sticky on defeating algae. I dumped 2 x 96 oz of 6% bleach in the pool yesterday afternoon. This morning I purchased a basic OTA test kit from the pool store and had them test the water (not ideal but it will have to do until the TF100 gets here).

FC - 5
CC - 5
pH – 8
TA - 90
CH - 200
CYA – 99

If I understand the CYA/Bleach table my target FC is 12 and my shock is 39 so I am well below shock amounts.

I am not sure how to proceed at this point and have some questions.

(1) I do not understand why the CYA is so high given that the pool was drained just last year. Its really weird to me but I do not know what the pool service has been dumping in there. I read on this site that genesis raises CYA so maybe that is why but I haven't put that much in. Does the CYA go down overtime naturally? Also the guy at the pool store said that 99 was an okay CYA number but that doesn't sound right. Does recommended CYA vary by region.

(2) Do I need to try to drain some water to bring CYA down and if so how much water do I need to drain.

(3) The pool calculator says that I need to add 5 x 96 oz of bleach! Can that be right?

(4) Is there anything that I can do to clear the problem so that my wife can have her pool party? If not, do any of you have room on your couch for a few days? :wink:

Thanks in advance for your advice.
 
Yes, CYA of 90 is high, you want to shoot for 50. I would do a water change of about 40-45% and get the CYA down. Once the pool is refilled I would adjust PH and start the shock process as described in pool school. This is going to be difficult w/o a test kit on hand. You can shock the pool without changing the water but it is going to mean using twice as much chlorine to accomplish the same thing. With a CYA of 90, you will need to maintain a FC level of 35ppm to shock the pool. If your CYA was 50, you would only need to keep it at 20ppm. Start stocking up on chlorine, you are going to need it. I'd start with about (20) 182oz bottles. CYA only generally goes down as we splash it out of the pool and replace the water.
 
1. CYA does not go away without removing and replacing water. CYA does not really vary by region. Pool stores just do not typically understand the CYA/FC relationship.

2. You likely need to replace over half the water

3. That might get you started, but you will need much more to finish the process.

4. Doubtful. The shock process can take up to a few weeks depending on how diligent you are and what is going on in the water. Also hard to do without a kit.


Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Thanks for the responses. I wish I knew what pushed the CYA up. I am not sure what the pool service was using to chlorinate but it was probably liquid Chlorine as he brings it in a 10-15 gal. tank.

My plan:

1. Drain the pool and refill
2. Have the pool store retest the water
3. Adjust pH
4. Begin shock process as described in the pool school.
5. Report back to you all.

What the addition of an Algaecide speed things along in addition to the draining and shock? And if so, do I need to modify the process? I read in the sticky that algaecides rarely help so maybe I am grasping at straws but I am still hoping that my wife can have her party.

Thank you!
 
no point to spending money on algaecide ... such to liquid chlorine.

Also you must have a good test kit to correctly perform the shock process. Pool stores testing is notoriously inaccurate.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
Welcome to tfp, FresnoPoolDad :wave:

Are you sure you cya should be high? Pool store testing for this can be very unreliable.

If you have been using trichlor pucks or dichlor powder, then it very well could be.

Since you have ordered a tf-100, I might wait until that comes before doing a drain/refill..just to be sure of the amount you need to do.
 
The TF-100 shipped this morning so I should have it sometime mid-week. I think I might drain it anyway if I can figure out how to do it myself. The pool store test put me at 99 CYA, even if they were off by 20% I'd still have a CYA of 80 which, if I have understood what I read, would still be too high.

In the meantime I have a CYA question. If CYA only goes away through water loss via splashing why do pucks and dichlor put it in there at all? It seems like using this stuff will inevitably kill your water. I read on here that the Genesis shock that I used a few times raises CYA 4.4 ppm a pack. If CYA never goes away and you start with a CYA of 50, wouldn't that mean that you could shock with the product at most 10 times for the life of the water? Also since more CYA means that you have to spend more $ on a weekly basis for chemicals, doesn't that mean each time you use it the price of maintaining your pool goes up?
 
You are absolutely correct and that is the reason we do not recommend using any solid forms of chlorine.

Cal-hypo is another form of solid chlorine, but it adds calcium. If your calcium gets too high, that can lead to other problems like scaling on the walls.

You think maybe some of the pool industry knows this ... sells the pucks ... eventually the pool turns green due to high CYA ... so they sell you some "shock" which may also raise the CYA ... sells you some phosphate remover and algaecide ... pools stays green .... then recommend you replace the water after making a few $$$$ off you ... and then sell you some more chemicals to "start up" you new water and start the process over?
 
The pool guy is here now. He says that they RAISE CYA to 100 which the consider normal and that no pool in Fresno would "hold chlorine" at CYA 0f 50 because of the heat. He claims this is the recommendation of IPSA whatever that is? Is he nuts?
 

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The only reason to have the CYA that high would be if you are trying to only maintain the pool once per week ... even then it is a challenge. Pool services do not want to have to visit every pool everyday ... they would not make money. So they use alternative techniques to try to keep the pool clear ... like raising the CYA high and then dosing the FC up near shock level and hoping it does not drop too low by the next time they show up.

We recommend testing your pool daily and adding the FC as required daily ... this allow you to maintain a consistent and acceptable FC level with no chance of algae starting.

The real problem with a high CYA is IF/WHEN the pool turns green ... the shock FC level is VERY high. Additionally if the normal minimum FC level is > than 10ppm (see poolcalculator or the chart), the pH test is not valid ... so it becomes difficult to maintain.
 
FresnoPoolDad said:
The pool guy is here now. He says that they RAISE CYA to 100 which the consider normal and that no pool in Fresno would "hold chlorine" at CYA 0f 50 because of the heat. He claims this is the recommendation of IPSA whatever that is? Is he nuts?
Click to expand...

I'm going to let others from areas of the country like that chime in - but my opinion is that he is misinformed. It's true that a CYA of 100 will hold FC longer than a CYA of 50 - that's one reason that the Salt Water Chlorine Generator CYA recommendations are different.

But many people in Texas, Phoenix, etc all participate here and have great pools with much lower CYA levels. The problem isn't maintaining - it's fixing problems. Shocking at your level is expensive and labor intensive vs. doing it at half the CYA.

One thing - you reported a CYA of 99 - the tests are generally not very accurate around 100 CYA and many stop reporting accurately over that value. You might want to do two things before the TF100 kit arrives. First - take a sample to a different store - get their results. Second dilute a sample with tap water or distilled water and have them test it - double the CYA result from that test.

If they started you at 100 CYA and kept tossing in pucks and shock - you can't still be as low as 100...
 
Did you see him test the CYA? How did he do it? On most tests anything above 100ppm shows up as 100ppm. It would certainly be advisable to get your CYA in range before proceeding with the shock process.

While the filter is required to clear the pool once the algae is dead, it will not stop an algae bloom without a lot more chlorine than 5ppm ... review:
Defeating Algae
Turning Your Green Swamp Back into a Sparkling Oasis
Shocking Your Pool
 
FresnoPoolDad said:
He just tested and claims that it is at 100. He does not want to shock because he claims that shock won't h elp. He blames filtration. My filter was sucking air at a valve. now that the leak is fixed, he claims that fc of 5 will clear out up.
Click to expand...

If they started you at 100 and it is not a liquid chlorine or SWGC based pool then it can't stay at 100. The test tends to top out at 100. Have him test again with 50/50 pool water and tap water and see what the level is. If that shows 100 - do another test at 1/3rd pool water 2/3 rds tap water to see what that shows.

Honestly - you can handle the pool without him and his advice cheaper and with fewer issues.
 
It sounds like this pool service runs their CYA at 100 and it is not unheard of. Since they seem to use liquid chlorine the 100 number is probably fairly accurate, but most testing equipment has no way to verify it above 100. This is why the mixing of 50% pool water and 50% of tap water is recommended to give you an idea if it is close to 100.

With your pool service blaming the algae on your equipment it shows me that they are completely lying to you about the cause of the algae, or they just don't have a clue as to what caused the algae. The plain and simple reason that your pool bloomed of algae is that your FC, "free chlorine level", was too low for the CYA level. If you follow the guidelines in the FC/CYA chart, pool-school/chlorine_cya_chart_shock, your pool will stay algae free.

He doesn't want to shock the pool because he knows it is very expensive and time consuming to shock a pool with a CYA of 100. He will have to use liquid and be there daily to fix the water. Come winter time the algae might get cleared, but I doubt it.

I recommend reading Pool School and waiting for your test kit and then take control of your pool by getting rid of the service. As for the pool party, sorry I can't help you there, but the people here at TFP will most certainly help you and me as best they can.
 
Thanks! The pool company does run their service at CYA 100. He told me that they deliberately brought it up to 100 as soon as I refilled it. I think he was definitely lying to me about some things. The service only comes every other week, which makes me think that maybe the run CYA so high so that the Chlorine will stick between service. I definitely do not trust him. I'll run the CYA test at 50% dilution as you recommend once my kit gets here.

In the mean time, my pool is completely clear. He put some DE in the filter (via the skimmer). Then he put in a metal algaecide and a clarifying agent of some kind -- all without asking me by the way. But the pool was completely clear 4 hours later! My vac has even sucked all the green off the walls and floor. I brushed the walls and steps anyway and will change my filter Wednesday. It looks like he bought me some time for my test kit to arrive.

I have another question. Two years ago when I was handling the pool myself I got into a situation where I couldn't keep FC up no matter how much Chlorine I put in. I would add a ton of powdered chlorine (not sure what exactly but I think it was Leslie's Calcium Hypochlorite) bringing the level up to 7 one day but it would be back down to zero the next. This happened repeatedly to the point where I bought a new OTA test kit because I thought maybe the reagents had gone bad. But I had the same problem. That is when I called in the pool service. They told me that I had "killed" the water. Any idea what may have been the problem? I thought maybe that I had a CYA that was too high but now I am confused.
 
FresnoPoolDad said:
They told me that I had "killed" the water.
Click to expand...
What did they do to fix this "dead" water? :lol:

FresnoPoolDad said:
Any idea what may have been the problem? I thought maybe that I had a CYA that was too high but now I am confused.
Click to expand...
It could have been high cya, requiring higher FC levels that you may not have adjusted for, therefore allowing algae to grow. It could have been low cya, causing most of your chlorine to be lost to the sun. It could have just been algae due to your FC getting to low at some point.

Good news is, with your test kit, you can know what is wrong and how to fix it. You can also get rid of the pool service.
 
The didn't fix the "dead" water exactly. They drained it completely and refilled it.

It could have been high cya, requiring higher FC levels that you may not have adjusted for
Click to expand...
If I had a high cya wouldn't that cause my FC to stick longer once I got it up? I guess it doesn't really matter. The point now is that I'll have a kit soon and can figure out what is going on for myself.

I realized that I missed some of the post above which now that I read them make a lot of sense. First, I am pretty sure he was lying to me about quite a bit. I am skeptical that he actually tested the pool. I really which that I had my test kit so that I could have called him out. I asked him about what products they use and their method. They use liquid but not exclusively. They also use Calcium Hypochlorite and pucks willie nillie. Their strategy is exactly as jblizzle says -- they come once every two weeks at which time the raise the FC to 10 and hope that it holds for two weeks. That must be the reason for the CYA of 100. I am guessing that the heat gave the algae a boost just when the FC fell and bam I am in the dog house.
 
FresnoPoolDad said:
If I had a high cya wouldn't that cause my FC to stick longer once I got it up?
Click to expand...
It may protect it better from the sun, but you also need to maintain a higher FC to stay algae free. See: http://www.troublefreepool.com/pool-school/chlorine_cya_chart_shock That is why we recommend 30-50 ppm cya for non-swg pools. It is enough to protect some from the sun, but not so much you need extreme FC levels to stay algae free (or really high FC levels when shocking).

FresnoPoolDad said:
The didn't fix the "dead" water exactly. They drained it completely and refilled it.
Click to expand...
I would guess you had high cya then...this is the most common reason to drain and refill.
 

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