Struggling To Get Pool Balanced

Ken

Member
Jun 13, 2007
5
Hello All!

A little history...pool came with the house when we bought. It's a 25,000 gal plain old plaster in ground pool. We recently replaced the pump/filter from DE system to a Cartridge system (4 filters/1.5 horse motor). We've never had any problems keeping the pool algae free and in balance until this year. In the past if algae became present, on the recomendation from the pool folks they'd adivse Yellow Out or Green Out with shock. It always cleared up.

Well this year for past 1 1/2 months, we've been struggling to get rid of the algae and get in balance. I've spent well over $500.00 in chemicals...to no avail. I'm at my wits end and now refuse to listed to anything the pool people tell me. It finally came to a head this past weekend. Upon returning, the pool was covered in green algae all over the walls of the pool, hovever the water was crystal clear. On the pool stores advice, they told me to shock the pool with 6 bags of shock (tricholor based) and I can't remember the brand (I also shocked the pool on friday with the same shock). I also brushed down all the sides of the pool. Tuesday morning the pool looks worse than it did Monday. No more pool store advice!

Following some other things i've read, I shocked the pool Tuesday night with 7 gallons of plain old regular strength Clorox. I brought the pool store a sample to be tested this morning and here are the results:

FAC = 4
PH = 7.2
TA = 110
Calcium Hardness = 400
CYA = 100
TDS = 950

Am I on the right track?

Also, can anyone suggest a good test kit to buy...I want rid my self of having to travel to the pool store!!!
 

duraleigh

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Apr 1, 2007
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Sebring, Florida
Also, can anyone suggest a good test kit to buy...I want rid my self of having to travel to the pool store!!!
Hi, Ken,

What a lead-in....check the link in my sig below :lol: :lol:

I see two things in your numbers:

1. You put in enough bleach to go to 17ppm plus whatever was in there and the next morning you had 4ppm. You've got bugs (algae) in your water that need to be killed.

2. With the CYA @ 100ppm, you're gonna need to go to at least 25-30ppm to start clearing your pool. That Cl will start to drop instantly and the very next time you test (hopefully within hours, you should put in enough bleach to bring it back up to 25ppm again, at least.

The methods used here on the forum work to perfection but probably the least understood is the most important....it takes high doses of Chlorine, APPLIED IN A MANNER TO MAINTAIN THAT HIGH DOSE, over an extended period of time. The bugs (algae) will eat your Chlorine quickly so you have to constantly replenish it until your water clears.

Since you can't test to those high levels of chlorine, you'll have to go back to the pool store a few more times. (Try not to buy anything...bleach is the only thing you need.) Each time they test, you MUST bring the Chlorine back up to the 25ppm range until your pool is sparkling. "bleachcalc" is available on the forum....download it to do the math.

Stick with the advice here.....you'll get a crystal pool at little cost...promise
 

Ken

Member
Jun 13, 2007
5
Wow, thanks for the quick response!

So, should I dump another 7 gallons of Clorox? And when I bring the sample to the pool store, they should test all levels...right? FAC, TAC...etc.
 

duraleigh

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Ken said:
Wow, thanks for the quick response!

So, should I dump another 7 gallons of Clorox? And when I bring the sample to the pool store, they should test all levels...right? FAC, TAC...etc.
Well, yes and no. You should put in enough to bring your Cl to 25ppm....(make sure you're counting gallons and not ,75 jugs.) If you have zero CL now thats a little over 10 gallons. Do you have any type of chlorine tester?

Secondly, yes, if they will give you results for free chlorine and combined chloramines, that's really all you need. Your other chemistry is okay and can be fine tuned later.

You will find this a great forum with a lot of folks smarter than me very willing to help you clear your pool....stay with it. :lol:
 

Ken

Member
Jun 13, 2007
5
Ok here's the latest results as of this morning. I'm still waiting for the Taylor test kit so the FAC i'm not sure is accurate.

FAC = 7.0
PH = 7.2
TA = 120
Calcium Hardness = 400
CYA = 100
TDS = 1200

Pool is crystal clear....nice and blue! However, I can still see what looks like algae on the walls and floor (really light in color, but you can see it). I've tried to brush off but it won't come off, it's as if almost the algae left a stain. Can that be possible??

Also, i've been draining water from the pool in hopes of brining down the CYA leve. Is that the only thing I can do to bring down that level?

For anyone who reads this...Clorox is the way to go!!! Use the BleachCalc and you can't go wrong!!

Thanks again for any help!!
 

chem geek

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Mar 28, 2007
12,083
San Rafael, CA USA
Furthermore, you got into this situation because you were using a source of chlorine that contains CYA in it -- probably Trichlor tablets/pucks. When you had your DE filter, you regularly backwashed and that helped to dilute the water to keep the CYA levels lower. Since you've switched to a cartridge filter, the CYA levels have climbed more rapidly and you haven't increased the FC level accordingly to keep a minimum FC of 7.5% (target 11%) of the CYA level (i.e. you probably had the FC below 7.5 ppm at your 100 ppm CYA).

Though you can certainly battle the algae with high levels of FC at this point, you are still going to have to address the CYA issue so you might consider doing a partial drain/refill to dilute the CYA level in half and then do your full battle with the algae at that point since it will take about half as much chlorine to do so. Perhaps doing a continuous dilution while battling this algae would accomplish two things at once.

After you've gotten rid of this algae, you will need to switch to another source of chlorine, such as bleach or chlorinating liquid, as your primary source and only use the Trichlor when your CYA level is low and you want to add more. You will have to add the chlorine every day to the pool unless you get a pool cover to keep the sunlight UV out of the pool.

Richard
 

Ken

Member
Jun 13, 2007
5
Thanks for the advice!

The pool has been maintaining between 5 - 7 FC since i went through this whole ordeal. Water is nice and crystal clear but i still have the algea stains that i've been try to scrub of to no avail.

I just received my new taylor test kit but i'm unsure how to test with the new kit. I tried yesterday but i must be doing something wrong when i tried to test for the FC level...the pink color would not turn to clear even after 110 drops of the re-agent. Can you give me any assitance, is there an easier way using this kit?
 

algaeh8er

Well-known member
Jun 11, 2007
92
NorCal
I just got the Taylor kit this week. Are you testing a 10 ml or 25 ml sample? With the 25 ml sample, you are counting in .2 ppm increments for each drop vs. .5 with the smaller sample. This still doesn't account for your numbers if you think your FC is in the 5-7 ppm range, but it would account for it if your FC is above 20.