Green Algae for over 8 weeks

Jul 10, 2011
3
mis amigos,

I should have found this site a year ago when I got a house with a pool... this is a great site...

I live in Davie, South Florida and have been maintaining my pool with rookie knowledge for over a year. I was using dichlor powder (rookie mistake) for regular maintencnace. recently, I got hit with green algae which has not ogne away for 8 weeks. I went thru all the basics and algae prevention (Defeating Algae) posts on this website.

I am using aAqua Chem 6-way test strip and I agree I need to get one of the other sophisticed test kits. Based on the test stirp these are my results:

Hardness 1000
Total CL 0
FC 0
PH 7.2
Alkalnity 180
Stabilizer 150 (This is the max the test can find).

I took the sample to a pool place and they also could not test CYA > 100.

So the problem is high CYA, so I drained my pool in half and refilled, the new readings are:

Hardness 250
Total CL 0
FC 0
PH 7.2
Alkalnity 120
Stabilizer 150

Looks like I have a real issue with CYA. I put in 4x2.5 jugs of 10% chlorine and after an hour the readings are as follows: (Max identifies the max reading the test strip provides)

Hardness 250
Total CL 10 (Max)
FC 10 (max)
PH 7.8
Alkalnity 40
Stabilizer 150 (Max)


Things I know:

- My CYA is toooooo high

Questions I have:

How do I take control over my pool, some questions I have:

1. Should I use Aqua Ammonia to kill Algae at this high levels of CYA? What are the disadvantages? One article from Jasoc mentioned the do not recommend this because of 2-reasons. What are those?

or

2. Should I drain the pool completely? And refill water, so that I have the CYA in check?

I can be reached at 786-208-9836.

Thanks in advance.
 

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  • 2011 July Algae Readings.xls
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You're probably not gonna want to hear this since you just drained it halfway.................but I'd dump it again ( the most I absolutely could)..............and start over again. Your cya level is still most likely over 150. Everything is easier to maintain and fix at more normal CYA levels. Plain old bleach will kill your algae and sanitize your water on a regular basis. See shocking your pool and the cya/chlorine charts in pool school. Welcome.
 
At this point, I think you have two priorities. Lower your CYA and get a good test kit.

The CYA can only be lowered by partial drains/refills or by reverse osmosis. Assuming reverse osmosis is not an option, I would drain about half the water and refill.

I would also order a tf100 test kit from tftestkits.net.

While you're waiting for that to arrive, read pool school as often as possible, so you're ready to hit it hard when the test kit arrives.

No need to put anything into the water other than bleach or liquid chlorine until you're through the shocking process. Your ph looks ok.
 
I believe that chlorine won't help much. Best answer is to do the drain and refill dance. Not sure how deeply you can drain the pool without damage, local experts may know. Half is safe, alot more than that needs info on pool type. It would be best to try to do it on one step to minimize wasted water.
Try diluting a sample of pool water with tap water, then test that for CYA. Have one sample 50/50, another 75tap/25pool.
Sometimes pools with high CYA will find extra CYA shows up after draining, apparently from piping, really unknown. So shoot for a lower CYA, just in case, like 30. After a week our so, when any mystery sources of it have released, you can raise it in measured amounts.
 
woodyp said:
You're probably not gonna want to hear this since you just drained it halfway.................but I'd dump it again ( the most I absolutely could)..............and start over again. Your cya level is still most likely over 150. Everything is easier to maintain and fix at more normal CYA levels. Plain old bleach will kill your algae and sanitize your water on a regular basis. See shocking your pool and the cya/chlorine charts in pool school. Welcome.

With that high a level of CYA (in excess of 150) you will need to drain as much as possible and refill. If not, you may win this battle, but you will lose the war, so to speak. Unless and until your CYA is under control, you will not have your pool under control. IMHO. :blah:

Good Luck!!!
 
I feared that drain & fill may be needed. I took a sample to the pool place again and they did a dilution 2to1 and found that the CYA is still 200. It looks like I have to empty 75% to bring it to 50. My pool size is approx 13,000 gals. Any idea what are the approx water costs in FL? Would $50 be a good estimate?

At CYA = 200 level is it possible to even get rid of Algae. Here are my readings after 7 hours of putting chlorine. Water looks cloudy (no green)


Hardness 250
Total CL 10 (MAX Read)
FC 10 (MAX Read)
PH 7.8
Alkalnity 120
Stabilizer 150 (MAX Read)

Also, I see some bubbles adhering to the pool surface closer to the top. Any ideas? Is there a leak or ?

Thanks again for all th help & advice
 

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200 CYA is really unbelievable!
Info from the PoolCalculator.com = FC maintenance is min 15 to 23ish.
Regular shock is about 40, and mustard algae shock level is 104! :shock:
Now, as far as I know, we can only test up to 50 FC with the best kit!

If you could replace about 65% of the water, that might get you to about 70. You could live with that.

We are all assumming that the 200 CYA test is correct. You really won't know for sure until the drain/refill dance and then retest.

I fear that you will spend more $ on liquid chlorine/bleach than on the refill water.
You can call your water company and ask about the fee for about 10K gallons of water.
Hopefully they will exclude the sewage portion of the bill for a pool fill.

My Suggestions:
Okay, time to bite that bullet and:
1. Order your test kit
2. Start the drain/refill dance and call the water company
3. Post back here and we will help you take control of your pool!
 
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