Green cloudy pool passes OCLT

[swill]

I am a first-time pool owner and I am sure this forum has saved me a ton of money! Thank you to everyone.

FC 7
CYA 70
PH 7.6
TA 80
Passed the OCLT with no loss at all

The pool started to get cloudy just over a week ago with a green tint. Came back from a week out of town to find crystal clear water with a fine green silt all over the bottom of the pool. My dolphin robot made tracks through it like pressure washing a dirty driveway. It also blew a green cloud up through the fan like smoke from a chimney. It has a very fine filter on it that usually catches everything.

I cleaned the sand filter, which had new sand already. The green flowed out of the filter while I moved around the hose for about 20 minutes. I had back washed too. Added 100 lbs of sand for good measure.

Still green. Still cloudy. Not losing chlorine at night. There doesn't appear to be anythimg different as far as tree debris or dust on the furniture that would indicate an addition of dust to the pool. I have read maybe 50 posts on green dust but can't find a solution. The water was crystal clear prior to this with the exception of one algea episode about a month ago when I got cocky and let the FC get too low. A SLAM fixed it right up.

Is it possible that I have accumulated dust that is to small for the filter or the robot? Should I SLAM it just in case? Thanks for your help.

 

[cj3737]

What is your CC?

 

[duraleigh]

SLAM the pool. The OCLT is not bulletproof and will often show 0 loss if you are not brushing your pool regularly (Everyday during the SLAM)

 

[swill]

Started slamming. I had been brushing with the robot regularly so the silt on the bottom was all in suspension. This led me to believe that the silt wasn't organic since none of the chlorine was burning off at night. But perhaps the the CYA was holding on to the chlorine that was there and there was no more chlorine to give. That would explain why the algae came back. Or maybe my CYA is higher than I think it is. I'm using the TF-100. I'll drop a sample at Leslie's today to double check my numbers. Thank you for the advice.

 

[pabeader]

No need to go to the Pool $tore. They are less consistent then you will ever be.

 

[Donldson]

I'll drop a sample at Leslie's today to double check my numbers. Thank you for the advice. [/COLOR]

If the test results Leslie's gave you were trustworthy then you wouldn't have had to buy the TF-100. Why would you go someplace known for questionable test results to verify the kit you invested in for accurate results?

 

[BuckeyeChris]

Did you have your pump running all night with the SWG set to 0%? If the SWG was on over night you can't get an accurate OCLT result.

 

[max2k]

...Passed the OCLT with no loss at all...

was SWG running at the time? If it was it doesn't count and you'd need SLAM for sure: if your pool was algae free you'd observe increase in FC overnight from SWG.

 

[swill]

I had turned off the SWG for the OCLT.
The pump has been running on high full time for several days.
You are correct about the pool store. I should trust myself more.
I started the SLAM about 24 hours ago and have kept the FC above 30ppm. It is a much lighter green now. Definitely algae. Will continue until clear and blue. I clearly should have started the SLAM the moment I noticed a tint of green. We live on an inland bay in Virginia Beach. There may have been some bay swimming followed by pool swimming without rinsing off. The local wisdom says that doing this may cause an algae bloom in your pool! I plan to keep my FC level at 8-10 with a CYA of 70-80. This should be okay, right?

 

[max2k]

I had turned off the SWG for the OCLT.
The pump has been running on high full time for several days.
You are correct about the pool store. I should trust myself more.
I started the SLAM about 24 hours ago and have kept the FC above 30ppm. It is a much lighter green now. Definitely algae. Will continue until clear and blue. I clearly should have started the SLAM the moment I noticed a tint of green. We live on an inland bay in Virginia Beach. There may have been some bay swimming followed by pool swimming without rinsing off. The local wisdom says that doing this may cause an algae bloom in your pool! I plan to keep my FC level at 8-10 with a CYA of 70-80. This should be okay, right?

if you read your CYA level correctly, water stabilized with no algae in sight (FC overnight loss < 1 ppm) then you can even go lower on FC when you get SWG back on.
Rinsing between swims shouldn't be required unless you go back and forth entire day. Even in that case your FC would go down and if you monitor it properly you'd notice, bump it up with bleach- problem solved.

Blooms happen when you let it go on its own for few days, FC drops below minimum for one reason or another and stays there for couple days unnoticed.

you should use Non-SWG part of the chart for SLAM, line 80 FC=31. I don't think SWG makes any difference during SLAM but it surely causes confusion. SWG is unable to produce FC levels on its own, its only purpose is to compensate FC daily loss when things are running normally.

Don't go to the store for 'calibration'. If anything you should be offering them such a service to calibrate whatever thing they're using for testing as your kit is most likely more precise .

 

[Kiss4aFrog]

Always trust yourself over the pool store but I'm in the minority where I will say if you're confused about your readings I'd try for the second opinion at the pool store. If there is a big difference I'd surely trust my own testing over theirs but retest to see if I come up with the same number.

Did you take a sample to the store and if so did they give you a reading on metals, copper ??

 

[swill]

I haven't taken a sample to the pool store, yet.

48 hours after adding the first six gallons of bleach, the green is gone. 12 gallons total. It was still a light green this morning but it suddenly became blue around noon. Now it's just a bit cloudy. I'll try an OCLT tonight.

I am grateful to everyone for your advice!

 

[Her pool boy]

The mistake I made when I did my first slam is I stopped too soon. Be patient. You can swim up to your slam level so make sure you pass the three criteria of a SLAM before you stop CC is .5 or less, you pass the OCLT, and the water is clear. Good Luck.