Cloudy and confused

[Barbara C]

I've been using the BBB method for two years and have been very happy. I feel as if I understand the process, perhaps I don't! Our pool is a green mess right now. I added 13 oz.CYA over the weekend to start bringing that level up from what I thought was around 19 (pool store reading using LaMotte fancy tester.) I was surprised at that low of a reading when I had tested and came up with close to 30 but had only about 2/3 the amount of reagent needed. I have refills on order even as we speak! After adding the CYA everything went downhill very quickly. I had been keeping the chlorine at 3-4 since the CYA was low enough. Even after adding 13 oz. that would have brought it up to about 26. That's the backstory
Even though I have started to shock the pool to bring the algae into submission, my FC isn't dropping, any. The sun was off the pool when I started and now it's dark.
I backwashed the filter before I started but wasn't able to rinse because the water level was getting low. Now 2 1/2 hours in, it is still in good shape.
This all brings up a few questions. Why did I develop algae to begin with?? Why isn't the FC dropping and I didn't even show any CC on the last test.
FC 15
CC 0
pH should be 7.2 (lowered before I started shocking)
CYA 26?
TA 100

Any ideas?

 

[jblizzle]

What did you test the CYA to be?

As you must know we do not trust pool store tests.

Oh I see you are waiting for more reagent. I am guessing that 3-4 ppm was too low for your actual CYA. Was that the lowest you let it drop?

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

 

[Richard320]

Algae happens if things are just left alone. You might as well ask how come you have weeds in the flower bed, you cleaned them all out last fall!

Your bleach may be stronger than the label says, so it went higher than you calculated, and now it's down. That's one possibility. Your CYA may be much higher than you think, which will require higher levels than you think to get "active". Or things may just need a little more time and a little more brushing.

 

[Barbara C]

Those are the answers I thought I'd get. I'm a numbers sort of person and didn't let it go below 2.5 on the FC, testing daily. I can't wait to get my reagent refills to test the CYA to see what it really is. Should be very interesting, 26 or 36!
Thanks. I think I'll go scrub the pool now.

 

[Barbara C]

So this morning at 11:15 my FC hasn't gone down by hardly any. I didn't get up to check it before the sun hit it but the reading was still at 16. The water is looking a little clearer but I don't want to put more bleach in, it's high enough!
Is it possible we have a filtration problem? The sand was changed out in 2010 when we changed from Baquacil. We don't have a heavy bather load or any of that. We needed to replace the spider gasket this year because of leaking from the backwash tube. No other maintenance other than backwashing has been done. We do use a skimmer basket sock.
Any other ideas would be greatly appreciated.

 

[Barbara C]

The algae ordeal is over. The cover is clean, floor vacuumed and we're just waiting for the FC to come on down. I guess there's wasn't a filtration problem after all! I just needed to be patient. This was our first bout with algae so I wasn't sure what to expect. I will say, at the beginning, I was dubious about the CYA reading the local pool store gave me. Now that I've been able to check it myself (thanks to TFTestkits for getting my order out so quickly!!) I have found that the pool store was right on the mark. I guess they're not evil incarnate after all!
It should be a good weekend for swimming. The high is supposed to be 92 tomorrow!

 

[Suziqzer]