Worrying signs - algae there?

[simonoaks]

Having successfully completed 2 SLAMS in the last 3 months, the last one finishing about 4 weeks ago, I am getting warning signs I got before - i.e. SWG losing too much, very slightly over time.

Two weeks ago, we were having the house painted on the outside, and as part of that, they power washed the whole pool screen. There was all sorts of debris in the pool after - leaves, dust (when I brushed it , I got brown clouds) , flakes of old paint etc. I did chuck in some bleach and raise the FC to 24 before they started. Of course, there could well be a whole bunch of stuff that washed in the pool that is not even visible to to the eye.

Anyway, I left pump running but SWG off, after they had finished , to let to FC naturally drop, over 5 days. Once it got to 10 , I put on SWG on 20%. Pump run time the same - 10am to 6pm.

These are results:

8/5
12.30 pm
fc 10 - swg 20%

changed to 30%
---------------------
8/10
10 am
fc 9
swg 40%

---------
8/11
10am
fc 9
------------
8/12 and 8/13
10am

fc 7.5

SWG 50%
--------------------
8/13
6pm
fc 6.5

swg 60%
-------------------
8/15
10.30 am
FC 5

I know I need to do an overnight AGAIN, but other than this worrying drop with increasing SWG %, anyone think of anything else it could be. I am pretty sure, I am going to have to do yet another SLAM - as the signs are the same as before. Just turned up SWG to 80%, will test again today at 6 pm. It should go UP not down , if everything is ok.

thx

 

[Richard320]

You might have a bunch of stuff hidden inside the filter from the pressure wash. Just because it isn't in the pool anymore doesn't mean it's not in the same water. The FC will try to oxidize it. Try cleaning the filter before you do the OCLT.

 

[simonoaks]

Yes, I brush pool 2-3 times per week, and clean cell, filter, skimmer and pump 1-2 times a week - 3 times per week since the cleaning was done.

Tested at 6pm and got FC 8.5, which is good - up 3.5 on the day , although pretty cloudy today, could be a good sign. Last time I had to SLAM , I was losing 3ppm per day at 100%.

Will drop it down to 60% and see what happens tomorrow. If that does not work, I guess I will have to do the whole OCLT thing again.

 

[YippeeSkippy]

You don't mention what your CYA level is?

 

[simonoaks]

CYA is 60-70

8/16
11.30 am
FC 7

So, it has lost 1.5 from pump off at 6pm last night to pump on at 10am this morning. So borderline - about 4-5 hours of sunlight with no pump on.

 

[simonoaks]

8/16
8 pm
FC 7
SWG 60%

So, it could actually be about perfect right now, IF I do not have any algae - holding at 7ppm all day. Will know in the morning.

 

[simonoaks]

8/18/15
9.45 am
FC 5

Was busy yesterday at Kennedy Space center, so no testing.

FC 5 this morning, so still boarder line , as pump not on yet, so it had 6 pm to sunset last night, plus sunrise to now with no FC generation, so COULD be ok.

Did get slight pink on CC test for first time in months - less than .5 though. Would exactly does that mean?

thx

 

[Texas Splash]

CC is that "trash" chlorine still in transition. A little pink on the CC test simply means you have some organics that are being eliminated by FC and have not yet been fully oxidized. A little (<.5) is acceptable.

 

[simonoaks]

I passed the overnight 2 days ago , and holding at fc 6 at 10.30 am and 7.5 by time pump goes off at 6pm. So happy with that. CYA is 60-75 ( who can really tell ) , I think it is impossible to really get exactly between 70-80 until a way better test method comes out. Now...... after 4 months of taking control of my pool, should I go down the Borate route? I guess that is a whole new area of research to do ?

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