Having reocurring alge growth all summer

[dirtdogks]

This is the worst year in 30 years of pool ownership for us. I cannot even count how many times that my pool has been slammed this summer, blue and then turns green again. I always use the chart showing the FC level for my acid level and slam the pool accordingly. I usually add a little extra and maintain that level overnight. About a week or so later I am starting to get green again even though I have chlorine in the pool. I use the pool store a lot for test but also have the Taylor 2006 test kit (new this year). I maintain my water perfectly except my PH creeps up at times because I use a lot of liquid chlorine which raises my PH. Right now I am also using the 53% cal-hypo because I am tired of dealing with the huge volume of chlorine this season. We are getting ready to go on vacation for 1 week and am trying to get it in line before and then drop in some tabs while we are gone. My acid is currently at 43 ppm. I have my PH back down to 7.7. Right now my FC is around 20 ppm (which is high). I know that the weather has been weird this year but this is crazy!

 

[MarianParoo]

I don't have much time tonight to answer you completely, but it seems like you are misinterpreting the SLAM directions. A SLAM is not just getting to "shock level", but maintaining that level until you meet the 3 criteria for passing the SLAM. See: Pool School - SLAM - Shock Level And Maintain

You say your acid is at 43ppm.... Was that a typo? Or do you mean CYA? If CYA, assume it is 50 and plan accordingly.

 

[JamesW]

If you're getting algae, it's because the FC is not being kept high enough.

 

[cowboycasey]

are you sure you have CYA at 40, you said 43 and that is a pool store number....

Use your K-2006 and test it, outside in the sun with the sun to your back and make sure what your CYA is at..

The SLAM is is not a 1 or 2 day event, you will need to complete all 3 things to finish a SLAM..

If you are at 40 CYA then 20 for FC is good, you will need to keep it above 16 at all times until the SLAM is finished...

the OCLT will tell you when you have no algae left in the pool

please do all the tests in the K-2006 and post up your numbers so we can help out

FC
pH
TA
CH
CYA

 

[dirtdogks]

Yes, CYA

- - - Updated - - -

Will do

 

[JVTrain]

SLAM - Shock Level and MAINTAIN. The maintain is the critical part. Shock levels of FC have to be maintained until the 3 criteria in the SLAM procedure have been passed. After those are passed, adequate levels of FC must be maintained based on accurate CYA level testing. This can only be reliably done with your K-2006 kit yourself. Pool store testing for CYA is nearly always terrible for this very important test.

 

[dirtdogks]

First thing this morning tests: Pool is more blue then green and clearing.

FC 26.5
pH 7.7
TA 110
CH 430
CYA 43

 

[dirtdogks]

I'm not sure why the pics appear green from the camera. They are blue. The spots in the one pic are concrete. The bottom needs to be painted.

 

[cowboycasey]

ok, your using the pool store CYA number again, please do the CYA test with your K-2006... the pool store test is suspect at best and most likely wrong...

At your FC level or anything above 10 FC will give a wrong or off PH level, so wait until you are below 10 to test PH again...

 

[dirtdogks]

No, I'm not. I ran ALL of these tests this morning with my Taylor K2006 kit. Let me go get the kit. I added the cloudy solution until the black dot disappeared. It was a little above 40 and I guessed 43.

 

[chem geek]

If it's between two values, you round up and use the larger value. The scale is logarithmic, no linear, and it's safer to use the rounded-up higher value. So if in between 40 and 50, use 50 ppm as your CYA value.

 

[dirtdogks]

Yep, the solution was between 40 and 50 and I thought it to be about 43. Am I doing something wrong? When I ask for help I try to listen to the person that is helping me

- - - Updated - - -

Sorry, I see the note above now so then let's call my CYA 50 then.

 

[Defgufman]

When performing a SLAM, all 3 criteria must be passed for it to be complete. Perhaps you are raising it until it looks clear and stopping....that won't work. Any algae that is hiding in the ladders, inside the lights, or in the skimmer will make a comeback once you quit the SLAM too soon.

 

[dirtdogks]

That must be it. Maybe I have been just lucky the last 3 decades also . I did open it really late (early July). It was clear but the bottom was dirty and I did not vacuum to waste. I was having a real hard time for a while getting chlorine to stay up. What I am doing now is running the robot every day and the taking the brush to the ledges and ladder (steps and under). I will try to be more thorough this time. I am leaving tomorrow for a week. Any suggestions for me to do before then?

 

[cowboycasey]

Yep, the solution was between 40 and 50 and I thought it to be about 43. Am I doing something wrong? When I ask for help I try to listen to the person that is helping me

- - - Updated - - -

Sorry, I see the note above now so then let's call my CYA 50 then.

ahh, sorry that makes sense.... there is no number between 40 and 50 so usually when we see numbers like 43 I think pool store... and you are not doing it wrong

Ok, so you will need to continue your SLAM until all 3 are met...

Your FC is perfect above 20fc for your CYA level, just keep it above 20 until your done...

you can raise the FC to mustard level of 30fc but it probably wont stay up for the week... any way you can have someone stop by and pour a gallon in once or twice while your gone?