Reoccuring Algae

[Hawknz]

Hi All,

Over the last couple of months I have had trouble keeping my pool clear for any great lengths of time. I have performed the SLAM process about 3 times in the past 2 months due to it starting to turn green and I'm baffled.

Every time, I follow the SLAM procedure exactly as it stated, the water clears up nice (after about a week) and it passes the OCLT and looks great, so I let the chlorine drift back down to the recommended level... and its fine for about another 1-2 weeks, then it seems the as the FC gets to just under 7 , it will start turning again, and I have to go through the whole process again.

My test results today are

FC: 7
CC : 0.5
pH: 7.8
TA: 100
CH: 300
CYA: 60

with these results today my pool is again starting to turn slightly cloudy, and its been about a week since I stopped the last SLAM process after meeting all the criteria, the FC has drifted itself back down to this level

Becoming a headache I would rather do without sadly

Any ideas or advise?
Thanks

 

[cowboycasey]

well it looks like your doing very good, I would say your CYA is a little higher than you think.. With a CYA of 70 you need to stay above 5fc at all times... but you want to target 7 if you can..

It sounds like your CYA may be 70 or 80 and your FC keeps dipping below 5/6 fc and you get a bloom..

The only other thing I can think of is greenies still in the skimmer, light, stairs, rocks, etc....

recommend you keep you FC above 7 at all times and target 9 and see what that does

 

[kimkats]

Casey has you covered. I would look all around your pool for hiding places like the light (take it out and clean inside the hole if there is one), returns, skimmer box including the door, etc. Use a toothbrush to make sure you get everywhere. One person found a crack in their skimmer door that was a purrfect breeding ground for algae.

Kim

 

[Jezza]

I agree with Kim and Casey- I think there must be some hidden algae and/or higher CYA than you think. When you are passing the OCLT, that tiny big of leftover algae might be allowing you to pass the OCLT only to multiply again when the FC drops. The hot weather only compounds this unfortunately!

The other thing to rule out is that to ensure that at no time is your FC dropping below the minimum and with the warm weather you have to be extra vigilant with testing to make sure your SWG is keeping up, especially when a Perth heat wave hits

 

[pooldv]

Lots of good advice here. I agree with keeping your FC a little higher to see if that helps. It won't hurt anything and it is safe to swim with FC up to SLAM level for your CYA.

 

[tim5055]

What are you using for testing?

 

[Hawknz]

Hi All,

Thank for your replies.

I have tested the CYA multiple times using the TF-100 and also another local kit with similar results so I don't think its CYA.

I'll have to have a look at the lights, although figuring that out is going to be tricky,

I also have in/outlets for the solar at the deep end of the pool, don't think i'd be able to look around there.

 

[Jezza]

Your light should hopefully be held in by a screw which you can undo by leaning over the edge of the pool and then the light should pop out which if properly installed you can unwind the cable and sit the light on the deck of the pool. Scrubbing behind the light and around the light niche once you have pulled it out could possibly help. (My first SLAM involved large strands of algae behind the light fitting which was holding up completion of the SLAM)!!

Don't forget to turn off the power source to the light when you do this!

 

[tim5055]

Do you run the solar every day or two to refresh the water in the pipes?