Having to SLAM every 4-6 weeks?

[MarcBalcer]

Howdy,

Wanted to see whether this is to be expected or not. Over the last year and a half, algae has appeared in the darker corners of the pool and on the steps about 4-6 weeks after a SLAMming. Under normal conditions, our FAC using the SWG is between 4 and 6 every time I test, morning, noon or night. I don't think I've ever measured below 4. After SLAMming, which goes pretty quickly (doesn't take long to have <1ppm loss overnight), it is crystal clear under we notice algae again a month later. I brush the pool carefully 1-2x / week and run the robot cleaner every couple of days.

Any suggestions to avoid regular SLAMing or is that the norm?

I did testing with my own kit and brought it to the pool store too - CH disparity is interesting. I find the CyA test hard to eyeball but the dot is definitely gone at 30 and still there at 40.

All Taylor Tests (pool store test)
FAC 5 (4.4)
TAC 5.5 (4.7)
pH 7.8 (7.5)
Alk 110 (99)
CyA 35 (52)
CH 650 (254)
Salt (pool store at 3100)
Phosphates (I know, pool store at 1000)

 

[JamesW]

Algae means that you are not maintaining the chlorine at adequate levels.

It really is as simple as that.

Keep the FC at higher and more consistent levels.

 

[JJ_Tex]

+1 on the above. Your pool is telling you it needs more chlorine. A SLAM should not be a normal routine and proper FC levels will ensure you never have to SLAM again.

As you can see from my avatar, I keep my FC much higher than 5 in my salt pool and never have had a speck of algae in it.

 

[Jimrahbe]

Marc,

You should not have to SLAM more than once.. If you have to do it more than once, then you are just not doing it correctly.

You are not killing all the algae before you quit the SLAM, or your CYA is higher than you think, and are SLAMing at a lower level then required, or you are not brushing and making sure all the hiding places are clean.

Also, once you actually complete the SLAM... do not try to keep your FC between your target and your minimum. You want your FC to stay in your Target Range or higher at all times, not just for the five minutes after you test.

Thanks,

Jim R.

 

[MarcBalcer]

Thanks all. SLAM in progress. I pulled out the pool light and scrubbed like heck. I always do the skimmer, hinge door, etc. Only last thing that is possible is under the two drain covers. Do I have to get in there too? Really hope not to have to go diving but I have done it before

The message I am getting is to run at a higher chlorine. 7 I guess? (Or more per J As I said, the chlorine level stays pretty stable with the SWG in the 50pct range i hrs a day and I dont recall a reading under 4.5 under everyday/normal operating conditions. I guess that wasn't enough . . . Sound good?

 

[Newdude]

I dont recall a reading under 4.5 under everyday/normal operating conditions. I guess that wasn't enough

How often do you test ? A couple days is enough for an high loss event to happen, or the cell to shut off for 12 hours, and put the FC back before you notice.

I caught my cell off 7 or 8 times last year during/after big storms. If the cell runs its self check before it's well mixed, it'll shut off with low salt for 12 or 24 hours. On any given day its not likely but over a season it may happen several times.

 

[MarcBalcer]

Yeah, could be. I do either a FAS/DPD or the chlorine/ph guess the color test every other day or so. Gonna get on a more regular daily schedule after the SLAM is done to see whats up.

 

[Newdude]

Gonna get on a more regular daily schedule after the SLAM is done to see whats up.

What was the schedule ? Nobody will point a finger, I promise. SWGs are so boring they lull us all into complacency.

Well. Until they get bit at least.