Algae keeps coming back

[mknauss]

You do not show a robot in your signature. What do you have? It should pick it up when you run it.

 

[jandersen13]

I have a Dolphin M400. I’ve run it everyday the last few days, if not once, twice. But it still seems there is always the dead algae in the same place on the floor and steps by a return line. Is the filter not filtering it out?

The water is blue and clear. But just a few spots of the dead algae. And then in the deep end when I brush an angled wall it kicks up the “dust”. So do I still have active algae?

 

[mknauss]

You are still clearing out some of the more resistant algae. If you have a light niche be sure to check that. Also any steps, weir door, skimmer, etc.

 

[jandersen13]

And just tested my TA and PH. Both are a bit low now so I’ll adjust those back up. Would that have any affect?

 

[mknauss]

What is your FC? pH testing with FC above 10 ppm is not valid.

pH can be raised by aeration. What are the pH and TA test results?

 

[jandersen13]

FC - 11ppm
CC - 0ppm
TA - 70ppm
PH - looks about 6.8 or 7

 

[mknauss]

I would not do anything with pH or TA.

Stay at your SLAM. No need to test anything but FC during it.

 

[jandersen13]

Ok thanks! Looks like I’m having a bit of trouble staying at shock level, close but not all the way there. That also means there is still some algae, right?

 

[mknauss]

Most likely. You are getting FC loss during the day to the sun.

 

[jandersen13]

Any suggestions for how to help with that?

 

[mknauss]

Not really. Winter helps it, but that is no good for pool use!

With the elevated FC for your SLAM, your loss from UV is higher. Get the SLAM done. Then use target range FC.

 

[jandersen13]

My only problem is I feel as though I’m close to done with the slam but can’t get over the finish.

 

[Katodude]

So a couple of things I just noticed. I think you said your new CYA level is 50, if that is the case then your SLAM level is 20 for FC. If you keep you FC lower than that the SLAM will take longer. The more often you adjust your FC to 20 the less time the SLAM will take.

Also when running your M400 make sure you are using the fine pleated filters. That will help you clean our the deal algae.

 

[Casey]

Also, your water may appear clear to you but it is not. When your water looks like this, you can do an OCLT. You want to see it shimmer like a Diamond when the sun hits the water.

 

[jandersen13]

Things are progressing and looking good now. I think it’s just a matter of filtering to clear the last bit up.

We are getting hit with some heavy rain right now. What’s my best approach after this to not screw it up?

Alkalinity and PH tests won’t be accurate right? Any suggestions on how to test / proceed today?

 

[IceShadow]

If you can test in the rain (no lightning) then you can keep testing and adding. Rain won't really affect much. Even if it gets high enough you have to drain some off it's going to be pretty minimal compared to the total pool volume.