Can't keep chlorine levels up

[Cbusto]

Hello, new member here. This is my third with a new build pool and I can't keep chlorine levels to stay in the proper range this year after the weather warmed up here in Arizona, or for the past few weeks even read FC at all. I have read and researched possible causes online which lead me to join the TFP community.

The pool has had what I thought was small amount of dust/dirt not being filtered out. Well as of this past weekend I noticed a few small yellow patches in two of the corners of the tanning ledge. I'm pretty good at keeping my numbers in check but now the SWG will not even show a FC reading more than 1ppm. I run the pump for 10 hours at 100%. I cleaned the salt cell and filters a second time this year. I would shock the pool only for the chlorine ppm to fall rapidly in a day or so.

After reading many posts and threads here I think I'm at the beginning stages of mustard algae and it is eating my chlorine faster than I can produce. So I have started to SLAM my pool. Before I raised my chlorine to SLAM level these were my readings all done with Taylor test kit:
FC 0
CC.5
PH 7.5
TA 80
CYA 60
CH 460
According to math school my SLAM level would be FC 24.
I'm on my fourth day of the process and the water is very clear with CC 0. The overnight test still shows a FC drop from 24 to 19. Am I correct to continue with the process until I get a overnight loss of 1ppm? Then raise the FC to mustard shock of 34 for a night?

 

[Bperry]

Yes that’s the process. But it’s probably just regular algae. Yellow doesn’t mean mustard necessarily. 4 days isn’t very long yet. Keep dosing back up to 24 as often as you can through the day.

 

[Cbusto]

Question. On day six of SLAM and have seen dramatic improvement on what I considered "clear" water. Should I be checking or concerned with the Ph level thru the process? I've been brushing 2 times a day and adjusting chorine up to SLAM level of 24 4-6 times a day. Still using a lot of chlorine in the OCLT. Goes down to 19 from 24 each night.
CYA 60
TA 80 at start of SLAM
PH 7.5 at start of SLAM

 

[mknauss]

Should I be checking or concerned with the Ph level thru the process?

No. Deal with it when your FC falls below 10 ppm.

 

[Cbusto]

Thanks, I'll hold course for the SLAM.

 

[Cbusto]

SLAM day 8. Kids are getting anxious to swim. Is it safe for them to swim at or slightly below my SLAM FC level of 24? Pool has been clear for days now and brushing results in a few very small poof of dead algae. Last two nights OCLT have been been sunset FC 25 and sunrise FC 22.5. CC has been 0 for 3days now.

 

[mknauss]

They can swim. May get some eye or skin irritation if pH is out of range.

 

[PoolStored]

Last two nights OCLT have been been sunset FC 25 and sunrise FC 22.5. CC has been 0 for 3days now.

Did you remove and scrub any ladders (including inside the tubes). Did you remove and scrub behind any lights? Did you scrub the skimmer and check the weir doors for algae? Did you remove main drain cover and scrub the main drains?

 

[Cbusto]

No ladders, pulled out metal stools, cleaned and left out. Small led lights, just brush around each time I brush . Cleaned all inside of skimmers and auto fill. Don't know how to remove paramount floor drain. Been running water feature and hot tub jets once daily in the evenings also. Am I correct that the OCLT should be less than 1ppm from the SLAM level of 24? Or should I let it drop a bit to perform the OLCT? The kids will be happy they can a least jump in! Temps are going up close to 110 this weekend.

 

[mknauss]

If you are passing the other two criteria, then let the FC drop to mid teens and do the OCLT at that level. Be sure your test vial is clean.

 

[PoolStored]

Don't know how to remove paramount floor drain. Been running water feature and hot tub jets once daily in the evenings also. Am I correct that the OCLT should be less than 1ppm from the SLAM level of 24? Or should I let it drop a bit to perform the OLCT? The kids will be happy they can a least jump in! Temps are going up close to 110 this weekend.

Had at least three pools this spring that sat like yours until they cleaned the main drain. Do you know the model number? Can you take a picture?

Safe to swim if you can see the bottom and FC is between minimum and SLAM. Have at it.

 

[Cbusto]

Main drain is MDX-R3.

 

[PoolStored]

Hard to tell from that pic, looks like the MDX-R3 drain. Dive down and look, you should see three screws...noted as "2" that hold on the cover (1) to the funnel assembly (3).

That may be enough to scrub.

You may need to remove 4 additional screws that hold (3) to (5), remove 3 and scrub and scrub inside (5).

Use a bottle brush or the like to scrub all the parts...

https://www.1paramount.com/wp-content/uploads/2017/03/MDXR3AdjustableConcrete.pdf

 

[Cbusto]

Looks like I'll jump in tomorrow and clean the drain. Thanks for the info, this site is a great place! I'll let you know what I find.

 

[PoolStored]

Looks like I'll jump in tomorrow and clean the drain. Thanks for the info, this site is a great place! I'll let you know what I find.

Might need a dumbell to hold you down. Do not attach weights to your person, only something you can hold on to...

 

[willygee]

No. Deal with it when your FC falls below 10 ppm.

This is because ph testing is inaccurate when FC above 10ppm correct?

 

[mknauss]

This is because ph testing is inaccurate when FC above 10ppm correct?

correct

 

[Cbusto]

Ok, I went in yesterday and looked at removing the drain cover. It has screws that require a special tool from paramount to remove. Ugh. Anyway, I was able to scrub under the cap and am pretty confident there is or was no algae. So now I'm at the point in my SLAM that I have met all three criteria. No visible algae, pool is very clear, and my last two nights for OCLT have been: two nights ago from FC 23 to 22, CC 0 and last night FC 22 to 21.5, CC 0.

Am I safe to stop the SLAM and let the FC drift down and balance the water or should I do a MA SLAM tonight?

 

[PoolStored]

That's a pass. I don't think you NEED MA SLAM, but if it makes you feel better, better to do it now!

 

[Cbusto]

How far should I let the FC fall to before I turn my SWG back on? The math app shows my target range for FC 3-9. Am I correct to turn it back on at the high end of that range and try to maintain FC at the upper end of the range?