Struggling with algae but decent numbers

[az_fam]

We are struggling with yellow algae. This happens EVERY summer and is the bane of my existence. Currently our pool numbers are as follows:

Chlorine - 6.5
pH- 7.6
CYA - 60
VSP runs 9-10 hours a day right now, as we are in PHX and its over 100 degrees.

Our pool is 14062gal gunnite, in ground, VSP, chlorine pool.

What am I doing wrong? Please help!!

 

[jblizzle]

Are you always maintaining the FC above the minimum for your CYA in the FC/CYA Levels? Like always always?

Have you completed the SLAM Process process to ensure everything is eradicated?

Are you sure it is mustard algae? Have you read the article in Pool School about it?

 

[az_fam]

I apologize for the delayed response!

I do not always maintain it above the minimum, just added two gallons of bleach and some tabs to kill stuff. The problem with the CYA, is that it goes up past 60 every year. I feel like we h ave to drain or do a partial drain every 12-16 months. Is that normal?

I am pretty sure its mustard algae, bc I have read the article in the past, but I haven't recently so I could be wrong.

No, I did not do a proper slam.

I did clean the filters this weekend and they were pretty nasty, so I think that may have also had something to do with it.

 

[az_fam]

The algae is yellow in color but maybe it isn't mustard algae bc it does not grow in clumps. It only sticks to the sides and bottom of the pool.

 

[thetekgeek]

Your CYA climbs each year because of the use of tabs. Tabs add CYA to the water and it stays in the water. It is not normal to have to drain every 12-18 months because of high CYA, unless you are adding CYA as part of your chlorination routine. Stick to bleach or get a SWCG and you won't have that issue.

You will need to do a proper SLAM to eradicate the algae that you have. Then follow the FC/CYA chart and you will not get algae again.

 

[Donldson]

You have perfectly answered why this is happening every year. You allow your FC to routinely drop below minimum, you are using tablets which is causing your CYA level to rise, and when you eventually get algae you don't properly SLAM to completion so you never fully remove the problem. It really is that simple, neither the air temperature nor your filtration has anything to do with it.

The solution is really simple: SLAM Process properly and to completion. Attempt no shortcuts, follow the directions exactly, and do not let up until you complete all 3 criteria entirely. Once you finish this do not allow your FC to ever drop below the minimum for your CYA level per the FC/CYA Levels. If you would like your CYA level to stop increasing, you must stop using pucks. Otherwise you must regularly monitor your CYA level and adjust your FC accordingly and drain when it gets too high.

If you do all of this the algae will go away and stay away. I guarantee it.

 

[an1vrsy]

We are struggling with yellow algae. This happens EVERY summer and is the bane of my existence. Currently our pool numbers are as follows:
...
What am I doing wrong? Please help!!

I do not always maintain it above the minimum, ...

No, I did not do a proper slam.
...

You've honestly answered your own question. For a trouble free pool, there are no shortcuts. It's not maintenance free, it is trouble free but it is a process. You can do this. Follow the advice given and you can stop the merry go round.

 

[az_fam]

I read one of the questions wrong, yes I DO maintain the chlorine above the minimum, I read it as above the maximum. I only use tablets 4 months out of the year, in addition to bleach, bu the summers here are 100-120 degrees and I am otherwise out there every single day.

 

[az_fam]

Re: SLAM, it says "Chlorine additions should be frequent, especially at the beginning. Algae and other organic debris will consume chlorine very rapidly at first. As things progress, you will lose less chlorine each cycle and can add chlorine less frequently" and also " You pass an Overnight Chlorine Loss Test (FC loss test shows loss of 1.0ppm or less).

When I added the two gallons of bleach to the pool, the chlorine was up around 10-12 (yeah not SLAM level, I know), the algae was not consuming the chlorine rapidly and I was passing the OCL test, with .5-1 being lost from sunset to sunrise. Just want to throw that out there as well...
https://www.troublefreepool.com/blog/glossary/overnight-chlorine-loss-test-oclt/

 

[mknauss]

If you have visible algae or cloudy water, the OCLT is meaningless. First criteria is crystal clear water. You do not have that if algae is present.

 

[az_fam]

When we get algae our pool is still clear, it builds up on the sides of the pool, not on top of the water and it doesn't get all cloudy. I will attach a photo, I consider this clear, bit there is a bit of algae growing on the wall and on the vacuum.

 

[mknauss]

If there is algae then a complete, properly done SLAM Process will eradicate it. Or you can have sort of clear water with algae and have what you have now.

My pool has never had algae. It has been TFP from the start.

 

[Donldson]

You have algae. SLAM Process is the solution.

Clear water does not have algae in it, your water does.

 

[az_fam]

So you guys think that that water is cloudy?

I will do a proper slam like I mentioned.

Since it is 60ppm for the CYA, should I do a partial drain or just do the SLAM and keep the pool at the 60ppm.

 

[mknauss]

You can do a SLAM at 60 ppm CYA. Shock level is 24 ppm FC. While in SLAM, you can use 5 ml water sample and one drop of reagent to clear is 1 ppm FC. Order more FAS-DPD test reagents now.

Test and dose back to 24 ppm 2-4 times per day. At a minimum in the morning and evening. Should go fairly quick.

 

[az_fam]

Thanks! I better go pick up the bleach at Costco!!

 

[mknauss]

Thanks! I better go pick up the bleach at Costco!!

Don't do that. They only have Clorox. It is 6% and has Cloromax additive, not suitable for pools.
Go to Walmart. Pool Essentials Chlorinating Liquid.

 

[proavia]

As Marty said, not the Chlorox at Costco. Contains additives you don't want in your pool.

Not sure where in Gilbert you are, but you can get 10% liquid chlorine at Walmart in the pool section - Pool Essentials brand. Check the date code... 19xxx - where xxx is the days since January 1. Look for 19150 or higher if you can.

Or go to A&M Corsons for 12.5% liquid. Comes 4 gallons to a crate for $18.23 including tax. These are refillable and initially you pay $6 deposit on the 4 jugs and crate - refunded if/when you ever stop using it. NE corner McQueen & Cooper or NE corner Alma School & Elliot. No date codes as it's refillable, but always fresh.