Algae and FC question?

[EJ39]

About 4 weeks ago I noticed a small amount of algae in various spots in my pool, I followed the SLAM process for a couple days and passed all 3 criteria with no problems.
So I bumped my CYA up to 70-80 and have been keeping my FC between 7-8. So my first question is there any issues running FC at 7-8 all the times?

At this point my pool is crystal clear and zero signs of algae for the first 2 weeks or so after the SLAM, honestly it’s never looked this clear but now after 5-6 days I am finding a small amount of algae in the corners of my steps and the corner of my swim out, I brush it and it’s gone for 5-6 days. Do I need to slam? I’m assuming these areas are getting less circulation. I’m still passing the OCLT without a problem and the other areas that were showing algae have not reappeared.

 

[PoolGate]

If you follow the instructions for cya and fill the tube until the dot disappears, your cya level will be lower than you think. The instructions for cya, imo, are wrong. Just fill until you see a faint outline of the dot. I verified this with the 50ppm reference solution. Try this I'd be curious what your level shows.

Keeping 10% cya is fine that's what I do.

As to algae, the answer is always, "not enough chlorine". Run a slam again.

 

[Bperry]

About 4 weeks ago I noticed a small amount of algae in various spots in my pool, I followed the SLAM process for a couple days and passed all 3 criteria with no problems.
So I bumped my CYA up to 70-80 and have been keeping my FC between 7-8. So my first question is there any issues running FC at 7-8 all the times?

At this point my pool is crystal clear and zero signs of algae for the first 2 weeks or so after the SLAM, honestly it’s never looked this clear but now after 5-6 days I am finding a small amount of algae in the corners of my steps and the corner of my swim out, I brush it and it’s gone for 5-6 days. Do I need to slam? I’m assuming these areas are getting less circulation. I’m still passing the OCLT without a problem and the other areas that were showing algae have not reappeared.

if your CYA is 80, the FC range is 4-11ppm. IMO, don’t let it get down to 4. If algae has come back that soon after a SLAM, it’s likely you weren’t done with it rather than circulation. Can you post some test results history?

 

[Orion7319]

About 4 weeks ago I noticed a small amount of algae in various spots in my pool, I followed the SLAM process for a couple days and passed all 3 criteria with no problems.
So I bumped my CYA up to 70-80 and have been keeping my FC between 7-8. So my first question is there any issues running FC at 7-8 all the times?

At this point my pool is crystal clear and zero signs of algae for the first 2 weeks or so after the SLAM, honestly it’s never looked this clear but now after 5-6 days I am finding a small amount of algae in the corners of my steps and the corner of my swim out, I brush it and it’s gone for 5-6 days. Do I need to slam? I’m assuming these areas are getting less circulation. I’m still passing the OCLT without a problem and the other areas that were showing algae have not reappeared.

Your running a SWG. I had the same thing happen to me last year, and couldn’t figure it out. Basically you have to keep in mind that a SWG is going to add just a tiny bit of chlorine all the time and that means that it’s going to be more suspect to dramatic dips that you won’t notice because it will build back up eventually. That’s one of the reasons with the higher CYA in a salt pool. What helped me was when @Newdude advised me to run mine 24/7 and target my FC just a bit hot. If you have a variable speed pump there is no reason not to do so. This will keep a constant reserve and your a lot less likely to get an unnoticed dip in levels. Also it helps to brush more or run your robot more.

 

[jark87]

So my first question is there any issues running FC at 7-8 all the times?

That’s where I keep FC. My CYA is a little more subjective. I “think” it’s at 70, but who knows. I hate that dot test. I’m going to order the 50ppm reference to see if I can achieve more accurate results.

 

[EJ39]

I don’t have the history for my slam, I wrote it down on paper as I did it but did not keep it.
Since the end of the SLAM I have tested multiple times a day trying to dial in the SWG the lowest I’ve seen the FC was 5.5. I would say 90% of the time it was in the 7-8 range. I agree with the CYA test being difficult to get a solid number.
I just ordered the 50ppm standard to help with my testing.

 

[Mdragger88]

Have u tried pulling samples from those areas to test fc? The may have less fc due to poor circulation.
I always pull my sample near my steps because of this - that way I know I have more than enough fc even in the lower circulation areas.
Do your best to adjust the returns to accommodate this. You can throw ping pong balls or something similar in & watch what happens/where they end up, get stuck etc.
Readjust jets & repeat until u are happy with the outcome .
At any rate- If u see visible Algae you need to SLAM Process.
It’s possible u stopped the last one a little too soon.
Holding slam level for an extra day after passing all 3 end of slam criteria is good insurance.
Be sure to check/scrub any possible algae hiding places (light niches, ladder handrails/rungs, drain covers, skimmer throats, weir doors & the foam) - don’t just assume the high chlorine levels will do the trick.

 

[EJ39]

I have not tried testing those areas but I certainly will, I checked all those areas except for behind the lights and they were clean. I was hesitant pulling the light myself, I have 2 Hayward color logic lights. Anyone have experience pulling one out?
I’ll try to draw a sketch of the pool later but I have 3 returns, they are all currently pointing straight into the pool.

 

[Mdragger88]

You want the jets to do a couple things -
circulate chlorinated water all over the pool minimizing dead spots if possible
&
Effectively direct debris towards the skimmer (prevailing winds play a role here too as do properly functioning weir doors & appropriate water level)
Here’s the instructions on those lights -

https://hayward-pool-assets.com/assets/documents/pools/pdf/manuals/colorlogic-installation-operation.pdf

If u know the exact model u have hopefully there’s a YouTube video for removing it.
Posting a pic of it will help too.

 

[EJ39]

Here is a rough drawing, any suggestions on how to point the returns? Is it better to have them slightly pointed down to help mix with water

 

[mknauss]

What direction is your prevailing wind at the pool surface?

You want the returns to gently create a 'toilet bowl' effect, working with the wind, to direct the floating material to a skimmer.

 

[Mdragger88]

Start Pointed Down a little & all of them pointing to the left so the water flows counter clockwise towards the skimmers .
With the one in the corner at the notch pointed towards the other corner so some of the flow hits that area & some goes past the other corner
See if the wind works against u that way if so go clockwise

 

[EJ39]

What direction is your prevailing wind at the pool surface?

You want the returns to gently create a 'toilet bowl' effect, working with the wind, to direct the floating material to a skimmer.

More or less from the deep end blowing towards the shallow end.

 

[mknauss]

Follow what mdragger stated --

 

[EJ39]

So back to the algae, I realize I have to SLAM again. How do I know I’m done considering I’m currently passing the Oclt with no problem and it takes around 5 days for the algae to come back. Should I just maintain shock levels for those 5 days?

 

[PoolGate]

Can you share your test results on your username through the app? Are your reagents new? I am not really buying that circulation is your problem.

 

[EJ39]

Yes I can do that later today. My Taylor test kit is new this season.

 

[EJ39]

I’ll had them to my log but my numbers are,
FC 11.5
Cc 0
Cya 70-80
Ph 7.6
Ch 70
TA 70
The FC is high from my adding a galling of chlorine last night, I only had a gallon left until I go today.
ph was measured last night when chlorine was below 10ppm.

 

[EJ39]

So I may have found my problem, should have not been lazy last time. Just pulled the trim ring off the lights and can see visible algae, not a ton. If I take those out and clean them by hand do you think a full slam is necessary?

 

[Mdragger88]

So I may have found my problem, should have not been lazy last time. Just pulled the trim ring off the lights and can see visible algae, not a ton. If I take those out and clean them by hand do you think a full slam is necessary?

I would raise to slam fc until u pass ALL 3 end of slam criteria. Hopefully you’ve found the culprit & it will go quickly.