odds and ends of small issues

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Hi Pool peeps. I can't find one thread that covers it all to ask the questions so here I go.

How does one deal with mustard algae attempting to grow behind a submerged pool light beyond brushing it out every 5 days? I don't use algacide now. I maintain FC of 7-10 (which seems to keep the below algae issues from going nuts, when I go lower I struggle more), TA at or about 100-120 (see below for more info on this), CYA is presently at 80, pH is 7.4-7.5.

In the creases of my ladder I also get what appears to be some sort of mustard algae attempting to grow. Yes I brush weekly using a mask and snorkle to get close and inspect my entire pool.

I have fill water that is high in alkalinity. What is the pros and cons of constantly fighting the chase of the number 80 because I can't get to 100, let alone 80. By the time I get to 100, I need to top off my pool again. And no, I have no other water source available from which to fill my pool. The higher alkalinity...is this why my salt cell gets that blue-white build up??

Lastly, if my FC is usually around 7-10, should I bump my CYA to 90??

Side note, I had considered borates but have given up on the idea due to a lower TA being unattainable. Any suggestions on the above issues would be greatly appreciated. My water is crystal clear and I've not let anything cloud it up. I'm a bit anal retentive about keeping it very clean given the past algae issues and on going struggles with the light and ladder. :(
 
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ajw22

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Jul 21, 2013
19,794
Northern NJ
You don't say what your fill water TA is but don't worry about it. Do the best you can to lower it.

Don't bump your CYA up above 80. I would rather see your CYA at 70.

Have you done a Overnight Chlorine Loss Test? When was the last time you did the SLAM Process? What makes you think the algae is mustard algae? Have you done...

 

IceShadow

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Jun 8, 2019
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Milwaukee, WI
Don’t worry about TA. It will fall when you add acid. You just need to know what it is when you add acid to properly judge how much to add.

Lower output or runtime to let FC come down instead of raising CYA.

See the article on Mustard Algae in Pool School above to deal with that.
 

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
ICE and AJW:

Ok, first my tap water TA is 280. I did decrease my SWG last night to 20% and my FC went from 9 two days ago to 5 today. Let me do it this way

6/18:
FC 9
pH 7.2 (trying to get TA down)
TA 120
CYA 80

Been aerating the last two days.

6/20:
FC 5
pH 7.2
TA 120
CYA 80

I need to fill my pool again from evaporation and aeration. And I still don't have my TA any lower or my pH up any higher. I've adjusted my SWG back to 40% so I don't suddenly get too low on FC.

Now to the possible algae issue. Last year I experienced a bloom, stemming from behind my light. It was BAD! During that horrible event, I noticed similar substance under my ladder and in the seams. So this year, thus far, I've checked behind that danged light and I see what looks like the beginnings of algae (yellow) and a thin line of it in the seams of my ladder. I slammed my pool on opening back in May and my FC has not gotten any lower than today's reading at 5. I test every 5 days and it generally sits around 7 depending on how hot and sunny it is, but when it reached 9 I backed the SWG down and now I'm seeing "stuff" in the light again. I hate that &^$#*& light. Its the bane of my pool. Yes I've read the article. I really don't know what to do if I'm constantly running a high FC and still getting this issue. I felt like my overall water chem has been really good this year. :'(
 

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Does your pool pass the Overnight Chlorine Loss Test?

When you did the SLAM Process in May did you follow the Mustard Algae directions and after the SLAM Process was completed raise your FC to Mustard Algae level for 24 hours?
In May, yes.

I will do the over night test tonight and see. Right now, since I turned my SWG up, its FC=6. I turned the SWG to 0%. I will let you know how it ends up in the AM.
 
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ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Ok, I just tested it and my FC is 5. It was 6 last night. So I should be ok right?

But that still doesn't solve my dilemma with the pool light and stuff trying to grow within it. Have you heard of anyone maybe adding a chlorine puck behind it?

And the other question I have is my SWG cell...that blue white build up - how can I reduce that? Is it pH, CA, or TA that causes that build up? If its CA then I'm out of luck because our water is quite hard here. Just curious. I don't want to use muratic acid if I can keep from it because I want to extend its life, not end it.

I appreciate all the help here. Being somewhat new to pools I just don't know what to expect with my pool that is normal versus what might be wrong. It seems everyone here has a trouble free pool and then there's me, struggling. Or I am? Maybe all the stuff I'm confused about and seeing with my pool is normal given the type of water I have? Still learning.
 

duraleigh

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Keep your focus on fixing one thing at a time. You bring up so many issues I cannot decide which to respond to. Let's solve your algae issue.

The chances of you having mustard algae are slim to none. It grows on the pool walls and floors on the SUNNY side of your pool......not behind your light niche. So, whatever is growing back there can not grow in the presence of adequate chlorine. If you are brushing and cleaning behind the niche with goggles and a snorkle (really?) that is wa-a-ay overkill. The niche should stay free of organics for months if you are keeping adequate chlorine in your pool.

What does your pool water look like? Can you post a pic?
 

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Keep your focus on fixing one thing at a time. You bring up so many issues I cannot decide which to respond to. Let's solve your algae issue.

The chances of you having mustard algae are slim to none. It grows on the pool walls and floors on the SUNNY side of your pool......not behind your light niche. So, whatever is growing back there can not grow in the presence of adequate chlorine. If you are brushing and cleaning behind the niche with goggles and a snorkle (really?) that is wa-a-ay overkill. The niche should stay free of organics for months if you are keeping adequate chlorine in your pool.

What does your pool water look like? Can you post a pic?
1592746870832.png
 

duraleigh

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You pool looks very nice. I see no indication of cloudiness. If you looked inside your niche now, do you think you would see things growing in it? Don't do it......I am just wondering if it is forming quickly in the niche in that otherwise nice looking pool water
 

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
You pool looks very nice. I see no indication of cloudiness. If you looked inside your niche now, do you think you would see things growing in it? Don't do it......I am just wondering if it is forming quickly in the niche in that otherwise nice looking pool water
So the below pix are from May when I opened it up. The water wasn't cloudy but this is what I saw when I opened it. Last year, this was WAY bad and thick with yellow stuff. I was told by a pool company (this is prior to finding this site and using the test kit) that it was mustard algae. It did cloud my pool up last year and it was a complete pain to get rid of. So now, because of the event last year, I'm extremely diligent about opening this up. I did so earlier this week and found just the beginnings of that gunk that you see in the photo. The light and the ladder are in direct sunlight. The are not ever in the shade. These are the only two places I ever see the yellowish residue so I brush regularly and open that danged niche often so I don't have last years event happening again. I can't be the only soul here that deals with this, but if I am then so be it. Can I put a chlorine puck in the niche and then close it up? Its so frustrating.
1592771567649.png
1592771586266.png
 

duraleigh

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Don't put the puck in there.......it's too acidic for the metal. I would suggest a small syringe (30ml) of 100% bleach about every two weeks or so. find a little hole to get it behind the fixture and there should be no need to remove the light....perhaps just loosen that top[ screw to give you an insert point.
 
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ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Don't put the puck in there.......it's too acidic for the metal. I would suggest a small syringe (30ml) of 100% bleach about every two weeks or so. find a little hole to get it behind the fixture and there should be no need to remove the light....perhaps just loosen that top[ screw to give you an insert point.
I'll give that a shot. Pun intended. ;)

Thanks for the help!
 

duraleigh

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I like that pun! I think you will have pretty good success.....you are VERY aware and I know will keep an eye on it.

Next you mention CH (you have very hard water) but you don't say how much. Could you perform the CH test with that nice kit and post the result? Comments to follow.
 
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ajup2it

Well-known member
Sep 3, 2019
125
Indiana
I like that pun! I think you will have pretty good success.....you are VERY aware and I know will keep an eye on it.

Next you mention CH (you have very hard water) but you don't say how much. Could you perform the CH test with that nice kit and post the result? Comments to follow.
My fill water is this:
TA = 240 (This is why I struggle to get it to 80!)
CA = 200 (it was 300 last month? WTheck?)
pH = 8.0

Current pool test
FC 5.5
TA 110
CA 375
pH 7.4
CYA 80
 

duraleigh

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You are okay on CH. Suggested range is around 250-400, I think, and you are right in the middle. With the rain you get in Indiana your CH should stay fine all summer.

Now, TA. Lowering TA can be long and laborious but actually very satisfying to do. Frankly all your numbers look pretty darn good except TA so let's bring it down to 60-80 (and keep it there.....it'll require some effort but you spend a lot of time taking care of your pool now so I think you'll be OK with a little more.)

Start by reading the article in Pool School Lowering TA it is an add and repeat sort of thing until you get the TA where you want it. You may need a gallon or more of acid but it will lower your TA. Post back if it doesn't make sense.
 

ajup2it

Well-known member
Sep 3, 2019
125
Indiana
You are okay on CH. Suggested range is around 250-400, I think, and you are right in the middle. With the rain you get in Indiana your CH should stay fine all summer.

Now, TA. Lowering TA can be long and laborious but actually very satisfying to do. Frankly all your numbers look pretty darn good except TA so let's bring it down to 60-80 (and keep it there.....it'll require some effort but you spend a lot of time taking care of your pool now so I think you'll be OK with a little more.)

Start by reading the article in Pool School Lowering TA it is an add and repeat sort of thing until you get the TA where you want it. You may need a gallon or more of acid but it will lower your TA. Post back if it doesn't make sense.
Well actually it just dawned on me. I had tested the tap water in the house where the water softener actually works to soften the water. I will test the tap OUTSIDE. And we're done getting rain it seems. It was supposed to storm several times this week and we got not one single drop. I hope we get some rain tonight because I really need to fill my pool, which will raise my TA back to 140 again, minimum. I have yet to back wash and rinse. If I do that I will definitely need to fill.

I've done what has been suggested here for TA. I've been through 2 gallons of muratic acid this summer already in just getting it down to 100, only to have to fill the pool again with tap due to lack of rain. I'm not sure (unless we finally get rain) that I'm going to be able to get it below 100. :(
 

duraleigh

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I'm not sure (unless we finally get rain) that I'm going to be able to get it below 100.
Well, of course you are. The process is NO different from going 140 to 100. Why do you think below 100 will be harder?

Backwash and rinse if your psi exceeds 25% of normal. What is normal psi? (directly after backwash) What is psi right now?

only to have to fill the pool again with tap due to lack of rain
That's a FOREVER thing. Just like adding FC......you have to add acid if your TA is continually rising (as when you add refill water) That's no big deal......just work with it......you are going to be rewarded with a very manageable pool that you can swim in whenever you want........crystal clear, too.
 
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ajup2it

Well-known member
Sep 3, 2019
125
Indiana
Well, of course you are. The process is NO different from going 140 to 100. Why do you think below 100 will be harder?

Backwash and rinse if your psi exceeds 25% of normal. What is normal psi? (directly after backwash) What is psi right now?

That's a FOREVER thing. Just like adding FC......you have to add acid if your TA is continually rising (as when you add refill water) That's no big deal......just work with it......you are going to be rewarded with a very manageable pool that you can swim in whenever you want........crystal clear, too.
I feel like I'm never going to get below 100 because by the time I get to 100, I need to refill my pool again and the TA goes back to 140 so I never get the chance to get below 100. My fill water (outside) is TA - 270, pH above 8.2 and shockingly (I wonder if our community complained about hard water because it is less than it used to be) CA - 200 (outside). Last year I swear is was near 400. Something has changed.

PSI is never above 10 where I run my pump speed. Even if I ran it at max i only gets to 21. I was told by the pool company to backwash and rinse weekly. I gather this is incorrect as well?

Its supposed to be raining presently, but I have nothing but sunshine and white billowy clouds. Maybe it would be okay to leave the pool cover off overnight in hopes of rain??

1592862214931.png
 

duraleigh

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Sure, I would leave the pool cover off from time to time anyway. Disregard weekly backwash......don't waste the water......use the 25% rule.

If you want, you can construct a drain from your roof gutters into the pool. Free, reasonably easy if you're hand and guaranteed to work. Will bring down your TA and CH.

JohnT lives in your region and his TA is really high, too, I think.....maybe 250-300. He deals with it nicely so perhaps he can post up or you could send him a PM
 
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