Numbers are ok, but algae lingers...sort of...Help

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
Good morning all
For 2 or 3 years, I've had my pool understood and under control thanks to TFP and its teachings. I thought that I knew my pool, and that we had a good relationship.

About 2 months ago, some green stains appeared on my walls and on some parts of the floor; I opened a different thread for it and got help there. Despite 2 SLAMS, the stains remained, so I went in with a kitchen sponge, yes, and scrubbed everything. Cool.
My FC remains higher at 12, than it should be, and the green stains have returned. Despite brushing every other day, the brush goes right over them as if nothing. The brush will remove "normal" algae, but not these stains. My FC has been slowly coming down from the last SLAM 2 weeks ago, and I stress that the water has been and remains crystal clear. I haven't been able to measure my ph since before the SLAM, so I've been letting the FC drop to 10. In doing so, I brush a small amount of algae of the floor.
**Note. I started the slam without bringing the ph down to 7.2 since I wanted to kill those stains right away. So I just took FC to slam level, and poured 10 or 12 ounces of MA before just as a precaution. My purpose for the slam is to get rid of those wall/floor stains; the rest of the pool looked and looks perfectly fine.

Saturday's numbers: FC 14, CYA 60, Temp 80, TA 60, CH 225.
Despite our hot temperatures down here, my FC is creeping down slowly; it was 12 this morning.
So. I'm torn. My FC has been coming down very slowly, and of course algae is getting brushed.

I feel like I've lost control of my pool, despite the daily reminder of crystal clear water and numbers that appear normal (except ph that I haven't measured since the last SLAM).
My thought: KEEP BRUSHING and let the FC go down to 10 so that I can get an accurate ph reading and have a complete set of numbers. And then maintain the normal weekly maintenance. Does that sound smart? However, the stains remain, so I will have to SLAM yet again...
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,640
SW Indiana
Any chance you have copper in the pool? Cheap algaecides, alternative “sanitizers” and corroded heaters are common sources.
 

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
Thanks John
You had suggested copper in the other thread..
I haven't used algaecides or sanitizers, and I don't have a heater. I can say that one of my my well water sprinkler heads does put a small amount of well water in the pool, but I would assume that it's not significant.
Wait. That head is near the deep end, and that is where most of the staining is happening. Hmmmm.

However. I scrubbed the walls 2 or 3 weeks ago BUT I haven't used the sprinklers in that time because of rains. Could it be that the copper remains in the water???
Dang.
 

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
GM. This morning, FC is at 12, and the water is looking slightly murky and I brushed a lot more algae.
Do I have to just sit patiently until FC = 10 so that I can measure the ph, then lower it to 7.2, and then SLAM? Even if I keep brushing more and more algae?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
12,998
Northern NJ
It would be helpful to log all your tests results in PoolMath.

What is your CYA?

Lowering the pH before raising the FC makes the chlorine more effective. You slowdown and handicap the SLAM Process if you don’t adjust the pH.
 

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
It would be helpful to log all your tests results in PoolMath.
What is your CYA?
Lowering the pH before raising the FC makes the chlorine more effective. You slowdown and handicap the SLAM Process if you don’t adjust the pH.
THanks ajw..Yes, I know that I have to lower the ph before the slam, but it's "weird" for me to now sit and let the pool get worse so that FC drops, so that I can then test ph, and then begin the SLAM.
My CYA is 60. The OP has the latest readings.
 

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
Hello all
In another thread I mentioned that some of my walls have these green-ish stains that might be copper according to some of you. Because of those stains, I've been in a perpetual state of SLAM and close-to-SLAM FC levels. My numbers have been these for the last 2 months: CYA 60 or 70, CH 275-300, and a TA 70. My FC has been above 16 for all of that time. I completed a SLAM 2 weeks ago, and I've been letting the FC go down to normal levels so what I can measure ph and return to normal state. However, when I brush every day or every other day, I continue to remove a slight amount of algae. The water is crystal clear, and I cleaned the cartridge filter a week ago.

So. How can I let the FC drop to below 10 measure the PH if I brush algae off every other day? This morning, FC was 18, and the water temperature was right below 70.

Prior to this I had tfp methods under control, but I feel that I've been constantly fighting some algae, high FC, and an unknown ph level, but with crystal clear water. How should I proceed?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
n15, I see you're picking-up on this thread after a break since 7 Nov. If any of your other threads are active (SLAM) I don't want to confuse things here by adding recommendation to this thread. If we need to combine, let us know.

Depending on your water temp, the FC should fall on its own. That's a waiting game. Not worth trying to force it down. If it's been a while since you last tested the pH, I would validate it before starting a new SLAM.

As for the apparent algae and staining, they may be related or may be from two different items. So you have two paths to follow:
1 - Test the stains. Removal with a chlorine tab rubbed on the area indicates organic stains. Changes from a Vitamin C tablet indicate iron. Rubbing dry acid can confirm if it's copper. Magic Jack's also sells stain ID kits if you want to go that route. But you need to know what type of stain you are battling.
2 - As for algae, it has to be completely killed/removed before worrying about stains. The SLAM Process is pretty clear, but as a reminder, once you validate the pH, confirm the CYA and keep the FC adjusted to the proper SLAM level noted on the FC/CYA Chart. Again, I haven't been to your other threads, but hopefully you've addressed any unique algae hiding places such as behind the lights, drain covers, hollow steps/ladders, or anywhere else algae can hide, otherwise it will return. Only after you pass the SLAM should you worry about stain treatment.

It is odd that after completing a SLAM just 2 weeks ago you appear to be brushing algae, so additional info may need to be exchanged to get more details. But we'll work with to try and help.
 
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nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
n15, I see you're picking-up on this thread after a break since 7 Nov. If any of your other threads are active (SLAM) I don't want to confuse things here by adding recommendation to this thread. If we need to combine, let us know.
Depending on your water temp, the FC should fall on its own. That's a waiting game. Not worth trying to force it down. If it's been a while since you last tested the pH, I would validate it before starting a new SLAM.
Thanks a lot Pat.
Yes, it's ok to combine since it's all related.
While I was slaming 2 weeks ago, the stains disappeared, so that's why I've been in a perpetual state of high FC.
II think that my plan will be to SLAM, yet again, so as to kill the algae. But.
I need to let the FC drop quite a bit from 18 so that I can test ph. Won't that make my algae get even worse? Or does it not matter since I will slam anyway, so let the algae bloom away? Does that make sense?
It's not too hot here in Miami this week, and it's been cloudy for 3 days, so the FC drop will be slower than usual; my water is 70 degrees.

Once I complete that SLAM, I want to return to a normal state of regular maintenance.

Help me understand something. I've had my FC at a high level below SLAM, but much higher than recommended; it has been between 18 and 22, or somewhere in that range. Why then, have i had to brush algae almost daily? Shouldn't the high FC eradicate the algae? I know that pool chemistry is more than just FC, but that's the main sterilizer.

Again, thank you
 

Leebo

Admin
TFP Expert
LifeTime Supporter
Jul 21, 2011
9,322
Eastern Ohio
Let's start to work on fixing your problem then we'll kinda work on pinpointing all of your other issues.

To start, can you please post a full current set of test results. It'll also be helpful if you update your logs in the PoolMath App, but we can work however is easiest for you. Additionally, a photo of your water will be helpful for us to see what you're working with.
 

Leebo

Admin
TFP Expert
LifeTime Supporter
Jul 21, 2011
9,322
Eastern Ohio
I'm not seeing a SWG listed on your logs so I'm going to assume you've added bleach manually. If that's the case then it's going to take forever for your FC to drop below 10 this time of the year. I'd say go ahead and preform the pH test and let us know what the result is........I'll also do some reading as I know there's a thread somewhere that kinda describes how the chlorine alters the pH........we'll get you in the ballpark to start your SLAM.

After you do your pH test, let's clean this pool. It looks cloudy in the photo and I suspect a SLAM Process is gonna help you out. Seeing your CYA level is 70 you'll need to increase your FC level to 28ppm and keep it there. We'll help you get things cleared up then move on to setting your up for the future. (y)
 

nabril15

Bronze Supporter
May 22, 2011
420
Miami, FL
thanks again Leebo
The ph is 7.5
I have been using liquid bleach since I bought the house, but I bought powdered cal hypo a month ago, and I've used 2 or 3 scoops of it whenever I've had to add chlorine. I've been trying to phase out the liquid bleach, but when it came time to slam, I prefer to use liquid since I'm used to it and Leslie's has double stamps when you buy it on certain days, and they give you a free one after 10...