Lingering Algae

pjku79

0
Apr 17, 2015
164
San Antonio
I have been fighting a really mild algae problem for the last month and can't seem to figure out why it keeps coming back. I am looking for some wisdom here as this is only my second year.

About two months ago I had an algae bloom and went into SLAM mode. I brought it all the way up and held for several days until the water was clear and passed the overnight test. After that I slowly let the FC drop back down. I kept it a little on the high side at 7-10 ppm. It has been there for 2 months now. Over the last few weeks I have noticed slight green on my tanning ledge, so I have been brushing daily. My FC still stays at about 8 ppm. I have cleaned out my cartridge filter twice. Both times it has a green tint. All my water properties look right but I am still having algae. Any ideas.

Also, I have a dolphin pool robot which runs daily. It doesn't get the ledges or steps very well so I have been brushing those every couple days on my own. I also have my pool pump running on medium for 12 hours a day and live in San Antonio, TX

I am wondering if I need to SLAM again, but my CYA is up at 90 so I am hesitant.
 
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By running the FC slightly elevated for the CYA of 90, you would think that should suffice. I wonder though if you have any other areas in that pool where algae, even the smallest trace amounts, could've been hiding? Do you have a main drain, large light with hollow niche behind it, or separate ladder/steps not already built in the shell of your pool? Some pool covers become algae traps as well.
 
By running the FC slightly elevated for the CYA of 90, you would think that should suffice. I wonder though if you have any other areas in that pool where algae, even the smallest trace amounts, could've been hiding? Do you have a main drain, large light with hollow niche behind it, or separate ladder/steps not already built in the shell of your pool? Some pool covers become algae traps as well.
I am not aware of any areas. I have 5 led lights. I have noticed they get green on occasion. I started a few months ago spraying them out with the hose when I add more water to the pool. The rest of the pool is pretty straight forward (fiberglass).
 
It's been quite hot lately, but if your FC and CYA testing are accurate, chemically there should not be any algae unless you have very poor water circulation or had hidden algae somewhere. Based on your descriptions, I don't see that as an issue. Your opening statement about fighting algae for a month is interesting since that seems like a long time for a SLAM Process unless the pool was a black/green swamp. I don't think yours was in that same condition, so perhaps the original SLAM Process was never fully completed? You've not added anything to the water other than acid, baking soda, or salt correct? Any other chemicals or products? Do those trees (Texas Oaks I assume) drops lots of junk in the water? Also, have you done another Overnight Chlorine Loss Test since the one last month? Final question, I don't see which test kit you are using in your signature. Can you confirm please?
 
It's been quite hot lately, but if your FC and CYA testing are accurate, chemically there should not be any algae unless you have very poor water circulation or had hidden algae somewhere. Based on your descriptions, I don't see that as an issue. Your opening statement about fighting algae for a month is interesting since that seems like a long time for a SLAM Process unless the pool was a black/green swamp. I don't think yours was in that same condition, so perhaps the original SLAM Process was never fully completed? You've not added anything to the water other than acid, baking soda, or salt correct? Any other chemicals or products? Do those trees (Texas Oaks I assume) drops lots of junk in the water? Also, have you done another Overnight Chlorine Loss Test since the one last month? Final question, I don't see which test kit you are using in your signature. Can you confirm please?
Sorry I should clarify. I went through the SLAM process and brought the FC back down then a few weeks later I started seeing algae back in the pool. Not a lot, just on the tanning ledges. Basically it looks like it has a green tint on the tanning ledge. Then when I brush it you definitively see the green as the brush goes over it.

I haven't added anything other then acid. The only thing I have had to adjust is pH.

I am using the TF-100 (i think that is the right one, the one that everyone recommends on here). For FC, I have used both the basic test that comes with the pH test (alway maxed out since I've been at 7-10 ppm) and the more accurate drip test.
 
I have not done another overnight test, but could easily do it.

I was just prepping to SLAM again because it's clear I have a problem and I guess I need to get rid of the algae for good. I am just not sure why it came back.

I would assume my circulation is good if I am running my pump for 12 hours and running my dolphin daily. The dolphin circulates a lot of water by itself and runs for at least two hours. I could try to add an hour of high flow at the beginning of the day (or end if that would be better).
 

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Very good. Well, I would always use the FAS-DPD for your FC testing. The OTO is quick just to check for an overall presence of chlorine, but not accurate. Good you just re-tested. Unfortunately, yes. Since you are seeing green, you have no choice but to increase the FC to 31 and SLAM. Of course lower the pH to about 7.2 first though. Between your sweeping and the Dolphin, it's odd you saw a return in algae, but at this point your best course of action is to use the SLAM Process once again. Like my FG pool, there's not many hiding places. LED lights are out, and I have no drain. But check your skimmer and under the lid as well just in case.
 
Very good. Well, I would always use the FAS-DPD for your FC testing. The OTO is quick just to check for an overall presence of chlorine, but not accurate. Good you just re-tested. Unfortunately, yes. Since you are seeing green, you have no choice but to increase the FC to 31 and SLAM. Of course lower the pH to about 7.2 first though. Between your sweeping and the Dolphin, it's odd you saw a return in algae, but at this point your best course of action is to use the SLAM Process once again. Like my FG pool, there's not many hiding places. LED lights are out, and I have no drain. But check your skimmer and under the lid as well just in case.
Sounds good. Thanks for the advice as always. I will go dump some bleach in now to get the ball rolling.
 
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Step 1 complete: add acid to reduce pH to 7.2
Step 2 complete: dump 4.8 containers of bleach in the water and turn pumps to 100%.
Step 3 complete: brush entire pool (complements of 10 year old)
Step 4: wait patiently (the part I am not good at).
Step 5: costco run for more bleach
 
Does your costco have non-Clorox bleach? You want to avoid that brand as they add extra stuff to it. Usually your best bet is Pool Essentials from Walmart.
 
Does your costco have non-Clorox bleach? You want to avoid that brand as they add extra stuff to it. Usually your best bet is Pool Essentials from Walmart.
That is interesting. I have never heard this. This is basically what I have been getting for over a year now. I only use it when SLAMing. What extra stuff do they put in it?

 
Here is a thread on it, but basically they reduced the strength, added polymers, and even saythe Cloromax Technology is not for pools.


The pool essentials from walmart seems to be the best as it is stored inside and usually fresh. Home Depot and Lowes also cary liquid chlorine, but check the dates and avoid if it is outside in the sun.
 

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