Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 12 of 12

Thread: My pool's love affair with algae

  1. Back To Top    #1

    Join Date
    Sep 2010
    Location
    Southern California
    Posts
    45

    My pool's love affair with algae

    I'm wondering why I keep having problems with algae. I don't seem to be able to avoid the stuff. I think it was last year someone told me that algae doesn't necessarily read and follow the rules we discuss here Thanks to TFP, I know what to do to get rid of it when I get it. That's not the problem. Here's a little recap:

    Last year I tried Fiber Clear in the filter. I thought that was the solution. I had to backwash the filter pretty much every 2 weeks, which I hated, but I thought I finally had a solution to my algae problem...until I got algae a couple of times. So, it wasn't the solution This year I'm back on DE. All the grids were also replaced this year.

    Sometimes in the past I got algae because I let my FC get too low. That's not my problem now. I'm usually running FC around 7 or 8. And I still get algae!

    Here's tonight's chemical test.

    • FC 11.0 (It's high because I had algae and added chlorine. But, when I got algae, it was around 7.5 - 8.0)
    • CC 0.5 (I know that means 0)
    • pH 7.3 (it's low because adding chlorine raises the pH and the chemical feeder adds acid. Normally it's around 7.4)
    • TA 60
    • CH 625 (It's high. People here have told me I can go with it if I keep the water balanced. I'm in California where we have a drought and empything part of the pool to refill isn't an option at the moment.)
    • Salt 3000
    • CYA 60


    This year I'm experimenting with a chemical pool cover (Heatsavr). That's something new in the water. I don't know if that affects anything? Still, I've had algae problems in years past before I started using it.

    Are pebble surfaces more susceptible to algae? (maybe it's easier to get started in one of the

    Any thoughts?
    Southern CA 30K gal Pebble Pentair WhisperFlo 1HP 2 speed Hayward DE6020 filter Paramount Debris Canister Goldline/Hayward AquaRite Pro SWG (T-CELL 15) Sense & Dispense (acid) Paramount Debris Canister Pentair IntelliBrite 5G and GloBrite Inter-Fab G-Force slide Jandy deck jets Lion head spout Dolphin Premier Cleaner Taylor K-2006 test kit

  2. Back To Top    #2
    Defgufman's Avatar
    Join Date
    Mar 2015
    Location
    Savannah GA
    Posts
    577

    Re: My pool's love affair with algae

    I'm not sure, Could it be hiding behind your pool light or behind your stairs. What does the water look like? With a cya of 60 as long as you are maintaining the target FC of 7 to 8 you should be fine.
    Inground 13,200 gal Vinyl, Pentair 3/4 hp pump, Pentair Sand Dollar filter, Polaris 280

    Pool School, Pool Math, CYA to FC ratio chart, Testing Kits

  3. Back To Top    #3
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: My pool's love affair with algae

    Pebble is not more prone to Algae, and whomever told you Algae doesn't play by our rules is simply mistaken. I'm not saying that out of anger, it's just not true, and they haven't played by our rules to find out the truth.

    Algae gets into a pool for one reason, and that is low FC. At some point you have had too low FC more than you realize. Its very likely as well that when you have had green in the past, you never fully killed it all with a good SLAM and always had some lurking and ready to spring back. I suggest a full and complete SLAM and watch the FC very closely from here out. If you do, there will be no more problems with Algae.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  4. Back To Top    #4

    TFP Guide

    Azgirl71's Avatar
    Join Date
    Apr 2015
    Location
    Sierra Vista, Az
    Posts
    2,586

    Re: My pool's love affair with algae

    I have to say, I really think you should do a full SLAM and follow it to the end. You have a good test kit. Brush ladders,lights and anything else that might be harboring algae in its crevices.
    Lisa
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

  5. Back To Top    #5

    Re: My pool's love affair with algae

    Another thing to look at....

    When I first took over the maintenance of the pool at my condo complex, I always had to keep my chlorine level at least 1ppm above what the Chlorine/CYA chart said to use. If my FC got down to the minimum for my CYA, the water would get cloudy. I cleaned out behind the light, which seemed to help a little, and I adjusted the return jets to make sure I was getting decent circulation throughout the pool.

    Then reading a thread here on TFP, I realized that my skimmer was missing its float valve (aka diverter valve). Like many in-ground pools, my floor drains are hooked up to one of the skimmers, not directly back to the pump. The float valve allows you to adjust how the suction is distributed between the skimmer and the drains. If the float valve is missing, then the floor drains get ZERO suction. (See this post for what to look for. Note that both holes in the skimmer have pipes attached, and go on for more than 6 inches.)

    So beneath the drain covers, there was plenty of light and plenty of gunk to feed the algae, and the algae was protected from the chlorinated water above. So algae was continually coming up out of the drains and getting killed by the chlorine, which was why my pool water wasn't perfectly clear. And whenever the chlorine level dropped low enough, the chlorine couldn't keep up with the algae coming out of the drains.

    Installing a float valve fixed the problem. Within an hour, my filter pressure shot way up to the point where I had zero water flow. That tells you how much crud was hiding down behind the drain covers. IIRC, I had to backwash twice that day.
    25000-gallon semi-public IG concrete/plaster pool, Triton II sand filter
    750-gallon semi-public IG concrete/plaster spa, cartridge filter
    Volunteer pool caretaker for my condominium complex

  6. Back To Top    #6
    BoDarville's Avatar
    Join Date
    Jun 2012
    Location
    DFW, Texas
    Posts
    3,840

    Re: My pool's love affair with algae

    Quote Originally Posted by Patrick_B
    Algae gets into a pool for one reason, and that is low FC.
    It really is this simple. Also second the suggestions to clean behind the pool light and around any ladders or other similar equipment.
    Gold Supporter, TFP Lifetime Supporter, 26,680 gal Plaster IGP 3.5 - 10' depth / Attached Waterfall Spa, Manually Chlorinated, Triton Sand Filter, 1.5 HP * 1.1 SF = 1.65 SFHP 1-speed Pentair WhisperFlo WF-26 Pump, 400K BTU NG Teledyne Laars Series One Heater, Polaris 360, Test Kit Comparison, Chlorine/CYA Chart, SLAMing Your Pool, OCLT
    A good test kit is an investment, not an expense.

  7. Back To Top    #7

    Join Date
    Sep 2010
    Location
    Southern California
    Posts
    45

    Re: My pool's love affair with algae

    Thanks for the thoughts. I didn't realize that after killing off the algae that something could remain behind and come back to life even with higher FC levels. I've never tried cleaning behind the light. I better give that a look (and maybe that's my motivation to replace my light at the same time, since one of the colors of the LEDs died last year).

    The water looks clear. In fact, even when I have algae, the water is fairly clear until I brush it off. I usually catch it fairly quickly and the water never gets that cloudy.

    I thought if I did a SLAM and didn't take it all the way to the shock level that it just took longer to kill off the algae. I didn't take it to the shock level this time; I just raised the level, brushed the sides, and it all seemed to go away. It looks good now, but I guess I better check behind the light and SLAM it before it comes back to visit again.
    Southern CA 30K gal Pebble Pentair WhisperFlo 1HP 2 speed Hayward DE6020 filter Paramount Debris Canister Goldline/Hayward AquaRite Pro SWG (T-CELL 15) Sense & Dispense (acid) Paramount Debris Canister Pentair IntelliBrite 5G and GloBrite Inter-Fab G-Force slide Jandy deck jets Lion head spout Dolphin Premier Cleaner Taylor K-2006 test kit

  8. Back To Top    #8

    Join Date
    Sep 2010
    Location
    Southern California
    Posts
    45

    Re: My pool's love affair with algae

    Oh, I forgot to mention: yes, the diverter valve is in place, so it's pulling from both the skimmer and the drain. Funny...I was at a friend's house a few years ago for a party and helped figure out how to get the spa going, as it wasn't working. I also found the diverter wasn't in the skimmer. She told me her pool man removed it. I told her that needs to be there so the water circulates properly and put it back in. I have no idea why he removed it.
    Southern CA 30K gal Pebble Pentair WhisperFlo 1HP 2 speed Hayward DE6020 filter Paramount Debris Canister Goldline/Hayward AquaRite Pro SWG (T-CELL 15) Sense & Dispense (acid) Paramount Debris Canister Pentair IntelliBrite 5G and GloBrite Inter-Fab G-Force slide Jandy deck jets Lion head spout Dolphin Premier Cleaner Taylor K-2006 test kit

  9. Back To Top    #9

    TFP Guide

    Azgirl71's Avatar
    Join Date
    Apr 2015
    Location
    Sierra Vista, Az
    Posts
    2,586

    Re: My pool's love affair with algae

    Yes, take it back to SLAM level.
    Lisa
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

  10. Back To Top    #10
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: My pool's love affair with algae

    Chances are, you never killed it all from what it sounds like. It won't come back with continual good FC levels if you do get it all killed. No worries there.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  11. Back To Top    #11

    Join Date
    Sep 2010
    Location
    Southern California
    Posts
    45

    Re: My pool's love affair with algae

    I finally got around to checking things, like behind the light. There was a bunch of dirt/sediment/whatever in the niche. I don't know if any algae was mixed in. It's gone now. I also cleaned out a few other places where it might lurk and then SLAMed the pool. Hopefully that takes care of things now. Thanks for the suggestions.
    Southern CA 30K gal Pebble Pentair WhisperFlo 1HP 2 speed Hayward DE6020 filter Paramount Debris Canister Goldline/Hayward AquaRite Pro SWG (T-CELL 15) Sense & Dispense (acid) Paramount Debris Canister Pentair IntelliBrite 5G and GloBrite Inter-Fab G-Force slide Jandy deck jets Lion head spout Dolphin Premier Cleaner Taylor K-2006 test kit

  12. Back To Top    #12

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: My pool's love affair with algae

    If you SLAMmed the pool, that means you followed the article in Pool School precisely and met the following criteria....
    1. Your pool water is sparkling and no signs of algae
    2. Your CC's are .5ppm or less
    3. You can hold your FC overnight without losing more than 1ppm.

    If you didn't meet all three of those criteria, you didn't SLAM.

    This thread indicates you have played patty-cake with your algae issues in the past. You must hit algae with a sledge-hammer (full SLAM value) and then maintain adequate chlorine once you have completed the SLAM.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •