Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 16 of 16

Thread: Algae in the filter?

  1. Back To Top    #1


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Algae in the filter?

    I'm in the midst of a prolonged "shock" cycle. Don't want to go into details. But, trying to understand the source of algae that may be gobbling up my chlorine in a clear, non-slimy, non-eye-irritating pool. Does algae reside in the filter? We use a cartridge filter with relatively low flow using a VS pump. Last time we cleaned it, a month ago, there was a huge amount of whitish residue, which I thought was from using Ca-hypo. No green or yellow. So, can algae accumulate in the filter??
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  2. Back To Top    #2
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,333

    Re: Algae in the filter?

    Algae not only can but does accumulate in the filter, but it doesn't grow in the filter. Catching stuff is what the filter is supposed to do. If you're shocking correctly then the filter will catch the dead algae and it will be cleaned out when you clean the filter.

    You really should go into details! Maybe we can help if you'll tell us how you're shocking and post a set of test results.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Algae in the filter?

    Algae will not grow in the filter. Algae requires sunlight. The inside of the filter is dark. So any algae in the filter is dead (or will be soon).
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  4. Back To Top    #4

    Join Date
    Aug 2010
    Location
    Dallas, TX
    Posts
    4,052

    Re: Algae in the filter?

    I will add, when algae is dead it turns white.
    Built in 1957 44,000 gallon in-ground, Wet Edge Primera Stone in Sky Blue, Intelliflo VF Pump, 600 lb. Pentair Triton II TR-100 Sand Filter, CircuPool RG 60 Plus SWG, TF-100 test kit
    If TFP has helped you, please click to SUPPORT TFP!

  5. Back To Top    #5


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Thanks for the input. I'm on my way to a pool place to get my CYA tested (not that they know what they're doing!) to confirm my readings which are about 35-40 (after a 60% pool refill).

    I'll post the gory details later today, but I've been shocking 2-3 times/day for 4 ,with bleach, using the pool calculator up to FC 16, CC 0.5. Last night the FC drop was from 17 to 12!!!
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  6. Back To Top    #6


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Here goes. After having trouble getting any chlorine level at all, with CYA>100, I did a partial refill around 60% on 7/10. I got CYA 30-40; pool supply gets 55-60. The water is clear, no visible algae, no dust when I brush, no eye burn, no slime. I've been shocking with liquid to FC 16, based on CYA of 40. But, I am having to add more and more chlorine twice a day, and overnight I am losing more. Last night at 11 PM, FC 17.5; this 8 AM: FC 12.0, CC 0.5.

    Now I am going to shock up to FC 24, based on CYA of 60 (?)

    Numbers on 7/16:
    pH: 7.8
    TA: 180
    CH: 240
    CYA: 40 (my test); 60 pool supply

    So, I will try to maintain FC at 24 for a couple days, and see if I still get a large overnight drop.

    Any other ideas? Thanks.
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  7. Back To Top    #7
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    Location
    SouthWest Alabama
    Posts
    22,333

    Re: Algae in the filter?

    The best thing you can do is keep after it. The more consistantly you can keep it at shock level, the better it works and the less time and chlorine it takes.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  8. Back To Top    #8


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Quote Originally Posted by Bama Rambler
    The best thing you can do is keep after it. The more consistantly you can keep it at shock level, the better it works and the less time and chlorine it takes.
    Thanks for the hand-holding. After 1.5 hrs, and a FC of only 15, I'm about to dump another 2 gallons to get to 24.
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  9. Back To Top    #9
    frogabog's Avatar
    Join Date
    Jul 2010
    Location
    Portland, Oregon
    Posts
    1,578

    Re: Algae in the filter?

    Just curious...

    Did you watch the pool store do the CYA test? Did they re-check it and did you get to look at the tube?

    I'm asking because your situation sounds like it could be an operator variable. Did you test till the dot was utterly and completely gone (your test)? The variable would be that the store tester might not have gone quite that far and a hint of the black dot remained, depending on the lighting.

    If you use the images from the Taylor website for CYA testing, a hint of the dot remains in the image they say is test end. Confuses me a bit to tell you the truth as the difference between completely obscured and mostly obscured like the Taylor image shows is ~5-10ppm in my experience.
    Where kids swim in 54 degree water, turn blue, and giggle happily cuz they got a POOL!
    Year 3 BBB -15' x 48" Intex Metal Frame - Was using (2) 1000gph Intex cartridge filters (see Full time pumping Intex). 2012, converted to 1600gph and sand filter+SWG = Sand filter love affair!
    Don't waste time and energy looking for a better value on test kits, the TF100 is the best deal around. I did the looking and spent the extra money, but you don't have to make the same mistake. Just go here: TFTestkits. I use Pool Calculator for min/max, and shocking chlorine levels.

  10. Back To Top    #10


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Quote Originally Posted by frogabog
    Just curious...

    Did you watch the pool store do the CYA test? Did they re-check it and did you get to look at the tube?

    I'm asking because your situation sounds like it could be an operator variable. Did you test till the dot was utterly and completely gone (your test)? The variable would be that the store tester might not have gone quite that far and a hint of the black dot remained, depending on the lighting.

    If you use the images from the Taylor website for CYA testing, a hint of the dot remains in the image they say is test end. Confuses me a bit to tell you the truth as the difference between completely obscured and mostly obscured like the Taylor image shows is ~5-10ppm in my experience.
    I use the "dot completely gone" method, which gives lower CYA, and lower shock levels, which have not worked. The lady at the store uses a device that has the dot on a little handle, which she pulls up until she can just see the dot. So it works in reverse; she got CYA 55-60, which results in higher target level of FC for shock. I'll try that, because with my numbers, things are getting worse, not better.
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  11. Back To Top    #11


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Quote Originally Posted by JasonLion
    Algae will not grow in the filter. Algae requires sunlight. The inside of the filter is dark. So any algae in the filter is dead (or will be soon).
    Please have a look at my last posts, which include the details of my test levels, etc. I'm about ready to call the dump truck to fill the thing in.
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  12. Back To Top    #12
    frogabog's Avatar
    Join Date
    Jul 2010
    Location
    Portland, Oregon
    Posts
    1,578

    Re: Algae in the filter?

    I think you're right. The degree of accuracy on CYA test is +/- 10ppm anyway. The variation you're describing makes sense then.

    +/-10ppm CYA doesn't always make a whole ppm difference in minimum and target (according to the calculator), but it always makes a difference for shock level. Missing shock level by even 1ppm is a whole different category than missing target by 1ppm. Shock level is much more important to make sure you're maintaining enough to do the job properly.

    Don't give up, you're doing fabulous. The fact that you've realized you might not have hit shock due to CYA variation before you posted is awesome.
    Where kids swim in 54 degree water, turn blue, and giggle happily cuz they got a POOL!
    Year 3 BBB -15' x 48" Intex Metal Frame - Was using (2) 1000gph Intex cartridge filters (see Full time pumping Intex). 2012, converted to 1600gph and sand filter+SWG = Sand filter love affair!
    Don't waste time and energy looking for a better value on test kits, the TF100 is the best deal around. I did the looking and spent the extra money, but you don't have to make the same mistake. Just go here: TFTestkits. I use Pool Calculator for min/max, and shocking chlorine levels.

  13. Back To Top    #13

    Join Date
    Nov 2009
    Location
    MS Gulf Coast- Katrina Survivor - BP Hater!
    Posts
    55

    Re: Algae in the filter?

    How's it going? I'm curious because I'm going thru the same situation. After 4 days of shocking a clear pool and still loosing fc at night, I've moved up to Mustard Algae shock level this evening. I'm also looking for the 1 ppm loss and .5 tc. Hope we find it soon.
    15,000 gal Sun Fiberglass, Glass/Lexan/Aluminum Enclosed Room, 1.5 hp Pentair Whisperflow Pump, Triton 100- 600# Sand Filter, Heat Siphon Heat Pump, 3 Dbl. Seats w/8 Jets, Waterfall, 8' Interfab Slide, Pentair SAm Spectrum Amerlite Pool Light, Stenner MHP5 Chlorine Pump, Kreepy Krauly Vacuum, Bleach, 50 ppm Borates, TF 100 Test Kit

  14. Back To Top    #14


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Quote Originally Posted by captjohn
    How's it going? I'm curious because I'm going thru the same situation. After 4 days of shocking a clear pool and still loosing fc at night, I've moved up to Mustard Algae shock level this evening. I'm also looking for the 1 ppm loss and .5 tc. Hope we find it soon.
    Finally, after 3 days shocking to FC 24 (CYA 60), my OCLT was 1, CC: 0. I was going to continue for another day, but today I found a significant plumbing leak, so I'm having to run the pump at really low speed, until it's fixed in the AM.

    I'm still concerned because during the day, full, strong sun, My FC has gone from 22 at 8 AM, to 11 at 4 PM. I've not added any more bleach today, and will do another OCLT, and keep my fingers crossed. During those 3 days I was burning through around 8 gallons of bleach/day. Argh!
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

  15. Back To Top    #15
    pepsiholic's Avatar
    Join Date
    May 2009
    Location
    Fairmont, WV
    Posts
    362

    Re: Algae in the filter?

    If I'm not mistaken your chlorine during the day at that high of a shock level will go down very quickly like that. It's the OCLT that you need to pass and it looks like you did, but it won't hurt to do it again. When I shocked my number was 22 also, but by late afternoon it was down to about 11, let it drift down the next day to about 6 (my target number) and it has remained a steady six during the day by bumping it up to about 8 every evening.
    24 x 52 Round AG Outback Empire Pool 13,500 gal.
    1 HP Hayward Power-Flo pump w/Hayward 18" 150lb. sand filter
    TF-100 test kit & SpeedStir
    Wanda the Whale Vacuum

  16. Back To Top    #16


    Join Date
    Jul 2011
    Location
    Stockton, CA
    Posts
    63

    Re: Algae in the filter?

    Quote Originally Posted by pepsiholic
    If I'm not mistaken your chlorine during the day at that high of a shock level will go down very quickly like that. It's the OCLT that you need to pass and it looks like you did, but it won't hurt to do it again. When I shocked my number was 22 also, but by late afternoon it was down to about 11, let it drift down the next day to about 6 (my target number) and it has remained a steady six during the day by bumping it up to about 8 every evening.
    That's encouraging. I was getting very depressed over this. BTW, my pool has always been clear, but for a bit of green on the grout between tiles leading into the skimmer, which is always in the shade, and under a couple floats on the Polaris feeder hose.
    22,500 gal, in-ground, plaster, Intelliflo VS 3050 pump, Sta-Rite 400 sq. ft. cartridge filter, solar panels on roof

Posting Permissions

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