Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 4 of 4

Thread: Green algae, Sand Filter - Add DE?

  1. Back To Top    #1

    Join Date
    Jun 2014

    Green algae, Sand Filter - Add DE?

    I have a 16x32 inground pool and cannot get rid of the green algae.

    I have added tons of shock and stabilizer while running my Hayward sand filter. I was told adding a few pounds of DE could help improve the filtration. Is this true? I'm not having much luck getting rid of the green algae and I'm trying to find an efficient way, as I keep wasting time and money on chemicals without results.

    Thank you.

  2. Back To Top    #2
    Casey's Avatar
    Join Date
    Apr 2007
    SW PA

    Re: Green algae, Sand Filter - Add DE?

    You are more than likely not holding the SLAM and wasting time, money and chemicals going the Pool Store way.

    You need to SLAM (ShockLevelAndMaintain) the pool as outlined here SLAMing Your Pool.

    You also need a reliable test kit to take control of you pool and ditch the Pool Store FOREVER! Look at these kits Test Kit Comparison. The TF100 is the best kit for the money and the one the majority of us use. It will be your number one too used in your pool tool box. You will use it every day regardless.

    Also, you need to read up on the other educational material provided in Pool School:

    ABC's of Pool Water Chemistry
    Recommended Pool Chemicals
    How to Chlorinate Your Pool
    Chlorine CYA Chart
    Recommended Levels
    What is Trouble Free Pool Care?
    Overnight FC Loss Test
    What we need to know to answer your questions

    Adding DE to the filter is a last resort and finishing touch. You are not ready for that.
    I'd bet you my bikini you'll never get TFP water from a pool store!

    24' Sharkline Venture De Filter

  3. Back To Top    #3
    golfinglenn's Avatar
    Join Date
    Jul 2013
    Springfield, OR

    Re: Green algae, Sand Filter - Add DE?

    Do yourself a HUGE favor and spend a couple of hours reading through this forum (You found it, which is the first step). There are countless stories on here of your exact situation. If you do your research and follow the advice of those on here you will have a sparkling clear pool and will save hundreds if not thousands of dollars in unnecessary chemicals.

    Before you dump anything else in your pool order the TF100 test kit. When you get it do a full set of tests and post here and we will guide you from there. This is not the pool store, we won't tell you to put something in the pool that you don't need and that won't help. Don't go to the pool store and get your water tested, it won't be accurate and you could make things worse relying on their results.

    Trust in this site and it's advice and you will soon have water that looks like this:
    6500 gal above ground Doughboy with 200lb sand filter and solar panel heater. Converted from Baqua to BBB and never looking back!!

  4. Back To Top    #4

    TFP Guide
    Kiss4aFrog's Avatar
    Join Date
    May 2013
    Hudson, WI

    Re: Green algae, Sand Filter - Add DE?

    Welcome to the forum. Sorry you haven't had any luck cleaning up your pool but you've come to the right place.
    Read about the SLAM procedure it's how best to get and keep your pool clean. Have you been using the brush to sweep the pool daily to stir things up and get the green off the bottom and walls, ladders and stairs ?? Do you have lights ??

    When adding DE to a sand filter it's not a couple of pounds !!! Couple pounds and you'll clog the filter and damage who knows what in the process. The process actually calls for 1/4 CUP additions.

    Cut and paste from pool school:
    Small amounts of DE can be added to a sand filter after each backwash to improve the filtering. The first time you use DE, you need to figure out how much DE to add to your filter. After the first time, you can simply mix the full amount of DE with water in a bucket and pour that slowly into the skimmer.

    Figuring out how much DE to use

    Start by noting the PSI reading on the filter with the pump running.
    Mix 1/4 cup of DE with water in a bucket and pour that slowly into the skimmer. Remove the skimmer sock, if any, before adding DE.
    Give the system about two minutes to stabilize.
    Note the pressure on the filter and repeat the second and third steps until the pressure has gone up by one PSI. This will typically take around 1-2 cups of DE.

    The very first time you do this, you should keep an eye on the filter pressure for the next 24 hours or so. The improved filtering may quickly catch a lot of very fine particles and send the filter pressure up rapidly.

    DE is a very fine powder which can cause skin irritation and is classified as carcinogenic when breathed in. Some areas prohibit the release of DE into sewers or the environment. Follow handling precautions as indicated on the product packaging. Gardening DE, while safer to handle, has not been heat treated and therefore is not suitable for use in pool filters.
    '70s IG Vinyl 32K gal, Lazy L, Hayward SuperPump 1.5hp 120V, S240 Sand Filter W/DE
    Solar Blanket, Well Water, Borax Added, TF-100 tester. May 20 - opened for summer
    1979, 275gal Conway Emerald Spa P-100-2, ES-2 Spa Pack, bromine floater, indoor
    TF-100, Best test kit -
    Please help keep the lights on so we can be here for others, become a TFP Supporter!

Posting Permissions

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