Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: Borax as an algaestat

  1. Back To Top    #1

    Borax as an algaestat

    I am curious if anyone is using Borax for its alleged algaestatic properties at the 50ppm level. If so, for how long and what has been your experience? Is it effective as an algaestat and have you noticed a reduction in chlorine demand?

    I’ve looked around on this site and others but couldn’t find much user testimony on this. An old patent on the compound discusses a study from, I believe, 1983 where a number of pools were treated with Borax and, according to the patent narrative, there was a noticeable decrease in algae blooms and a reduction in chlorine demand. Is this true in the “real world?”

    Finally, for the chemistry experts here, what is the difference between sodium tetraborate decahydrate vs. sodium tetraborate pentahydrate. I “googled” the terms and “decahydrate” (in Borax) means 10 water molecules compared to “pentahydrate” (Pro Team Supreme, Bio Guard Optimizer and Endure) meaning five water molecules. What, in practice, is the difference between these two products (other than a fancy package and a huge mark up LOL)?

    Thank you.
    25,000 Gal chlorinated rubber painted pool. 175sf Hayward cartridge filter. 1 1/2 hp AO Smith pump.

  2. Back To Top    #2
    Guest

    Re: Borax as an algaestat

    Quote Originally Posted by Dive in the water's gr8
    I am curious if anyone is using Borax for its alleged algaestatic properties at the 50ppm level. If so, for how long and what has been your experience? Is it effective as an algaestat and have you noticed a reduction in chlorine demand?
    I have had a significant reduction in chlorine demand since adding borates to my pool. It has allowed me to significantly reduce the output on my SWG.
    I’ve looked around on this site and others but couldn’t find much user testimony on this. An old patent on the compound discusses a study from, I believe, 1983 where a number of pools were treated with Borax and, according to the patent narrative, there was a noticeable decrease in algae blooms and a reduction in chlorine demand. Is this true in the “real world?”

    Finally, for the chemistry experts here, what is the difference between sodium tetraborate decahydrate vs. sodium tetraborate pentahydrate. I “googled” the terms and “decahydrate” (in Borax) means 10 water molecules compared to “pentahydrate” (Pro Team Supreme, Bio Guard Optimizer and Endure) meaning five water molecules. What, in practice, is the difference between these two products (other than a fancy package and a huge mark up LOL)?
    The only difference would be the amount needed by weight to produce the same borate level in the water. The Pentahydrate form will require a bit less.
    Thank you.
    For more information I direct to two threads on PoolForum. Here and here.

  3. Back To Top    #3
    Thank you Water Bear!!!

    I was unable to search the pool forum since this feature appears to be locked to unregistered users and, as we know, it's no longer accepting new members.

    I'll be calculating my Borax requirements and posting them here for verification.
    25,000 Gal chlorinated rubber painted pool. 175sf Hayward cartridge filter. 1 1/2 hp AO Smith pump.

  4. Back To Top    #4
    Just wanted to confirm my calculation for the amount of Borax to add to my 25,000 gallon pool. Based on the two calculators I found in this site, to add 50ppm I will need 1472 oz of Borax (or just over 19 of the 4.75lb boxes). To offset the ph increase, I'll need to add 739 oz of 31.45% muriatic acid (just a little over 5 3/4 gallons).

    So it's roughly a 2:1 ratio between borax and muriatic acid (31.45%) to neutralize the ph affect on the water (?)

    The desk top bleach calculator results in a significantly lower amount of borax. Should I disregard this calculation?

    I don't plan to add all at once, maybe split into three / four additions over the next month; is this wise?

    Thank you.
    25,000 Gal chlorinated rubber painted pool. 175sf Hayward cartridge filter. 1 1/2 hp AO Smith pump.

  5. Back To Top    #5
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887
    Your numbers look right. BleachCalc is known to have a problem with it's borates calculation.

    There is no need to take a month to add the borax/acid. You could do it all in a day or over a couple of days. After you add a chunk of borax/acid give it a few hours to mix throughly with the pump on and then double check the PH. If everything is in range you can go ahead and do the next chunk right away if you want.
    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

  6. Back To Top    #6
    gonefishin's Avatar
    Join Date
    Apr 2007
    Location
    Joliet, Il.
    Posts
    389
    I just added a load of Borax and acid into my pool three days ago. I haven't been running it long enough to comment if it has hindered algae growth. The water has also been pretty chilly, so I haven't been in the pool to comment about the "feel" of the water. But I can comment to the clarity. I cannot believe at how clear and pure the water looks. It's so pretty!

    take care,
    dan
    21' Aqua-Leader AGP (10,200 gallons).
    Hayward cartridge filter and two speed pump.
    Aqua-Cal HeatWave 100k (HeatPump)
    Salt 3200ppm (in non-salt water pool)
    Borates 20ppm (slowly raising)
    Aqua-Rite SWG

  7. Back To Top    #7
    KurtV's Avatar
    Join Date
    Mar 2007
    Location
    SE Louisiana
    Posts
    270
    The "sparkle" that waterbear described was one of the things that induced me to add borates to my water. I don't see it, though. I'd like to say that that's because me water was already so clear and clean but I know that his was too.

    Oh well, pearls before swine, I guess.

Posting Permissions

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