Will adding borax to 50ppm kill Mustard algae

[waterbear]

Waterbear,
here are my numbers;
TC-3.0PPM
FC-3.0PPM
CC-0.0PPM
PH-7.8
TA-125PPM
CH-175PPM
STA.-50PPM
TDS-3600PPM
SALT-2500PPM
PHOS-500

That TDS & PHOS level is kinda high ain't they?
The water has a salty taste to it.
What do you recommend?
oh, by the way, my sig."Man!,this water is cold! is just me trying to be funny.

Do you have a SWG? If so, what kind? Salt level of 2500 is below the taste threshold (and too low for most SWGs to operate well, which could be the reason for the Mustard, along with a CYA of only 50 ppm, which is also low for a SWG. Your TDS is only 1100 ppm above your salt so that is your actual TDS (which is a bogus measurement anyway). Phosphates are a non issue in 99% of cases. Mine ore over 3000 ppb!

[fuelman]

Nope, I don't have a SWG.
I have thought about one but I haven't jumped on board that train.
I have only ever added a mixture of city water and well water at the first fill, then only city water since to keep the level. Bleach, liquid Chlorine, baking soda, Muriatic acid, Yellow-out, and about 4 doses of all-in one algaecide till I found this site.
I take it that the salt level is from the bleach?
The pool has only been up and running since 8/06.
Thanks for your help

[fuelman]

BUMP for answer to above

[CarlD]

You know, you could simply take our standard route and raise your FC to shock levels and keep it there until your pool sparkles. Use bleach or Liquid Chorine for that.

First, lower your pH a bit to 7.2 or 7.3. Chlorine is more effective the lower the pH but too low has other issues.

Shock your pool with bleach until FC reaches 15ppm and keep it there, checking it twice or 3 times a day. Brush and vacuum your pool everyday.

Expect it to take a week to 2 weeks to clear. Since you haven't done this, I suggest you do this BEFORE you play with copper or bromine additives. Notice that after you use bromine, you have to use lots and lots of chlorine just to get rid of the "fix"--the bromine. IMHO, it's better to use the bleach to kill the algae.

My reason for this is we have a tried-and-true method that has worked for thousands of people. If it works, (and it usually does) then it's the easiest and most reliable way to clear your pool. If it doesn't work, then it's appropriate to seek more drastic measures, like the bromine algaecide or addressing the TDS or phosphate levels.

Once the algae is dead and gone and your pool is sparkling THEN you should add PolyQuat to inhibit further growth. It's sometimes called Mustard Algaecide, or black Algaecide--whatever. Look at the ingredients. The SOLE active ingredient should be Poly....<something long>..... 60%. Whatever they call it, if it's Poly....60%, that's PolyQuat.

If it were me, I'd raise the pool to 15ppm, add the entire quart, wait 48 hours, then check the FC (it will have dropped ALOT) and then shock again to 15, and consider it done. If it were me.

You can swim in the water at that level, but wear old bathing suits because they will fade.

[Tredge]

Borax "Helps" and in my experience it does a great job. Certainly better than all the algecides I've dumped dollars into in the past. I dont need to keep insane levels of chlorine anymore since 50ppm borax.

But thats all it does. Helps.
Chlorine, proper PH and CYA levels are what does the heavy lifting and if you don't have those stable at least twice a day all the borax in the world isnt going to keep the algae away.

My advice is to add the borax to 50ppm and get your Chlorine much much higher and KEEP it there till the algae goes away.
After that my guess is that your current chlorine levels and borax will prevent the problem from recurring.

[KirstenHW]

How does one test for Borax & dissolved solids levels? I have the Taylor kit k2006 kit.

[waterbear]

fuelman, I am confused a bit by your test results. If you don't have a SWG then why are you testing for salt at all?
I am also a bit concerned by the fact that you have no CC yet you think you have mustard algae. If there was mustard in the water you would have some CC. How was your water tested? something does not seem right.

[waterbear]

How does one test for Borax & dissolved solids levels? I have the Taylor kit k2006 kit.

Best test for borates for home use is the LaMotte borate test strips. They are far superior to the AquaChek and Protream strips.
TDS is a bogus measrement for the most part. The only way to test for it is with a conductivity meter, which is an expensive piece of equipment. Don't worry about TDS.