Pool guy says mustard algae, but ?????


New member
Hello to you all. I am new to forum and have finally found a place where I can find answers to my pool problems.

We opened our pool a couple of weeks ago and after using chlorine (sock-it)and the other "stuff" that we always have used, (around $150), :shock: (my better half does this), the water is still cloudy and kinda yellowish.

My husband saw the pool guy that takes care of my next door neighbor's pool on Thursday and got him to come take a look at ours. He immediately, (and I DO mean immediately) said that we had mustard algae. He said that he would bring, on Friday, three bottles of something that would rid us of it @ $25.00 a bottle. Our pool is an L-shaped, 43' long X 28' at the widest, vinyl liner, and I think it's about 40,000 gal. Anyhow, he didn't show up and the water hasn't changed since then.

I've been doing internet searches most of the day and finally found this place. PLEASE help me!!! I have never heard of using just plain old laundry bleach before, until I read comments on this site. Is that right? and how much should we use?

According to the test strips that we used, our pH is 6.8, our FC is 0.5, our TA is 80, and our stabilizer is below 0. And did I read on this site that Borax is used? What is it used for? Please direct me to the information about using those household products; I'm tired of searching and would really appreciate some direction.

I'm starting to think that we might be better off just draining and refilling, but would like to avoid doing that if there is a better solution. I need to mention too that last year some leaves got into the pool and left a pretty nasty stain that didn't come up all season long. I just know that when we get the water clear, those stains will still be there. What, if anything can we do about them?

Thank you so much for being here. Just wish I'd have found you sooner. :-D

[Edit:jjparrish: Edited for eye breaks]


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida

Welcome to the forum. Take a deep breath and focus on getting your pool issues one at a time.

Start by reading a few of the stickies in the black bar just below Trouble Free Pool above.

Particularly, "ABC's of pool water chemistry" and "BBB for beginners"

The chances of you having mustard algae are fairly slim.

Based on your test results you posted, your pH is too low by a little but your biggest issue is you have no chlorine or stabilizer (CYA) in your pool. That's a guaranteed recipe for algae to form in your pool but the chances are it's not mustard algae. Either way it can be dealt with.

You are going to need chlorine in your pool. The simplest way to get it there is with bleach. Plain old Clorox bleach is 6% chlorine and, if you choose to get your pool cleared up with help from the forum, you are gonna' use a bunch of it.

Secondly, you are gonna need a good test kit. I hope you buy mine but if you don't, the Taylor K-2006 is good and the Leslie's FAS/DPD kit is good ,too.

Once you get your kit you can begin to understand what's going on in your pool and begin to rely on your judgement and accurate results rather than the "pool guy from next door" who could be right but my bet is he isn't.

Take your issues one at a time....the first being getting your water cleaned up. we can help with the rest but you have to start slowly.


TFP Expert
LifeTime Supporter
May 30, 2007
South Carolina
Hi grits and welcome to the forum.

First, please take a water sample to the pool store for testing and post the results.

The best investment we made in our pool is a good test kit and I recomment the TF Test kit from duraleigh, link in my sig. This kit will save you $$$$ and will put YOU in control of what happens to your water :wink: No more algae w/BBB & good test kit.

If your pH is really 6.8 I'd bump it to 7.2 to 7.6 range first.

Read the two stickies Dave listed and then read Jason's sticky on clearing a green swamp here:


Using Jason's Pool Calculator, link in my sig, calculate the amount of chlorine/bleach you will need to reach shock level.

The chlorine/bleach is regular unscented, usually 6%, found at most grocery stores, WalMart, etc. or you can buy liquid chlorine at the pool store that is a higher strength, maybe 10 - 12%. But, it is all liquid chlorine. (I personally use the 6% bleach from Aldi's, but I'm not shocking my pool, either!)

Remember that it is hard to kill a pool and you will need some POP, pool owner patience for it to clear to a sparkling oasis, but it will clear! :lol:

Please list all your pool and equipment info in your sig so that we can better answer your questions.

Ask all your questions, members are here to help! :lol:


New member
Thanks you guys. Just after I posted yesterday, and read the recommended articles, we were about to leave to go to Wasmart and the pool man from next door came by. He had been to Atlanta to get some things for my neighbors's pool and had picked up some things to get ours going. It cost us a pretty penny, but at the time we figured, "What the heck". He said that it would take about a day and a half to clear up. I can tell a little difference this morning, so hopefully it'll be swim ready in a day or so. anyway, thanks to you both and I'm sure I'll be talking to you again.


LifeTime Supporter
Jun 26, 2007
SF Bay Area

Welcome to the forum.

The cost of chemicals for maintaining a pool does not have to cost very much. For example, my pool is smaller than yours at 24,000 gallons, but I probably spend only $30-$35 per month for liquid chlorine. Maybe I will have to add a gallon or three of muriatic acid to the pool during the summer season. THe winter months are even less expensive (maybe $6 per month?) I haven't had to use any other chemicals for my pool since we bought the house two years ago. AND that includes cleaning up a green pool last month (I let the pool get away from me after the water warmed up :oops: )

If you just spent $75 on the 3 bottles of "something", then you spent what I spend in two months on pool chemicals. And the $150 on opening chemicals? Yikes.

The testing strips are not accurate enough to help you to tell what is going on in your pool. You would have been much, much better off spending the $75 you gave to the pool guy next door on a good test kit instead.

It may seem like we're trying to sell expensive test kits on this forum, but we're really not. We don't care WHERE you get your test kit - just that you get one.

Good luck and we'll be here when you get back.



May 5, 2008
There are a lot of unscrupulous people out there who want to sell you magic pool chemicals that “fix” problems. More than anything they make problems.

I got a pool a few months ago and found this board at the same time. What amazed me was the difference in attitude between the guys here and the guys at the pool store. The guys here say buy a test kit and test your own water. Post the numbers and we will tell you how to read them and give you the information so you can make an informed decision about what is best for your pool.

The guys at the pool store want you to bring in your water, they test it and they sell you “stuff” that “does things” to your pool. you don’t know what the stuff is or what it does and the guys at the pool stores most likely won’t or can’t give you a good explanation.

From what I have learned in the last little bit of a lot of reading: I test my own water with a good kit and I add chlorine either to “normal” levels at 2ppm or if needed “shock” levels at 10ppm. I check PH but so far so good.

Having a clean safe pool is just that easy and I am proud I am doing it without resorting to a witches brew of weird chemicals the pimple faced kid at the pool store says I “need”!