Mustard Algae or something else

[funnyfarm299]

We had our first pool installed last year and my family has been following the pool store's recommendations for chemicals. This year, I got tired of the over-chlorination and bought a TF-100 kit. Around the same time, we noticed a lot of brown "dirt" on the bottom of the pool. My family talked to the pool store who insists its mustard algae. I think its just dirt, since I was able to vacuum the pool floor clean and it took a couple days for it to reappear (settling, I assume).

They want to dump a special algae treatment in, I want to avoid adding more chemicals if unnecessary. It's a fiberglass pool. Tested chemicals on the 29th, FC was 31 and CYA was 80. Tested it again yesterday and FC was down to 22, CYA remained at 80.

 

[duraleigh]

From your description, I think you are seeing dead algae appearing on the floor. Dirt is grainy and you can get it between your thumb and finger and feel that. Dead algae will simply "poof" away and cannot really be captured.

Assuming it's algae, your correct path is to SLAM the pool. I would suggest you read "The ABC's of Pool Water Chemistry" up in Pool School first and then the article on how to SLAM your pool. A word of caution, if you take our advice you'll have to stay out of the Pool Store for advice or adding any chemistry. Our advice and their advice will conflict and you are left in the middle. Choose one or the other,

 

[funnyfarm299]

I'm not hopping in this time of year! It's worth noting it only appears in the curve around the deepest part of the pool. It's probably better if I just post a picture when I get home.

We have stopped using the FROG system they installed, since it's just a way for them to mark-up chlorine. Correct me if I'm wrong, but if my FC levels had been above 30 with a CYA of 80, doesn't that mean I've already been SLAMing it the whole time?

I'm going to give it a second vacuum again this weekend and see what happens.

 

[JoyfulNoise]

Question - is this your pool?

Your description seems to indicate that there is some level of democracy going on about how to operate your pool. If you own this pool, then it is yours to keep and you are the dictator - you say what does and does not get done to this pool. End. Of. Story. You are right to not want to continue with the pool store "experts" because the only thing they are expert at is parting you from your hard-earned money and convincing people to buy bottles of "magic potions" that will do nothing to clear your pool. Mustard algae exists in your neck of the woods but it has very specific and tell-tale aspects to it. There's an article in Pool School all about algae, including mustard algae, and how to get rid of it.

I agree with Dave that I really think you're dealing with algae and that you need to SLAM your pool. With your FC as high as it is, you are already at SLAM levels. But, before you dive into a SLAM, please read the Pool School articles on how to clear up a pool AND post a full set of water test results before you start so that folks here can help you. In order to get accurate water results though, you are going to have to let your FC drift back down to a normal range (below 10ppm) or else the high FC will skew some of the test results or make it hard to read some tests.

Good luck,

Matt

 

[kimkats]

You are already on the right track------getting a great test kit!

Stay out of the pool store and follow what is taught here. THAT will help your pool be Trouble Free!

Here is the link to the SLAM just in case you do not have it.

Pool School - SLAM - Shock Level And Maintain

Make sure to brush your pool often AND check around the steps and such for hidden algae.

Let us know if you have any questions.

Kim

 

[funnyfarm299]

Here's a set of test results from today. Pictures of the pool attached. I want start a proper SLAM, but since it was mentioned my tests might not be accurate, I'm not sure if I should adjust my PH beforehand. I'll be using cal-hypo 58% so I'm not concerned about Ch being low.

PH 7.8
FC 15
CC 0
CH 75
TA 90
CYA 90

 

[duraleigh]

You should reduce your CYA before you SLAM. It is quite difficult to SLAM a pool when your CYA is much over 50 ppm.

And, yes, that is almost surely dead algae.

 

[kimkats]

Did you get your test kit yet?

Can you please put your pool info. in your signature. (settings, edit signature) THANKS!

Kim

 

[funnyfarm299]

Did you get your test kit yet?

Can you please put your pool info. in your signature. (settings, edit signature) THANKS!

Kim

Test results were posted in my last reply.

You should reduce your CYA before you SLAM. It is quite difficult to SLAM a pool when your CYA is much over 50 ppm.

And, yes, that is almost surely dead algae.

It's going to be a pain to drain some of my pool off since there's no floor drain. Guess I'll ask around and see if anyone has a sump pump.

 

[kimkats]

I just wanted to make sure the test results were from YOUR test kit.

You can rent sump pumps from Home Depot or even get a cheap one from Harbor freight. It will be worth it as it will make it easier to manage your pool now and long term.

Kim

 

[Casey]

May i ask why you would want to use CalHypo? With a pH so high, you can run tge risk of clouding and, not all of the granular powder will dissolve so it sits on the bottom of the pool. Brushing will be important so it's not laying there.

Welcome to TFP.

 

[funnyfarm299]

May i ask why you would want to use CalHypo? With a pH so high, you can run tge risk of clouding and, not all of the granular powder will dissolve so it sits on the bottom of the pool. Brushing will be important so it's not laying there.

Welcome to TFP.

I have twelve pounds of it that I can't return. I'll be doing a partial drain this weekend.

 

[Casey]

Lower your pH first.