Mustard Algae

[Bfassler]

Wanted to get you experts' thoughts on this before I dump a bunch more bleach in my pool. We've noticed over the past few weeks that there seems to be a bunch of what looks like dust in the pool bottom, especially on the slanted sides where the deep end goes down. The water is clear, the bottom and slanted sides just start to look "dim". When I take the brush to it, I get clouds of brownish greenish stuff, that brush off. Then we get it all cleaned up, and a week later, it is there again. It is NOT happening on the fully vertical walls. Just the slanted parts and bottom. We've had a guy doing siding work on our house, so at first we thought it was sawdust floating into the pool. But he's working in the front now, and it's still happening.

I have SLAMmed the pool. I am now considering upping it to mustard algae level, but I've never dealt with mustard algae before, so I wasn't sure if this is it. It doesn't LOOK like algae to me, it just looks like something, like dust, is coating those parts. I wish I could send pictures, but it's been pretty minimal since I did the SLAM. I still see a bit of the poof when I brush, but I can't catch it in a video, it is so minimal.

Any advice?

 

[duraleigh]

It's algae. Possible live or possibly dead "carcasses" from the live algae you can't see. The only solution is to SLAM. Most people fail to follow the SLAM article and never fully clear their pool......when did you SLAM?

 

[Bfassler]

I started it Sunday. We passed the test last night. I haven't upped to the mustard algae level yet though.

 

[Jewlry]

Following this as I have the same issue it seems every year. When I brush it with a pool brush and it looks like you said, dust. My water is also totally clear (salt water) and the 'dust' will come back the following day usually. I just keep brushing it. It is only on the bottom of my pool in spots. But as I said, I do get it every year. Nothing major, but I was figuring it may be algae of some sort. I'm getting ready to close the pool soon and need to find out what is the best way to close a salt water pool. This is my first year with salt water and LOVED it!. I normally just dump a couple of gallons of bleach in the pool and cover, but not sure if it's the same with salt water.

 

[Bfassler]

Well, I just added 5 more gallons to bring me up to the mustard algae level. Hopefully this only takes 24 hours.

 

[duraleigh]

Jewlry and erik k,

Please start your own thread. This is bfasler threads and it gets incredibly confusing when you ask your questions on top of his.

bfasler,

Your description doesn't sound like mustard algae to me and you are certainly not slamming. the 5 gallon chlorine dumps are not what we teach. I would refer you again to the SLAM article to help you clear your pool.

 

[Bfassler]

duraleigh, what am I doing wrong? I used the pool calculator and I have a Taylor test kit that I've been using for years. Here's what I did.

My FC level was at 3.5-4, and always has been. CYA was 40, PH was at 7.4, CC was at .5, before SLAM. I SLAMed my 27k salt water pool with lots of gallons of bleach to get it up to 16 and did the overnight test and passed after 2 full days of SLAMing. I did the brushing, vacuuming, etc.

Once I passed the OCLT, I went to work. When I got home, my FC was at 14. I added 5 jugs of bleach to get me to 24 FC (pool math shows this level is needed for my pool) for MA. It was still at 24 this morning when I tested. I am now running everything in the pool, brushing and vacuuming again.

What did I do wrong? Please answer asap, as I thought I was understanding this. and TIA.

 

[Bfassler]

Not sure if this should be a separate thread, but, I have struggled with mustard algae this year as well...

First, a couple questions:
- Does MA show up on the CC test? I've had the dust all this year, and even after brushing it up, I would still get 0.0 CC.
- I saw somewhere (here?) a different FC minimum for MA. It is 3 to 4 ppm higher than the minimum I was watching for years. What is this about? Do you target the higher number once you've had MA?

For over a year we've had the dust (FYI...we don't winterize pools here in HI). I always thought/hoped it was pollen, but after a slam (@ regular slam levels) it would reappear after several days. First on walls, then slowing forming drifts on the bottom.

A few weeks ago I decided to slam for MA for the first time. Brought it up to MA slam level, and after a couple days dropped robo-vac, hoses/head, brushes/nets, toys, everything I could think of, into pool overnight when at slam levels. Brushed daily. There's no ladders or lights, just 3 plaster steps and a steel handrail going in. Pump ran 24H for seemed forever, nearly a week. Passed the OCLT 2 nights in a row (but, does MA show up on a CC test?).

Since this last slam, it was gorgeous. As sparkly clear as it's been in a long while. For a couple weeks. Then, today, on a swim, I see a little bit of dust at the bottom. Then, check walls, brush, and sure enough, its back! Its minimal, but, I thought I was done with it! I vac'd to waste, then brushed, and will vac to waste again tomorrow.

Here's the numbers:
This evening:
FC 7.5 (hours after adding 2 gallons 10% following "discovery" swim...but I hadn't been watching the MA minimum just the regular target which is below the MA minimum!)
CC 0.0
2 days ago:
pH 7.5
TA 70
CH 225
CYA 30

I'm dreading another MA slam, and certainly don't want to do it the same way if it was wrong last time, or if I'm supposed to be following a higher MA FC min/target once done.

Is there any hope that the higher MA FC minimum will take care of what has returned? Or, what do I do with that MA FC number? Is another MA slam imminent?

Thank you!

Eric, I will also be following your thread, because I too hover around 0 - .5 CC. Which I thought was ok.

 

[Bfassler]

Following this as I have the same issue it seems every year. When I brush it with a pool brush and it looks like you said, dust. My water is also totally clear (salt water) and the 'dust' will come back the following day usually. I just keep brushing it. It is only on the bottom of my pool in spots. But as I said, I do get it every year. Nothing major, but I was figuring it may be algae of some sort. I'm getting ready to close the pool soon and need to find out what is the best way to close a salt water pool. This is my first year with salt water and LOVED it!. I normally just dump a couple of gallons of bleach in the pool and cover, but not sure if it's the same with salt water.

Will be following your thread!

 

[beautifulpool]

Following this as I have the same issue it seems every year. When I brush it with a pool brush and it looks like you said, dust. My water is also totally clear (salt water) and the 'dust' will come back the following day usually. I just keep brushing it. It is only on the bottom of my pool in spots. But as I said, I do get it every year. Nothing major, but I was figuring it may be algae of some sort. I'm getting ready to close the pool soon and need to find out what is the best way to close a salt water pool. This is my first year with salt water and LOVED it!. I normally just dump a couple of gallons of bleach in the pool and cover, but not sure if it's the same with salt water.

My pool has had mustard algae before. And my pool has also gotten sprinkles of “Dust” like droppings that tend to easily brush away (not stick to vertical sides like algae) Bushes or trees and stuff growing close by, showers that polleny (a word? ?) stuff in water..... especially fall and spring happens more...

 

[Bfassler]

My pool has had mustard algae before. And my pool has also gotten sprinkles of “Dust” like droppings that tend to easily brush away (not stick to vertical sides like algae) Bushes or trees and stuff growing close by, showers that polleny (a word? ?) stuff in water..... especially fall and spring happens more...

I wish there was some easy way to know the difference. I can say, I have CC at .5 or lower the whole time, and it does not seem to happen on fully vertical sides, only slanted sides. So maybe it is pollen. We don't have any trees directly around our pool, but the neighbor has one large river birch that kind of overlooks it. We get leaves from it all summer long.

 

[duraleigh]

I started it Sunday. We passed the test last night.

I guess you mean the OCLT which you can only pass in the AM....not the PM.

Secondly, why do you believe you have mustard algae?

Last, you may be doing better on the SLAM than I think but you have yet to report the three items it takes to complete the SLAM..

I suggest you ignore treating for mustard algae for now (but i guess you have already started) and confirm that you meet the three criteria for the SLAM. Is your pool water currently crystal clear with NO SIGN of visible algae?

 

[beautifulpool]

I wish there was some easy way to know the difference. I can say, I have CC at .5 or lower the whole time, and it does not seem to happen on fully vertical sides, only slanted sides. So maybe it is pollen. We don't have any trees directly around our pool, but the neighbor has one large river birch that kind of overlooks it. We get leaves from it all summer long.

In my pool, algae (if not caught quickly) it’s hard to describe - can almost look like it’s actually “growing into” the plaster....
Where-as the pollen will fall -more like dusting -and I’ll see it on slanted sides or bottom- but easily comes up with brush or pool sweep... algae more Stubborn—more on straight vertical sides...don’t know if that helps at all ....I have learned thru TFP, it’s possible to have algae, even if you can’t see it yet

 

[Bfassler]

I guess you mean the OCLT which you can only pass in the AM....not the PM.

Secondly, why do you believe you have mustard algae?

Last, you may be doing better on the SLAM than I think but you have yet to report the three items it takes to complete the SLAM..

I suggest you ignore treating for mustard algae for now (but i guess you have already started) and confirm that you meet the three criteria for the SLAM. Is your pool water currently crystal clear with NO SIGN of visible algae?

So I did say above that my CC has stayed at .5 or below. Also, my water has always been clear. When I said we passed OCLT Monday night, I meant that we met the criteria on Tuesday morning, after that night before. I'm sorry if I wasn't super clear on that.

I mentioned the reasons above that I thought I had mustard algae in my original post:
"The water is clear, the bottom and slanted sides just start to look "dim". When I take the brush to it, I get clouds of brownish greenish stuff, that brush off. Then we get it all cleaned up, and a week later, it is there again. It is NOT happening on the fully vertical walls. Just the slanted parts and bottom. We've had a guy doing siding work on our house, so at first we thought it was sawdust floating into the pool. But he's working in the front now, and it's still happening."

 

[Bfassler]

Here is a pic of my pool currently. It looks perfect and no sign of the dust poofs when I brush.

I wish I had a before but it was just a coating on the parts of the pool I mentioned above.

 

[duraleigh]

So, it sounds like your pool is clear with no visible signs of algae (you don't brush up any more "dust", right?) .

You are done, if that's the case. Let your FC drift back down to maintenance levels and your pool should remain crystal clear the rest of the swim season. If it doesn't and the "dust" comes back, then there is a good chance you never completely killed the algae during the SLAM.

PS - disregard treating for mustard algae.......I don't think you ever had it.

 

[Bfassler]

Thank you. I hope you are right about the MA!

So, it sounds like your pool is clear with no visible signs of algae (you don't brush up any more "dust", right?) .

You are done, if that's the case. Let your FC drift back down to maintenance levels and your pool should remain crystal clear the rest of the swim season. If it doesn't and the "dust" comes back, then there is a good chance you never completely killed the algae during the SLAM.

PS - disregard treating for mustard algae.......I don't think you ever had it.