Mustard algae, second year in a row, same time of year

[linuxninja00]

Hello fellow TFP'ers. I'm curious for opinions on my situation. I'm battling what very well appears to be mustard algae for the second time in as many years. Also at the same time of the year, early-mid August. Very positive it's mustard algae not pollen. At first i vacuumed it all up, thinking it was pollen, only to have just as much on the bottom a few days later. At this time of the year, there shouldn't be that much pollen/tree stuff... the cars here aren't yellow. Logically next step I took was SLAM and then up to mustard algae levels.... I'm still in that process as I just started yesterday, but already i've got noticibly less of anything on the bottom/walls/etc. What I'm curious of is why might I have gotten this for a second year in a row. I have lots of tree cover, probably only full sun on the pool for 3.5 hours in the top of the afternoon. Unsure if debris from all the trees is getting that into the pool. I've also got the occasional snapping turtle that likes to make its way out of the pond behind us and chill in the pool. What I've read, mustard algae can grow and survive in our normal FC amounts. I can say for certain that I've not fallen below TFP recommended amounts. I test regularly with my TFT test kit. Looking over my PoolMath logs for the summer, here's where I'm averaging test-wise:

FC - 8
CC - 0
pH - 7.4
CH - 200
CYA -50
TA - 50

Just looking for any opinions or even suggestions if I'm not doing something right. Thanks in advance.

 

[proavia]

It's possible your FC level could have fallen below minimum between testing.

Always dose for the high side of target for your CYA. And if you think dosing for the high side of target will still allow you to fall below minimum between testing, dose a couple ppm higher. It's save to swim with FC anywhere between minimum and SLAM levels - as long as you can see the entire length and width of the bottom of the pool.

 

[linuxninja00]

I've considered that perhaps my FC is falling too low, but I'm not so sure it would be.... Certainly I'm not testing multiple times a day, but I am testing afternoon/late afternoon usually, so i'd expect my loss to have happened given by late afternoon (i.e. 4pm), suns off my pool. My results at that time of day are as posted about, usually 7.5-8.0 FC.. given my CYA of 50, PoolMath says I should be 2.0-8.0 and I'm at that top range.

 

[JJ_Tex]

On paper you look good, but sometimes paper cannot explain all of the variables like heavy swimmer days, areas of low circulation, extra debris, snapping turtles (that's a new one )etc.

As others have said, bump up your chlorine. Also note that for a CYA of 50, your target is 6-8 with 4 being the bare minimum. Since your pool is telling you it needs more chlorine, shoot for a target of 8-10.

 

[linuxninja00]

On paper you look good, but sometimes paper cannot explain all of the variables like heavy swimmer days, areas of low circulation, extra debris, snapping turtles (that's a new one )etc.

As others have said, bump up your chlorine. Also note that for a CYA of 50, your target is 6-8 with 4 being the bare minimum. Since your pool is telling you it needs more chlorine, shoot for a target of 8-10.

Just double checking my understanding here... Since I'm using SWG, are my minimums actually lower? Like 3-8? Not arguing the possibility that my pool is telling me it needs more FC, just making sure I'm shooting for the right targets

 

[JJ_Tex]

Just double checking my understanding here... Since I'm using SWG, are my minimums actually lower? Like 3-8? Not arguing the possibility that my pool is telling me it needs more FC, just making sure I'm shooting for the right targets

You are correct, I missed the SWCG. I would still shoot for the higher targets. For reference, my target FC is 5 but if you look at my avatar you can see my FC is way higher at 8+

 

[Bperry]

Just double checking my understanding here... Since I'm using SWG, are my minimums actually lower? Like 3-8? Not arguing the possibility that my pool is telling me it needs more FC, just making sure I'm shooting for the right targets

Would also be super helpful to track your test results over time. Pool math has an option to track and share logs if you want to.

 

[Gardenmom]

I have been battling yellow mustard algae since mid July. We’ve had so much rain. Completed at least 2 slams, followed by the yellow mustard slams. I think I’m all clear, then let the Cl drift down, only to have to repeat the process. I thought I was all clear yesterday, and this has happened previously, the water is clear, the walls, floor and coving clean. The pool steps are not, they have yellow mustard. And this is where I pour the Cl in, about 3 feet from the return. We have a clear solar blanket that we keep on the pool when not in use, which has been most of this summer. Never had this happen with blue solar blankets. Coincidence? I’m baffled. Should I bump up the Cl above the 23 SLAM level?

 

[Bperry]

I have been battling yellow mustard algae since mid July. We’ve had so much rain. Completed at least 2 slams, followed by the yellow mustard slams. I think I’m all clear, then let the Cl drift down, only to have to repeat the process. I thought I was all clear yesterday, and this has happened previously, the water is clear, the walls, floor and coving clean. The pool steps are not, they have yellow mustard. And this is where I pour the Cl in, about 3 feet from the return. We have a clear solar blanket that we keep on the pool when not in use, which has been most of this summer. Never had this happen with blue solar blankets. Coincidence? I’m baffled. Should I bump up the Cl above the 23 SLAM level?

Your solar cover may be contaminated. Try leaving it off and see what happens.

 

[Gardenmom]

Your solar cover may be contaminated. Try leaving it off and see what happens.

Thanks, that’s what I’m thinking. Weird that the algae is only on the steps. Maybe the steps are old, not as smooth anymore. I brush them daily.

 

[Gardenmom]

Thanks, that’s what I’m thinking. Weird that the algae is only on the steps. Maybe the steps are old, not as smooth anymore. I brush them daily.

took the cover off yesterday. No mustard algae today!

 

[kellyfair]

I noticed you said you just started yesterday raising to SLAM, then raised to mustard algae level. SLAM isn’t a one and done, it’s a process. So, you may not be doing it long enough to really be algae free, which would explain why your algae returns when you let FC drop.

SLAM Process

Can we see photos of the algae?

 

[Gardenmom]

I noticed you said you just started yesterday raising to SLAM, then raised to mustard algae level. SLAM isn’t a one and done, it’s a process. So, you may not be doing it long enough to really be algae free, which would explain why your algae returns when you let FC drop.

SLAM Process

Can we see photos of the algae?

Hi, thanks for your reply. I had completed 2 or more SLAMS, passed OCLT both times then raised CL level to yellow mustard algae shock level, again passing the OCLT. The algae would reappear a few days later after Cl level drifted back to around 13. It certainly was stubborn. We removed the clear solar blanket, repeated the SLAMS and after 5 days, no algae. Must have been on that cover, as I had seen a few yellow spots upon removing. Have never had yellow algae before. Thanks to all with great advice!

 

[damdan]

hello. is it actually yellow, or kind of a yellowish green?

 

[damdan]

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