Mustard algae help

[jefferyasher]

We started noticing small piles of what looked like sand or dirt on the bottom of our pool a week or two ago, although the solar cover stayed on and we weren’t swimming so didn’t pay much attention. Because we hadn’t been swimming, we inadvertently let our FC level drop this week but corrected it. Last night we finally got in and realized it was probably mustard algae. There is nothing on the sides of the pool, and it is not slimy. It is just piles that look like sand and dissipate when brushed. The water is completely clear. We started a SLAM last night and got our FC up to 27 (tested using test kit TF-100). Early this morning the FC was still 27. I brushed everywhere to dissipate the piles (although it all reaccumulated shortly thereafter). Around lunchtime the FC is still 27. I’m stumped. What do we do?

 

[Texas Splash]

Welcome to TFP! You seem to have passed the Overnight Chlorine Loss Test, so perhaps it's not algae at all. Most times what appears to be MA really isn't. You can compare what you are experiencing to the link below. Anything in the local weather that could explain the stuff on the pool floor? What type of filter do you have? It might help if you updated your signature with all of your pool and equipment info. See mine as an example. Be sure to include which test kit you are using. For some reason your Poolmath logs aren't showing, so perhaps you can show us your latest test results here?

Mustard Algae

Today We are going to show you how you can get rid of mustard algae in your pool. By following the steps in this guide and with no expensive chemicals.

www.troublefreepool.com

 

[jefferyasher]

Thanks! We have a 24,000 gallon metric (half above and half below ground) round pool with vinyl liner, Swimpro Voyager pump, Swimpro Enduraclean Elements Filter Cartridge Filter, Rheem heater. We use the TF-100 test kit. We've had very little rain recently, so there hasn't been any weather issues. We have had pollen earlier in the spring and this appears to be different. When we run the dolphin vacuum it doesn't pick the stuff up either. Here are our current readings.

 

[jefferyasher]

Any advice is much appreciated. We passed the OCLT again last. I brushed to dissipate all the particles early this morning, and again two hours later since they had reaccumulated. I also cleaned my filter cartridge. The chemistry seems to be saying it’s not algae, but everything we see seems to be saying it is. I don’t know what to do at this point. Thanks.

 

[Texas Splash]

Odd. Short of simply taking your FC up to Mustard Algae level, I can't think of anything else other than something local settling on the water. If you elect to increase the MA level, be sure to review that link above closely.

 

[duraleigh]

Vacuum the debris into your filter. Brush as well but the filter should pick it up.

Can you post a complete set of current test results?

 

[jefferyasher]

Vacuum the debris into your filter. Brush as well but the filter should pick it up.

Can you post a complete set of current test results?

There is no debris, just the yellow/tan powdery substance on the bottom of the pool (which we are assuming is mustard algae). When brushed it dissipates into the water.

I just retested and the FC had dropped a little, so I added more liquid chlorine to take it back to MA Shock level (30).

 

[jefferyasher]

I wanted to update our experience. We are now on day 11 of battling this. Although we passed the OCLT the first two nights (as described above), I figured out that I needed to start brushing every couple hours every day long and we quickly lost chlorine during the day and overnight. We now notice less and less algae each day but it still grows back. We thought we had passed the OCLT 2 nights ago, so we raised to MA shock level and were hoping the end was in sight. But now we are still losing chlorine at night. We are so discouraged and exhausted. How much longer should we expect to have to continue SLAMing? My kids want to swim and we’re nearing the end of our pool season. I’m considering going rogue and just dumping algaecide in there.

 

[Mdragger88]

Did u raise to MA slam level & maintain it for 24hrs along with throwing all your stuff in there? Before doing so did u scrub all the places algae may hide - like light niches, under drain covers, ladder rungs/rails/cups, skimmer throats, weirs & their foam, other cracks/crevices, water features etc?

 

[Mdragger88]

Also can u post some pics of your pool?

 

[jefferyasher]

We have been at MA level for 48 hours now. I brushed the pool about 90 minutes and there are already spots grown back (two spots in attached pic). We removed steps and lights and have not replaced yet. We did put all toys in for a couple hours the first day at MA level.

 

[Mdragger88]

I don’t see anything in the pic.

 

[proavia]

Algaecide is more of a preventative - it won't eradicate algae.

Once FC falls back within normal SLAM Process levels, get in the pool and try to capture some of this debris. Smear it on a white paper towel or white paper plate. Post pics here. Let us know what the texture of the debris is.

The pH test is not valid when FC is >10.

It's safe to swim when FC is anywhere between minimum and SLAM level for your CYA based on the FC/CYA Levels.
The CYA can only be read in units of 10 as the scale on the tube is logarithmic, not linear. If CYA is over 50 and 60 or less, your CYA is 60.

 

[jefferyasher]

So should we let the FC go down? Even though I can still see algae growth? I don’t understand how algae can continue to grow when our FC has been so high for 11 days….

 

[Mdragger88]

In my Mustard Algae experience my “accumulation” didn’t change color until I reached MA slam level for a solid 24 hrs. At which point I vacuumed it to waste & it never returned. I then held normal slam level for another day or so & did another oclt @ slam level to be certain then maintained @ or above MA minimum for my cya for the remainder of the season. If you are seeing less & less accumulation, stay the course, you’re on the right path.
As mentioned above- count your cya as 60 so MA slam level is 35ppm & regular slam level is 24ppm

 

[jefferyasher]

Update: we’re at the end of day 13. After still seeing no improvement, we decided last night to let our FC come down, rebalance chemicals, and try something else. Chlorine alone is CLEARLY not working. Today (less than 24 hours) our FC is down to 21.5 and the algae has increased significantly already.

When we can, we will try to capture some and post pics of it on a paper towel.

 

[duraleigh]

Let us know how things turn out!

 

[jefferyasher]

Here is what we have….dead or alive algae?

 

[Texas Splash]

dead or alive algae?

Where you able to collect any of it? Did you do an Overnight Chlorine Loss Test over the weekend? It doesn't appear to be as dark as I would think for live algae, but also not as light (grey) as dead.