Mustard algae battle continues!

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C

calstar

Well-known member
Feb 28, 2014
133
santa barbara, california
After a false start I restarted slam on 6/20, target is FC 20, when i get past the slam I'll raise the target to 30 for the mustard slam. Pool temp is 78f from the sun now at the highest point of the year, very high UVs, Santa Barbara latitude 34.4. I'm using over 2 gals a day trying to keep pool at or near target, CYA 50, TA 120, water is crystal clear and has been since initial brush/vacuum and am brushing daily.

Here are my readings from 6/27 but typical overall, time of readings are +- 30min and no direct sun on pool for readings at 6am or 6pm:

6am FC 17 ONCL 3 CC 0 added 2qts 10% bleach
10am FC 15 CC 0 added 3qts, a cup or so more than PM indicates
2pm FC 17 CC .5 added 2qts
6:30pm FC 15 added 3qts CC not taken

this morning FC 16 ONCL 4 CC.5 added 3qts

This is the pattern of readings over the first week of slam, CC always 0-.5, ONLC 3-4, pool drinks up the bleach, chemicals TF-100 refill kit and about a month old, using a speed stir for mixing/testing.

Comments? thanks
 
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Pics of pool, the kicker is maybe in the first pic, the mixing vial. I had to order a refill kit for the slam reagents and it came a couple of days ago, I wasn't using the new vial until this evening, the new one tested 19 FC and the old one 16(3FC difference) same sample of water, can this be the cause? I'm hoping that's it, I won't mind dumping all that bleach($16 a day) if I can move forward with the final step, at least I'll have the most sanitary pool in town. Testing in the morning for FC and ONCL will tell me more

LU7BlMA.jpg


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drain cover is removed(pump always off if I'm in it for cleaning) for slam for access as is the light, 9' deep
EhzGyDr.jpg
 
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mknauss said:
Clean the test vial with alcohol. Rinse well.
Click to expand...

I no longer will use the old vial, no reason since I have the new one. I took a reading of FC 18 at 9:30pm last night(FC 19 at 6:30pm reading so drop of 1), this morning 6:30am FC FC 18, so ONCL was 0 or 1, CC .5 As the day progresses I will know if the beach usage is as huge as it has been, still a mystery why the pool is consuming so much bleach.
 
Today will be the 11th day of slam. This is my testing for the last two days, still using a lot of chlorine during the day but CC 0 and ONCL is 1(or fractionally less), water is as pictured above, crystal clear with no debris/dead algae on bottom. I think I'm ready to elevate bleach to mustard level 30, don't know what the deal is with the high bleach consumption other than its been 80f + with the sun directly overhead. The ONLC samples were taken at 9:15pm +- in the dark and checked at 6:15am before any direct sun hit the pool, seems like valid tests for the ONLC. Top tip for mustard algae: get/use a Taylor Speed Stir, without one the mixing would be beyond tedious. Thoughts?

6/29

6:30am FC 18 ONCL 1 using (new vial) + 3cps brushed
11:30 FC16 CC0 +2qts 3cps
4:45 FC15 CC0 +3qts
9:45pm FC 17 CC 0

6/30

6:30am FC 16 CC 0 ONCL 1 (9:45pm-6:45am) +2qts
8:30 FC 20 CC 0 brushed and vacuumed , morning fog
11:45 FC 20 CC 0 +0 full hot sun
2:45 FC 16 CC 0 2qts 3cps
5:30 FC 17 CC 0 +2qts
9:15pm FC 16 CC 0

7/1

6:15am FC 16 CC 0 ONCL 1 +2qts 2cps
 
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I'm towards the end of a slam(requires FC 20) for my pool, 11 days, last few days ONLC 1, CC 0, no debris/dead algae on floor/walls, water crystal clear. During the slam I've had to add up to 2gals a day of bleach(testing every 4 hours, typically it falls from FC 20 to FC 16-17 so as per PoolMath I add 2qts+-) even though CYA is 50. Using city water in the pool.

Its been in the low 80f range with sun directly overhead, latitude is 34 so fairly intense UVs. Brushing daily, TA 120. I don't understand why this is happening, I haven't had anything like this before, is a high FC harder to maintain than my normal FC 7? Don't really want to let my FC fall back to normal and then have to add a lot of chlorine everyday so I'll keep it as close as I can to FC20 a little longer. As soon as I am finished with the slam I will shock for mustard algae at FC30. I've posted about this in the Treating Algae forum but no one hs posted info in a couple of days regarding the chlorine loss so I'm posting more specifically here. I don't know if I should bump my CYA to 60 now, if this is a UV/sun loss, in an effort to solve this or wait. Any help greatly appreciated. thanks, Brian
 
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The higher the FC the quicker it will burn off in the daytime.
Leave your CYA at 50 - at least until you have completed the SLAM Process and mustard algae SLAM portion.

At normal FC levels, pool will use 3-4 or more FC daily this time of year.
 
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I will also offer this advice. In al the testing above I did not see a pH or CH test result. It would be nice to know their history as well (not just one test) because it's very possible what you are seeing across the pool floor isn't MA at all, but organic staining and/or calcium build up. Sometimes those occur together and the stains get trapped. If that's the case, the chlorine will do nothing. If you elect to do the elevated MA increase that's fine, but once that's done and you start to let the FC ball back to normal, I would consider increasing the CYA to 60 and balance the FC to that according to the FC/CYA Levels.
 
Texas Splash said:
I will also offer this advice. In al the testing above I did not see a pH or CH test result. It would be nice to know their history as well (not just one test) because it's very possible what you are seeing across the pool floor isn't MA at all, but organic staining and/or calcium build up. Sometimes those occur together and the stains get trapped. If that's the case, the chlorine will do nothing. If you elect to do the elevated MA increase that's fine, but once that's done and you start to let the FC ball back to normal, I would consider increasing the CYA to 60 and balance the FC to that according to the FC/CYA Levels.
Click to expand...
Fill water from the city is high around CH 440, pool CH 800, I manage that by keeping a low pH, 7.2 is my target pH, did not test current pH since PoolMath says its not accurate. I had the pool covered with a removable blue "bubble" cover(cut into 3 sections for easy removal), the algae was yellow with with a bit of green tint and growing on the walls and floo. I had neglected the pool and it grew in nearly all areas, walls and bottom, under the cover, but luckily was not heavy growth, water was clear not green until I brushed the plaster. I've had it previously a couple of times and feel confident it is MA rather than staining. Yes I will start the MA and process later today and monitor the FC closely as I now know higher slam FC(20) goes down fastercompared to normal. As you suggest I'll then let it drift down to the 7 Ph range recommended by PoolMath(FC/CYA balance) for MA control/maintenance as well as bring the CYA up if testing indicates its necessary. The bubble cover will not go back on, its time for a new one anyway as this one is over two years old and not in great condition. All pool tools, hose, etc will be in pool during the 24 hr treatment.

Thank you very much for the info, Brian
 
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Look into installing a water softener and have a soft water line plumbed to the pool autofill.
A 60k grain unit would provide soft water for your house and the pool - outside irrigation should use un-softened water.

A fill water CH of 440 is high, even by California/Nevada/Arizona standards.
With the pool CH at 800, managing the pH is vital to keep your CSI in range.
Don't worry if PoolMath suggests you are out of recommended or ideal range - do what is necessary to keep the CSI in the 0.00 to -0.30 range.
Be sure to turn on Track CSI in PoolMath and enter all test results - whether they meet "recommended" or "ideal" parameters.

The pH test is invalid with FC greater than 10 - so don't test it or dose until you FC is 10 or less.
 
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