HELP dealing with mustard algae!

[shannon2014]

Got my kit in last night - these are the readings I got this morning. Please keep in mind first time testing and I have been working all night
FC 22.5
CC 11.5
Ph 7.8
TA 200
Ca+ Hardness 100
CYA 80
Still had algae on bottom of pool which I vacuumed to waste. It wasn't alot -seems to be thinning out - not as many large clump areas. Any advice would be appreciated!

[Watermom]

I really doubt that you have a CC reading of 11.5ppm! Take a look at these testing demos: http://pool9.net/K2006-vid/

If you are still fighting algae, then you need to continue keeping the pool at shock level and brush your pool while the chlorine is high. Now that we know what your CYA reading is, we need to adjust your shock level per the Best Guess chlorine chart: http://pool9.net/cl-cya/
So, your shock level will be 20ppm. And, once you get this algae bloom cleared up, you'll want to make sure you always keep your chlorine between 5-10ppm. If you drop lower than that, it will come right back. (By the way, the "best guess" chart is also available through the tab in my or Ben's signatures if you ever need it and can't find the link I put above.)

Since your CYA is on the high side at 80, only use bleach from now on. No more dichlor shock or trichlor tabs. They both have CYA in them and you don't want yours any higher.

Did you ever do the DE test to check to see if your filter is working properly?

Hope this helps. Re-do the chlorine test after you watch the videos and repost your FC and CC numbers.

[shannon2014]

retested this morning - add 3.5 jugs of bleach last night before going to work - ran filter all night - think it rained some too.
FC 43.5
CC 2
pH 8.0
CA+HARDNESS 200
TA 150
CYA 80
I have not had chance to do DE test as I worked nights all this weekend - gonna try to today or tomorrow morning. sand might be coming from yard and deck as it is not by all the input areas - just stairs. If filter needs sand changed and laterals replaced - how difficult is this? algae is now more of a brown gray color - still disappates into a cloud when brushed. Do I just need to continue with the bleach at night? Anything else I might try? So want to have kids swimming soon.

[Watermom]

Don't test your CYA daily. It doesn't fluctuate if you are only using bleach and it will only waste your reagents.

I'm going to ask Ben to jump in on this thread and see if he has any additional ideas.

Report back after you do the DE test to confirm whether or not your filter is working.

[shannon2014]

Ok I will let you know what happens. Thanks.

[PoolDoc]

Do this:

1. Go get a cheap OTO / phenol red drops kit. Also, get a gallon of Walmart *distilled* water (NOT: "spring", "artesian", "crystal clear", etc.). Use the OTO drops to test your chlorine. Tell me what you see -- the color result may not match anything on the test block.

2. Watch ALL the Taylor instructional videos:

http://pool9.net/tk-guide/
http://pool9.net/tk-interfere/

See if you notice any differences between their procedure and yours.

Thanks!

[shannon2014]

Ok I watched videos. Will follow those. What am I using distillers water for? I have cheap OTO KIT and will test shortly

[PoolDoc]

Run the OTO test, and I'll explain.

[shannon2014]

ran OTO test - water turned bright orange yellow.

[PoolDoc]

OK. Orange means TC > 25 or so.

I just wanted to double check your figures. Do this:

1. Collect some pool water, and mix exactly 1/2 cup of pool water and 1/2 cup of distilled. Test the chlorine level of THAT mixture using the 10 ml sample (0.5 ppm per drop of FAS solution). Multiple the result x2. That's your FC reading. Then, test your pH with the mixture. Take that reading directly, as your pH.

You can't test pH using phenol red when the TC gets above 15 pm. But you can dilute by 50% with *distilled* water, without changing the pH. However, the TC will be lowered by 50%, the phenol red can function as expected.

2. Tell us what FC and your pH readings are, and what you pool water looks like AND what the algae spots look like.