Desperate for answers on Mustard Algae

[CUTURHAIR]

Thanks for all your help everyone! I hope to get through this at some point! I just wish I didn't have to leave town next week.

I would much prefer to just deal with it via chlorine. I know I need more CYA, but am doing it slowly as I am not sure at this point how much I have, and how much more I need to add to get into the 40ppm range. So, I keep adding by the half pound. I "believe" I have added 2 pounds so far.

So, say I stay the chlorine route for now, until I get back from vacation, and try to up my CYA more, and lower my PH, and keep shocking close to 15ppm as possible? Does that sound legit?

If so, what do I do first, add more CYA, any guess how much, being it has clouded my test water, so I know there is some there, just not up to the 30 mark yet.

Or, add muriatic acid to drop PH first? Can I do these two things by doing one today, and the other tomorrow?

I am using my PoolBuster Max CG vacuum, and not using my pool vacuum at all, so I don't have to worry about backwashing out my stabilizer, since there will be no need to backwash.

I haven't used the muriatic acid in at least a season or two. Can y'all tell me how much I need to add to drop from 7.9 to the preferred range in 11,200 gal vinyl pool? I think I just pour it from the measuring cup into the deep end?

Then, if I recall, that can/will alter Alkalinity?? How soon can I address that issue?

If y'all can give me the best order I should add these chemicals, and how long I need to wait in between, that would be great!

Thanks for your patience. And Dave, you are right! I have gotten slack on my numbers since last season, and hence, PROBLEMS.....

John

[duraleigh]

Hi, John,

It sounds like you don't have the bleachcalc....download it from any of mwsmith2's posts.....it'll calc Chlorine, pH, CYA and make it easy for you to put in accurate doses.

Next, I would bring down the pH. use the bleachcalc and aim for 7.4...you'll get pretty close if you measure accurately. pour it in front of the return jet...don't put it in the skimmer. (everything else can go in the skimmer)

Simultaneously with pH, I would add enough CYA to get to 30-40 range. The container will tell you how much to add.

If you get those in this afternoon, I suggest you bring Cl up to around 15 or so at dusk....it'll be most effective in the dark. If you can, test again before you go to bed and bring it right back up to 15. Tomorrow morning same thing. Repeat this daily (if you can test and add during the day as well, that's even better) until your Cl loses less than 2ppm overnight.

Adding polyquat to this regimen will hurt nothing and may very well be what you need to finish the job. Without the above steps, I'm not sure you'll have much luck.

I have no experience whatsoever with Sodium Bromide so I cannot comment.

I hear your frustration, John, but my money is on you ending up the winner....not mustard algae.

[CUTURHAIR]

Dave, thanks for all the help so far! I tried to download the bleach calculator, but it is not able to take me to the link. Any ideas what is going on with that? I am clicking on the link beside MWSmith's siggy.

Thanks,
John

[Sherra]

He's apparently changed the link trying to make it shorter...here's the original link and I just tried it so it should work. Save the file to your desktop so it's readily available...it's a VERY small file.
http://www.hal-pc.org/~mwsmith2/BleachCalc262.exe

[CUTURHAIR]

Thanks Sherra, but the link didn't work! It isn't meant for me to get this calculator today!!

John

[CUTURHAIR]

OK, here is where I am today. I added 2 cups of muriatic acid yesterday. PH started at 8.0 and was at 7.5 after a while. TA dropped to 80 from 90. I also added another 3/4 pound of stabilizer, so I will have to give that a while before testing. I added four 96 ounce jugs of 6% bleach last night to shock, which actually took FC to 16.5 ppm. I checked again this morning and FC was 16, so I only lost .5 ppm overnight, which is a first. Do you think that is partially due to dropping the PH, making the bleach more effective? However, my TA was up to 100ppm this morning. So it started at 90 yesterday BEFORE the mur. acid and dropped to 80 yesterday after the acid and was 100 this morning. The PH had also drifted a bit more as well, and was around 7.3 this morning. I believe PH readings are not that accurate with shock levels??

Also, there was much less algae in the pool this morning than normal. I vacuumed yesterday morning, and brushed the pool down in the evening. I rebrushed the entire pool again this morning and will check chlorine levels again in a few more hours.

I feel like my CYA is soon to be near the 30+ mark. I know it is >0, but ,<30, as I can see the water is cloudier than plain pool water when it is in the tester, so I think that will be in line soon.

Dave, you recommend adding Polyquat, so can you tell me how much I should add for 11,200 gallon vinyl pool? And, do I need to continually add polyquat after this initial dose for maintenance sake, or just one time? I really want to take all measures to get this under control before I leave on Saturday for the week. My friend will be able to vac. and brush and add bleach, but I really don't want him messing with any other chems while I am away. No telling what I could come home to though.

Anyway, let me know what you think so far.

Thanks for all the help from everyone, btw!

John

[duraleigh]

Good morning, John,

I have never used polyquat so I have nothing to offer other than I'll bet the dosage is on the bottle. Others may know.

John, I personally have never needed polyquat but Pooldoc indicates it does no harm, is probably a very good preventative, and may be helpful as a cure.

I like your pH and Alk numbers. Don't overworry if they drift around somewhat.....that's maybe as much due to the testing vagaries as anything else. Just keep them around where they are.

You are wise to restrict your neighbor to bleach. You are doing everything well (very accurate additions of your chemicals) and I believe you will see continuing improvement in your pool if you continue the regimen.

I'm not sure the lower pH helped the Cl....I've read that but don't know. The results are what matters and I got a feeling you are gonna' get good results