Mustard Algae??

I have spent all day reading the forums trying to soak up as much pool knowledge as I can. I decided to join to ask about my current problem. Came home last night from a long weekend and the pool did not look good. I have been doing the BBB method for two seasons now, although I get lazy and cheat (powdered shock and algeacide) from time to time (I know, i know... look where it has gotten me.)

Anyways, I am not sure if my problem is mustard algae, green algae or pollen/dirt. The pool water was, slightly cloudy but had streaks of brownish/greenish/yellowish debris on the walls and bottom (I have a fiberglass pool). It brushes easily but then clouds the water and gives a green tint to the water.

I tested this morning after adding bleach, here is what I got:

FC: 10
CC: 0
pH: 7.6
T/A: 90
CH: 100
CYA: 50

Went to the store bought more bleach and started adding, trying to get up to 30 as per Ben's Best Guess chart, going on the assumption that it is mustard algae. Raised it to 30 and retested about 3 hours later was at 25, added more bleach to bring it back up.

That is where I am at now. So my questions to the pool experts: How can I tell which problem I am having? Do I want to brush the bottom and sides and leave pump on to filter it out; should I vacuum and backwash or should I vacuum to waste? How long do I keep FC at 30?

Thanks so much for your help!
Holly

Hi Holly,
If all the debris is on the floor and you can vacuum it without stirring it up,. go ahead and do so. If not, then brush and get it into suspension where the filter can catch it. What kind of filter do you have?

Bring your water back up to shock level this evening. An hour after adding bleach test the chlorine. Then in the morning within 2 hours of sunrise, test your chlorine again. If you have lost no more than 1ppm of chlorine overnight and still show no CC reading, then it is not algae and is most likely pollen, etc and you can let your cl drift down. If you do lose more than 1ppm, shock it again a couple times per day and continue this until you can pass the overnight test.

Yes, brush and vacuum. You want to knock it loose so the chlorine can kill it and the filter can filter it out.

Welcome!

Carl

Thanks for your responses!

So last night we had a big thunderstorm come through so couldn't do a lot with the pool. However right before bed (while it was still raining, I am dedicated!) I retested and it was back down to 25, so I added another bottle of bleach, quickly! Did not have high hopes for this morning.

I was so happy to wake up to a blue pool, however it is milky/cloudy, but blue!! Retested and FC was down to 15 with no CC. Just added more bleach and brought it up to 26. I brushed the bottom and got very little dirt/algae/whatever but because of the storm not sure if this is new or old.

At this point, what do you think? I have a sand filter, pressure only went up 1 or 2 psi overnight. Not much to vacuum. I have some BioGuard Sparkle Up left from the old days of going to the pool store (had a metals problem, that I ended up fixing on my own without their help). Should I add the Sparkle Up to help the filter catch more of the particles? What should I keep FC at now that it is blue? Do I let it start to come back down or keep it up for a little longer?

Thanks again!!

Doing GREAT! That's exactly what should happen! Do NOT add the sparkle. You CAN add some Polyquat algaecide, maybe an ounce or two, not more.
Polyquat is sold under all kinds of labels, but the ingredients should be: 60% poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride] as the ONLY and SOLE active ingredient. It's the ONLY additive I ever use, and certainly the ONLY algaecide. It also doubles as a clarifier.

You can also put a little DE in your filter via the skimmer...Just enough to raise PSI 1 lb, but backwash first.
Also, skimmer socks in your skimmer can pull an AMAZING amount of junk out. I usually can make one last a month, and 3 or 4 go for less than $10.

Carl

Don't know about the Sparkle. I wouldn't use it.

But, the fact that you had such a big loss of cl overnight says that you need to continue shocking. Continue to do so until you can pass the overnight test.