Mustard algae

Hi - I'm new to the PoolForums. I'd like to be given full access so I can post a follow-up to this thread:
http://www.poolforum.com/pf2/showthr...-won-t-go-away

Thanks,
Josh

Not clear on how you are going to post a follow-up, on somebody else's pool.

I have a pool that's exactly the same size with exactly the same problem.

OK, but it would be better if we have a thread about YOUR pool. It tends to get impossibly confusing if we try to help 2 people with 2 different pools in 1 thread. Right now, with the forum so busy, the PF Support Team and I tend to get confused about which pool we're working on, as it is. I've personally made some really stupid posts as a result.

So, if you would, please tell us about YOUR pool, here:

Pool Chart Entry Form
Pool Chart Results

and then give us the details about your mustard algae.

Best wishes,

Sure! I filled out the form with details about the pool (23,100 gallons, 16'w x 35'l).

I have mustard algae (not pollen, it's clinging to the sides tenaciously). Algaecide isn't doing it, so I'm trying to super-shock it. So far I have the FC up to 12 PPM (pH is 7.2, alkalinity is 80, hardness is 250, and unfortunately CYA is 50).

Is this calculator correct that with a CYA of 50 and a water temp of 66 degrees, I need to get the Free Chlorine up to 29 PPM to kill the mustard algae?

And after I do that, should I lower the CYA levels (if so, to what) so that I can bring the FC down to a level that's safe to swim? Just looking some advice once I kill it off on the fastest way to get back to swimming safely while still keeping the mustard algae out. I read this thread (http://www.poolforum.com/pf2/showthr...-get-rid-of-it) but not sure how to make that apply to my pool.

A CYA of 50 is not high; in fact it is the level that we recommend for most pools. So, even once you have this cleared up, you don't want to lower it. With a CYA of 50, the maintenance levels for chlorine are between 3-6ppm and are not too high to swim in.

For now, take the chlorine up to 15ppm and try and hold it there as consistently as you can. If after several days of being consistent you find that it isn't working, then we may suggest going higher. With a vinyl liner, you don't want to go higher than needed for fear of bleaching out the liner.

Don't add any more algaecides. They are a better preventative than they are at killing algae and some of them cause additional problems like foamy water.

I also wouldn't advise using any more trichlor tabs. They are stabilized and will continue to add CYA. Just stick with bleach for now.

Do it like this:

1. Add bleach in the evening, pouring into the pools along the sides where the algae is.
2. Brush the algae right away, and again, in the AM.

Thanks for filling out the form.

Membership upgraded.