Beginning of an algae problem...

Hi. Over the past week or two I've been noticing a gradually increasing amount of algae in my pool, mostly in corners, on ladders, and along the bottom of walls. It's not bad at the moment, but it's been getting worse. I sweep it down every day, but it always comes back the next morning. Hoping someone could give me some tips!

Here's my test results for today as per my Taylor kit:

FC: 5.5ppm
CC: 0
PH: 7.2*
TA: 80
CYA: 50-60

I'm colorblind and have trouble reading the PH color chart, so that reading is what an acquaintance said it looks like. Looks the same to me but I don't trust my eyes, and my digital reader has not arrived yet.

Also, the pool was shocked up to 15ppm with cal hypo on July 23rd, about a week ago. Usually I use dichlor on the pool ('ChlorBrite' is the brand). I vacuum most days with a Pool Blaster, and usually once a week with the standard pool vac. Still my algae returns!

I try to run the pump at least 8 hours a day, although to be honest sometimes it can be as little as six. It's a Hayward Perflex with a 3/4 hp single speed superpump. Pool is 40x20 40k gallons with a vinyl liner.

Thanks!

Increase your fc to the +shock+ level for your cya on the Best Guess chart found here. Then HOLD that level until 1) water/pool is visibly clear of algae, 2) your cc is less than .5, and 3) you lose no more than 1 ppm fc from dusk to dawn. Then HOLD that level for one more day. Also, you should be running your filter 24/7 until the problem is resolved.

Also, use bleach instead of cal hypo or dichlor*, and continue brushing/vacuuming daily. *dichlor will increase cya and cal hypo will increase calcium hardness. And unless what you have is unblended dichlor, you shouldn't be using it at all.

Thanks for you're response. I used the cal hypo shock because my calcium levels tested extremely low and it was a convenient way to lower the amount of 'stuff' I'd have to load into my car (for my pool, shocking with bleach would take many gallons of bleach, versus a few small bags of cal hypo), plus it was on sale which made the price right.

What do you mean by 'unblended' dichlor? CYA has not been a big problem in my pool, if anything it tends to be a bit on the low side until mid-summer. Currently it is between 50-60ppm.

When we shocked it did clear up temporarily, so I will give sustained shocking a shot.

edit: Hey, I'm looking at bleach options for the pool. I'm not sure if there are any types that are not good for use in a pool? This stuff at is only a few bucks at Home Depot, but is it alright to use in a pool? Thanks.

http://www.homedepot.com/p/HDX-121-o...specifications

Calcium is irrelevant for a vinyl pool (unless it gets too high which can perpetuate scaling).
Bleach is almost always the least expensive method of adding chlorine. Usually walmart or aldi are the cheapest sources of bleach, but sales elsewhere can be good too. Easy to compare prices... $/oz./%. So if wm bleach is $3.25 and home depot is $2.99 (and assuming walmart is 1 gal whereas home depot is only 121 oz), 3.25/128/0.0825 = 30.78 cents per ounce of sodium hypochlorite and 2.99/121/0.0825 = 29.95 cents per ounce of sodium hypochlorite. Home depot wins in this case AS LONG AS what home depot is selling is regular household bleach (no additives, scents, detergents, etc.).
Or another way to look at it... 1 gal of 8.25% bleach provides about 2 ppm fc for yor pool at $2.99. That's about $1.50 per ppm fc. 16 oz of 53% cal hypo provides about 1.6 ppm fc for your pool... So unless you are getting cal hypo less than $1.50 per 1# bag, it's more expensive. At $3 per lb, you are paying nearly 2x as much as the same fc in bleach. You have to decide how much more you are willing to pay for the convenience of 1 lb packages vs. 1 gallon jugs.
Unblended dichlor is 99% dichlor... No other additives or components. Usually only available at SAMs club or online. Nothing but pure dichlor is ever recommended here that I have seen. If your cya is in the 50-60 range you might not want to add more. There are reasons to run higher cya levels but usually 50-60 is where you want to hold... And right now you need to eliminate the algae rather than worry about increasing cya.

I've been going through a lot of Bleach recovering from an algae problem. I stocked up yesterday at Target, they carry the 8.25% in 121 oz jugs. They have a special going buy 3 get one free which brings the price down to $2.24/jug or 22.44 cents per ounce of sodium hypochlorite.