yellow algae

[ronjorob]

having trouble yellow alg .wiil just using high does liq chorine kill it . allchemicals are in range

[Watermom]

You'll need to give us more information for us to be able to help. Please fill out our pool chart with your information. Also, give us a current set of water testing results taken with a drops-based kit. (Saying that chemicals are in range doesn't give us enough to go on.) Then, somebody here will try and assist you.


Pool Chart Entry Form (http://goo.gl/cNPUO)
Pool Chart Results (http://goo.gl/PXaLu)

Welcome to the Pool Forum!

[ronjorob]

clor.9 ph75.cya60. alk90

[Watermom]

Thank you for filling in the Pool Chart for us. Are the tabs you are using trichlor? If so, I'd suggest that you stop using them and just stick with the liquid chlorine. The tabs are stabilized and will cause your CYA to continue to rise and yours is already high enough.

With a CYA of 60, you need to keep your chlorine level between 5-10 all the time and your shock level will be 20. (Take a minute and read the Best Guess Chlorine Chart in my signature above.) So, I'd suggest shocking your pool and try and keep it at shock level until you can go from sundown one evening until within two hours or sunrise the next day without losing more than 1ppm of chlorine and your CC reading is no higher than 0.5ppm and your water looks clear. Then, keep the chlorine high one extra day for added insurance and then you can let the chlorine drift back down but don't let it go lower than 5ppm.

For reference and to help you figure out doses of bleach to use, in your pool, each gallon (4 quarts) will add about 2.7ppm of chlorine. (Is that what you are using when you say liquid chlorine? If you are using liquid pool store chlorine, what concentration is it?)

Your pH and alk are fine.

Hope this helps.

[ronjorob]

i have 3 tabs tricor in pool now.do i shock with liq or super shock powder. i use 10% concenrtate chlorine. isnt the powder shock tricor & will raise cya. thanksu.

[Watermom]

The shock powder might be dichlor or it might be cal-hypo. Look at the label and tell us what the ingredients are. After the trichlor tabs that are currently in the pool dissolve, don't put any more in. You don't want your CYA to get too high. If you are using 10% sodium hypochlorite, then each gallon (4 quarts) will add about 4.5ppm of chlorine.

[ronjorob]

powder is tricor. so i wont use it. so if chlor level is 7 &i add 2 gallons liq it brings it up to shock value of 16?

[Watermom]

Not quite. Shock level for a pool with a CYA reading of 60 is 20ppm. If you add the third gallon it would bring it up to shock level.

[ronjorob]

added 3 gal chor then added another 24 hrs. later . still got algae. now not sure if it is algae or stain. i goofed in my chart i have a ig pool with gunite pebble tec.

[aylad]

You need to hold that shock level until the algae is gone, testing and adding more bleach as needed. Letting your chlorine yo-yo up and down like that won't ever let you get ahead of the algae and kill it.

Janet

[Watermom]

There is a thread in the notes and announcements section where you can give the corrections that need to be made to your Pool Chart Entry.

[PoolDoc]

If you'll look at the Best Guess page linked in our signatures, it will explain why, and give you the chlorine levels that you need to eradicate mustard algae. In your case, it will probably take 25 - 30 ppm sustained over a week or so, plus brushing. You'll have to get a K-2006 test kit (see test kit info page) to measure and control those levels.

There are other ways to do it, but they have other complications, too.

[ronjorob]

bleach is 6% concentrate and chlorine at orcharde supply is 10% and cost is not much higher

[Watermom]

If it is 10% sodium hypochlorite and a better price and fresh, they buy it. One thing I will tell you is that higher concentrated sodium hypo sometimes isn't the percentage it is advertised at especially if it isn't fresh. Here's a way to test the concentration of your bleach...I copied this from CarlD, one of the other mods, that had posted it a long time ago...

Put ten liters of tap water ( That's 5 soda-bottles full) in a 5 gallon bucket.

Test that water for chlorine using the FAS-DPD test to get a chlorine baseline (you may have some).

Then I take a 1 ml eyedropper full of the LC or bleach I'm testing and put it in the bucket and mix it up.

(1 ml in 10 liters of water is the same as putting 1 gallon of LC in a 10,000 gallon pool -- it's 1/10,000th. )

I then measure the bucket with the FAS-DPD test just like pool water. Of course, subtract any chlorine you measured in the tap water.

I use a glass eyedropper so it will hold up. Pharmacies sell them.

[ronjorob]

been shocking pool like u recomended & still have alge or stain.water is crystal clear. been adding 3gal of 10% chlorine everynite. have a reading of over 23 ppm. next morn reads 20ppm. combined chlor is o. all my other chemicals r right on. lose about 10ppm chlor thoughout the day.

[aylad]

If you're still losing 3 ppm of chlorine overnight, then you're still fighting something in the water and need to maintain the shock level.

Janet

[PoolDoc]

still have alge or stain.water is crystal clearhave a reading of over 23 ppm. next morn reads 20ppm.


In your case, it will probably take 25 - 30 ppm sustained over a week or so, plus brushing.