New user with algae

Hi, I am a new user to this site. I wish I would have found it 30 days ago. I am struggling to get my pool in good working order this season. Algae is the biggest issue. However, I did replace the pump motor, DE Filter grids, and last weekend had to replace the booster pump seals. Everything is functioning correctly now, but I can't get ahead of the algae. Finally one of the guys at the local pool store told me my stabilizer level was too high. He didn't tell me how high it was but that it was too high. He instructed me to put 8 lbs of shock in on Friday, backwash and brush again Saturday and drop 4 more lbs of shock. Most of the green is gone, but there are still two areas on the bottom of my pool that are mustard color and three areas that appear to be dark brown or god forbid black algae. Yesterday I drained approximately 1/3 of the pool and am refilling now in an attempt to lower the stabilizer levels. Once the pool is full again I will retest and get a more accurate level. On my way to Walmart to buy bleach and an HTH 6 way test kit. Any recommendations are greatly appreciated.

What are the ingredients in the shock? You say you have high CYA. If the shock is dichlor, then you are adding more and more CYA with each bag of shock.

A 6-Way kit can help you get started (make sure you do NOT get the HTH 6-way test strips!) but, if you do have high CYA, that kit is not going to be able to measure the high chlorine levels you are going to have to run. Take a look at the Best Guess Chlorine Chart at this link: http://pool9.net/cl-cya/. It explains the connection between CYA and needed chlorine levels.

The kit that CAN measure high chlorine levels is a Taylor K2006 or 2006C (better buy). Can't buy it locally, but can buy it through this link. http://pool9.net/tk/

Don't add any more products to your pool other than bleach until you get a CYA and pH reading. Sometimes adding more stuff causes more problems.

Hope this helps! Welcome to the Pool Forum!

(By the way, until your registration is completed, you'll have to log out first to be able to see the rest of the forum. So, copy the links and paste them into a browser window after you log out.)

Your response is very much appreciated. I am using Dichlor and did not realize it also included stabilizer. I thought just the Trichlor tablets added stabilizer. Good information to know. I bought the HTH 6-Way test but it didn't include strips. Even after a 1/3 water drain and refill, my CYA levels are over 150. The PH level is 6.8 total Alkalinity is 80.

Most critical right now is bringing your pH up. Since 6.8 is the lowest reading on your tester, it means that it could actually be much lower than that! Readings below 7.0 are acidic and can damage your pool. Go to Walmart and buy several boxes of 20 Mule Team Borax (laundry aisle.) That is what we recommend for raising pH. You didn't list the volume of the pool, so I can't comment on dosage.

Since you already have the 6-Way kit, if you go to the same test kit link I posted above, you can just buy the FAS-DPD test (Taylor 1515) kit. This will give you the chlorine test that will allow you to measure the high chlorine levels you are going to need due to your high CYA.

. . . membership upgraded.

Read the cl-cya page; the correct chlorine level is determined by the CYA level:

http://pool9.net/cl-cya/

With algae, you'll need 20+ ppm. Right now that translates to dark yellow with an orange tint -- to orange on your OTO test kit.

Also, you can NOT operate a DE filter with live algae in the water; it will stop up the filter almost instantly. Kill the algae, first. With very high CYA, you'll need a starting dose of 5 gallons of PLAIN 8% household bleach for each 10,000 gallons in your pool. Repeat those doses till your chlorine mostly survives overnight.

DO NOT try to test with strips or with a DPD color match; neither will give accurate readings with those chlorine levels. OTO is not too accurate, but the results will still be meaningful.