Need help with pool chemistry

I have a 15'x30' above ground pool.
Pump running 6hr/day
Sand filter
SWCG 6hr/day

New pool, been running for about 2 weeks without any problems.

Water is starting to look a little yellowish/greenish and has a little bit of a slime feeling on the bottom.

Using test strips this morning:
FC: 0.5ppm
pH: 6.2
TA: 40
Copper: 0.1ppm

I currently have my pump/filter on with the SWCG running a "boost" cycle to bring up the chlorine. I'm not sure what I need to do about the cooper, TA, & pH.....

When I opened the pool I added 250lbs of salt and 2.5lbs of Cya____ Acid (whatever that stuff is called, lol)
I dont yet have test strips for the salt level but the SWCG has not alerted a high/low salt level
Nothing else has been added since.


Thank you all!

We don't trust test strips. The kit we recommend that everyone get is the Taylor K-2006 or 2006C (test kit link in my signature below.) It has to be ordered online as it won't be available locally. You can also order test strips for the salt test at the same time. (For that test, it is ok to use strips.)

In the meantime, go to Walmart and pick up a cheap OTO/Phenol Red kit (yellow and red drops). Test and post readings.

While you are at Walmart, pick up several boxes of 20 Mule Team Borax (laundry aisle), a jug of distilled water, and several jugs of plain, unscented bleach (generic is fine). You also should get a few boxes of baking soda.

I would also suggest turning off your SWCG for now. SWCGs are fine for chlorine maintenance but whenever you are dealing with algae, it is best to supplement with bleach to save on the cell life.

Go ahead and read the Best Guess Chlorine Chart in my signature below. It explains the relationship between CYA and needed chlorine levels. Adding 2.5lbs. of CYA would take you up to around 80ppm. Since you are seeing the signs of an impending algae bloom, you need to shock your pool up to about 20ppm. In your pool, which I am guessing to be around 3600 gallons, each quart of 8.25% bleach will add about 5.7ppm of chlorine. Use that as a reference to help you figure out doses of bleach to add to get to 20ppm.

You will want to test your pH with the OTO/Phenol Red kit before you add the large quantities of bleach because high chlorine makes the pH test inaccurate. So, test pH first. If you are below 7.2, add some Borax slowly to the skimmer, breaking up any clumps. I'd start with about a cup. Wait a couple hours and retest pH, and redose if needed until your pH is between 7.2-7.8. Then, add the bleach.

By the way, I assume your pool dimensions are 15' x 30" instead of 15' x 30.'

Hope this helps.

Thank you Watermom

A couple things;
1. I cant go to the "Get the test kits you need" post. I get a message that says "you do not have permission to access this page"
2. My pool is a 15'x30' oval. approx 4' deep throughout so my water capacity is closer to 12,000 gallons.
3. After making the original post I found I had a large bag of baking soda. I added 9lbs per it's suggestions to bring up the TA.

Should I still ad Borax? or just wait a bit and test the pH and add Borax as needed if the pH is still low?
So bleach = shock?
Is this better then using actual shock?

Should I add more CYA to increase the TA more?


Thank you for your help!

Water test after the baking soda (still just using the test strips):
Hardness: 100ppm
FC: 0.5ppm
pH: 7.6
TA: 120ppm
Stabilizer: 0

To get to the Testkit link, try this. Log out and go to the forum. Find most any post written by PoolDoc or me and click on the link from our signature there. (The problem is that until your membership is upgraded, then you can't see the rest of the forum.)

Get an OTO/Phenol red kit asap and test that pH. Like I said above, we don't trust test strips. If your pH really is that low, that is a critical problem! Any pH reading below 7.0 is acidic and can damage your pool and equipment. Test the pH with this kit ASAP and if it is indeed below 7.2, get some Borax in there!

CYA does not increase TA. Baking soda increases TA.

Your volume should actually be closer to 10,000. (Sorry about my mistake above.) So, if you added 2.5 lbs. of CYA, then your CYA should be around 35ppm. Find your manual for your SWCG. Most manufacturers have recommended CYA levels specified in the manual. It will definitely be higher than 35ppm.

Shocking is a verb, not a noun. Shocking simply means raising your chlorine level up to a high enough level to sanitize the water. Although some places still sell bleach that is 6% sodium hypochlorite, most places are now selling 8.25%. Pool store liquid chlorine is the same stuff --- sodium hypochlorite but just at a higher concentration like 10 or 12%.

Hope this helps. Let us know if you have further questions.