Algae??

I have been dealing with an issue for over a couple of years. It is a very intermittent problem. Last year I had what looked like a speck of dirt that ran and left a trail. I have a tree over the pool that drops seed pods and helicopters into the pool. Also there are birds that stay in the tree and leave bird crap on the deck. Last year I was told that my nitrates were high and drain half the pool and refill . I did that and the marks went away. This year they are back.

If I shock the pool the marks go away. In the morning after shocking they come back.

My readings are as follows: Pool 12,000 gunite

FC .03
TC: 1.7
CC: 1.4
PH: 6.1
Hardness: 241
Alk: 86
CYA:23
Copper: .04
Iron:0
Nitrate: 12

I use trichlor pucks. I am at wits end since I have shocked, scorched and brushed with a wire brush and the marks keep coming back. I did add PH stabilizer yesterday to bring the PH up.

Hopefully someone will have an idea to help me.

Thanks

i'm no expert but if you are using granular chlorine as shock you may want to switch to regular store bleach, or pool chlorine which is higher percentage than store. i was having same issue trying to rid of some brown looking dust that appeared to be mustard algae and used pounds and pounds of granular chlorine. did not work. used 4 gallons of 6% walmart clorox for my 16k gal ig pool one evening and by morning stuff had cleared. just anidea. there should be more experienced people posting their thaughts i'm sure.

your pH seems extremely low- not sure, but some stains and water balance is affected severely when pH is out of range. I'd recommend getting it up to maybe 7.2, continue maintaining other chem levels at good levels, and then see if the stain stays or goes away...

I added PH Stabilizer yesterday for the PH.

You need to take care of your water problem first and then let someone address your stain problem.

How recent are your readings? If they were taken before you added pH stabilizer (whatever that is), you need to retest. A pH of 6.1 is a critical problem. Anything below 7.0 is acidic and will damage your pool.

Triclor is very acidic and will drive your pH down. Check the ingredient label on your trichlor. Is copper listed as one of the ingredients? Some trichlor tabs have it and we do NOT recommend that you use it.

What product have you used to shock with? How high have your shocked? With your CC reading and low FC reading, you need to shock your pool up to about 12ppm and try and hold it there. I suggest you just use plain, unscented household bleach. Generic from Walmart is just fine. Each quart of 6% bleach will add about 1.2ppm of chlorine to your pool. Test a couple of times a day and each time, add enough bleach to bring it back up to 12. Also, run your pump 24/7 right now. You also need to get a good test kit so you don't have to rely on the pool store. We suggest the Taylor K-2006 or 2006C which is the same kit with larger quantities of some of the reagents.

I would also suggest you do some reading on our sister website poolsolutions.com as there is a lot of good information that will help you.

By the way, what type and size of pump do you have?

pH stabilizer I believe helps maintain your pH at its current level- its used with trichlor to keep your pH from dropping to quickly, but doesn't bring your pH up much if any... you need to add probably borax to increase the pH, since your hardness is already up.

Spots are gone for 1 week and water is balanced properly. So hopefully all is good now.

Great! Time to go swimming!

Awesome! and I agree with Watermom- its SWIMTIME!!! (not the product, just the time of day!)