Algae?

[captainstabbins]

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 Water is clear

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 rto help me.

Thanks

[lisaa]

You should take care of your water first, 6.1ph is really a critical problem, if its below 7.1 it will damage your pool.I recommend you to use carefully the tricolor, It can also affect ph level.

[captainstabbins]

I went from 7.9 to 6.1 over the course of 2 days. I am getting my water tested tomorrow. It has been raining like a bear for the last 2 days.

[czechmate]

Locate the Pool calculator on Internet.
It will tell you in detail what you need to do.
It will save you time waiting for a response here, as well as not always the correct advice.
You will always have it handy and in the course of one year you will learn the chemistry interaction on your own.