manganese

[SUNOFTHEBEACH]

I drained and acid washed my pool last month. I refilled the pool with municipal water. During the fill I saw yellow water come out of the hose. When full the water had a green tint to it.
The DE filter cleared up the water. here is what the filter looked like after a week of being run.

There were news reports that stated the there was Manganese in the city water. More Maryland residents will see brown water coming from taps, utility says - The Washington Post

What is the red color on the de filter? manganese? iron?
I still have some issues. My taylor CH test goes from blue to clear, not red.
I am having issues with keeping my PH down, it always rises to 8.

Is all of this related to the suspected Manganese?

 

[JoyfulNoise]

It's highly likely that it was/is iron. Municipal water supplies can have lots of iron in them and not ever report it because iron is not considered a water contaminant. Therefore the EPA has not established any reportable levels for it. The green tint would also suggest iron as it would color the water green (blue water + yellow iron = green). Also, iron will interfere with the CH test - try adding a few drops of the R-0012 titrant BEFORE you add any R-0010 or R-0011L, it will sequester the iron before it locks up the indicator dye.

Looks like your filter caught most of it as it was being slowly oxidized and precipitated by the high pH and chlorine. Have you noticed any stains on your plaster walls?

Your pH issues are likely related to your new fill water. What's the TA?

 

[SUNOFTHEBEACH]

I had a few stains on my walls shortly after the refill. I assumed it was iron leaching out of my flagstone coping dripping into the pool. I also had my plastic parts (returns) turn yellow. Those cleared up when I rubbed Vitimim C on them. The floor of my pool looks slightly dirty.

My TA is now down to 60. I've been adding a gallon of Muriatic acid a week for probably 5 weeks.

 

[JamesW]

Manganese is usually purple or black. That looks mostly like iron.

 

[JoyfulNoise]

Your high pH is likely from the acid washing. It tends to dissolve the surface layers of calcium carbonate and can expose fresh plaster components like calcium hydroxide and calcium silicates. Those are highly alkaline materials. So your pool surface is acting like fresh plaster would - there will be a constant emission of calcium hydroxide until the surface carbonation reforms.

You'll just have to deal with the acid demand until the plaster settles back down. Keep checking your filter frequently because you want to make sure you're getting rid of all that iron.