Drained and refilled- now?

[Guest]

Due to some ugly staining (that apparently was from iron), we drained, acid washed, and refilled.
Before draining, the iron measured at .15
Copper measured at .5, and I think I have some copper staining on the plaster (beautiful blue color) that was not removed with the acid. It seems rough, and it seems to be on top of the plaster.
So:
Question 1 is : how do I remove the copper stain?
Question 2 is: should I use something regularly to prevent any more staining?
The current readings are:
FC .5 (in the process of shocking)
CYA 20 (added in 30 oz liquid and have not retested)
TA 140 (I lowered the ph a bit since this reading)
PH 7.5
copper 0
Iron 0
TDS 700
So - now what?

 

[PoolGuyNJ]

The blue as you suggest is likely copper but I doubt that caused the roughness. That, I fear, is etching and is usually indicative of either an old and worn finish or a combination of a low pH and low calcium condition having existed over a period of time. I also suspect that the copper stains are deeper in the finish than you thought and that they came from a pool heater's heat exchanger being etched from the low pH water running through it.

Without pictures, we can't say for sure but sounds to me like you may need to refinish the pool. What is the current finish on the pool?

It is also possible that a light sanding with a 220 grit wet/dry sand paper may be of some benefit of the etching isn't too deep and the finish type is not a high aggregate type. Again though, with out pictures and us knowing the finish type, we can't say for certain.

Scott

 

[Guest]

I don't have a heater, so that is not an issue.
If anything, the PH was always on the higher side, not low.
This is a 9 year old plaster pool. I will see if I can post some pics

 

[Guest]

I have tried to attach pics and keep getting a message that file is invalid -
Here are the latest readings. I went to 2 places, and got 2 different readings. How is it possible to be so different?
Please advise --

Place 1: Place 2:
FC 5 FC 3
CYA 20 CYA 0
TA 100 TA 120
PH 7.4 PH 7.4
Phos. 1000 Phos. 600
CH (not tested, CH tested at 200
but guy said it comes
out of tap at 250)
First reading is from Leslie's, the 2nd from my local place that tests all by hand with Taylor test kits.
Both said to treat phosphates, although 2nd place said to really just watch it. (I know pool school says don't worry)

 

[duraleigh]

(I know pool school says don't worry)

You can take that part to the bank! :-D

Actually, those two are not that far apart.....often it is much worse.....that's why doing your own testing and trusting it is so essential to what we teach.

Your first post said you were shocking but your test results indicate you are not. What does your water look like?

Ridding yourself of the copper stains is going to be incredibly difficult and I am of no help.

Preventing any more stains is relatively easy from here on out......control your pH, don't put ANY copper in your water, EVER., control your source water (that's probably where the iron came from. The copper I'm not sure...it may have come from copper laden algaecides.

 

[Guest]

Does it make sense that the shock probably did nothing because the CYA was nothing?
The water looks beautiful right now! I added more stabilizer and will add liquid chlorine tonight.
I'm concerned about how to add the chlorine though, because I don't really know what my cya is. Started at 0, added a gallon of liquid this morning, so how do I know how much chlorine if I don't have a true cya reading?
I am overwhelmed with the pool school info, but I keep reading and rereading, and it is starting to sink in.
I know (now that I'm educated), that the copper came from algaecide that I used, and that if I stay on top of my chlorine I will not have to use that ever again. Pool guys tell me that iron is rare in our water, but somehow it got there. That I'm not really sure about. I will only use liquid chlorine now, and will stay on top of my testing.

 

[Guest]

How much chlorine

MOD EDIT: Moved to your original post, please keep posts in one thread for continuity. Thanks, linen

Starting a new post for this question - thought maybe it would get lost on my old post.
Since my pool is newly filled, and I have just added CYA (today) so don't have a true reading on it yet, how do I calculate chlorine?
What CYA nbrs do I use if I don't really have a good number for that yet?
And, do I need to worry about shocking if my pool is newly cleaned and filled? Water looks really great!

 

[woodyp]

Re: How much chlorine

See the CYA/chlorine chart in pool school and aim for the target number that matches the level of CYA you added.

 

[Guest]

Re: How much chlorine

okay, so the bottle said it would increase by 30 ppm (using the bottle) on a 10k gallon pool. I will use that as an estimate to start. I will go purchase a test kit and do the overnight test to see if I need to shock - tnanks for the help, and thanks to pool school!

 

[linen]

gemphx, please put your pool details in your signature.

okay, so the bottle said it would increase by 30 ppm (using the bottle) on a 10k gallon pool

What is your pool volume and how much cya did you add? Is it liquid or granular?

I will go purchase a test kit

Make sure the test kit you buy has a FAS-DPD chlorine test. See my link in my sig on test kits.

 

[Guest]

The CYA is liquid, and I added one gallon. I know I will need more, but is it safer to go slowly so I don't overdo it? I thought I would wait a few days and then test it to see how much more I will need. Thoughts?

 

[linen]

The CYA is liquid, and I added one gallon. I know I will need more, but is it safer to go slowly so I don't overdo it? I thought I would wait a few days and then test it to see how much more I will need. Thoughts?

Sounds right then, using poolcalculator I get 32 ppm cya (starting at 0), for 11700 gallons using 128 ounces of liquid stabalizer.

If you are going to do the shocking process, it is better to do that at a low cya level (like what you have) then raise the cya up after totally finishing the shocking process.

Let us know what you get from the OCLT.