Wow. Really? My stains are definitely brownish, and my copper test kit shows high amounts of copper, both at the pool store and from my own testing. However, I haven't tested for iron, and you're right, the ascorbic acid did seem to struggle getting rid of all the stains. Looks like I probably have both iron and copper. My problem is that I cannot even do an accurate CH test because the metal taints the color of the samples, even when I follow the instructions on the Taylor manual by prepping it with five drops of titrant. It still doesn't show an accurate color due to the high metal.
I really appreciate the EDTA Based reocmmendation.
I just opened the pool two days ago, and the water is still cold, but here is what my numbers look like thus far.
CYA: 120 (my achilles heel these last two years - it was 200 last year!) That's why I switched to BBB.
FC: 7.5 (started out at .5, but it's holding steady for 24 hours at 7.5)
CC: 0
PH: 7.2 (Started out real low at 6.8, probably due to pool store used pucks to winterize) It's rising slowly but steadily.
TA: 70
CH: 200-300 (Very hard to tell because of the copper interfering with the test)
Temp: 69F (Using the heater just a little each day until I put on my new solar cover)
Should I have a TDS, Iron and Salt tester in my arsenel of test kits?
waterbear said:
What color are your stains. Copper often does not respong to ascorbic acid but iron does. Were the stains yellow, orange, or brownish? Those are iron. In fiberglass pools copper stains are usually grey to bluish black.
You are right that Metal Free is not that effective, it is EDTA based, You want a sequesterant that is HEDP based (looik for DEDP, Phosphonic acid derivative, or phosphonates on the label). Jacks Magic, Proteam Metal Magic, GLB Sequa Sol are a few good ones.
Also keeping your CH levels up can help prevent staining, at least from my experiences with my own pool and my customers.
Posting a full set of test results would be helpful.