So I just recently learned a very valuable lesson that is saving me a ton of time, aggravation, and most importantly money
I have been dealing with a very rough metal issue for over 2 years. I was buying sequestering chems by the boatload. To the tune of $40/week. And sometimes that wasnt even enough.
In an unrelated event, I had a cloudy water issue that wouldn't clear up. I backwashed the DE filter.
Replaced DE. A few hours later, there was DE all over the pool floor. A lot of it. I quickly realized that I might as well have been leaving the filter off for all the good its been doing. And it was probably functioning horribly for 2-3 years.
Replaced the grids. Charged it. 2 days later, pool is perfect. Weeks later, no sign of any metal staining at all. Not the slightest bit. This is by far the longest in years I have been able to go without adding sequestering agent.
The lesson learned to me was that excellent filtration is the best sequestering agent!
If someone is dealing with metals that just won't be removed from the pool, my suggestion is to check the filter. Clean it well. Make sure there are no rips in the grids or casing. It seems to make a world of difference.