Want to get the chemicals right ...

[PoolDoc]

Do NOT raise the pH; your TA needs to drop, and you'll also tend to restain. Hold the pH at 7.0 - 7.2 until your TA is around 100.

Consider buying some CuLater units:
The CuLator product is a special patented plastic material, contained in a bag that goes into the skimmer, that can slowly take metals OUT of your pool water. We think it works, and have some evidence that it does, but not proof yet. (Not likely to be available locally.)

1 ppm Culator @ Amazon
1.5 ppm Culator sold by Amazon, shipped from Periodic
4 ppm Culator sold by Amazon, shipped from Periodic
Poolmaster 16242 Poolmaster Skimmer Basket Liner @ Amazon (to protect CuLator from being damaged by scum)

Remember, any metal lifted by the Metal Out is STILL in the pool water. Since you have a sand filter, you can remove metals by chlorinating with cal hypo in a somewhat tricky way -- but the CuLator units are much less tricky and seem to work.

Dichlor is a VERY easy way to chlorinate in your situation -- it adds chlorine (good), adds CYA (good for now) and tends to lower the pH (also, good for now!) The trick is getting dichlor that hasn't been diluted with goop that useless or worse (and I mean that literally, not figuratively!). If you have access, Sams Club is the cheapest source, but the Kem-Tek at Amazon is not bad:

24 lbs PoolBrand bagged shock @ Sams Club
Kem-Tek Dichlor 22 lbs @ Amazon

[Debits26]

The pool has been looking pretty good for the last few days. Here's my primary question at this point:

In my large pool, how much of the different chlorine sources will add 1ppm to the overall pool?
Dichlor
Bleach
Trichlor pucks

Once I have those numbers stuck in my head, I'll be able to maintain the right FC levels. Last night we were still at 11ppm. I'll test again when I get home in about an hour.

This weekend, I will be adding another quart of metal out to the pool and getting in with a sock filled with ascorbic acid to wipe the iron stain off the fiberglass walls. Wish me luck!!

[PoolDoc]

• Dichlor (from the sources I recommended) is 55% avail Cl2
• Trichlor (from Sams Club) is 90% available Cl2
• 6% bleach is approximately 0.5 lbs Cl2 per gallon
• Your PF is 2.7

So

1 lb dichlor => 0.55 x 2.7 = ~1.5ppm
1 lb trichlor => 0.90 x 2.7 = ~2.4 ppm
1 gal 6% bleach => 0.5 x 2.7 = ~1.4 ppm

[Debits26]

PoolDoc,
Thanks for all your help earlier this month! My pool has been looking good. I did the ascorbic acid treatment last weekend and most of the stains are gone. Thank you all for that great trick! My pool has really never looked better. The only problem is that while the acid was working, I had the filter on Recirculate, and lost about 5 inches of water depth. I had to add a lot of water the next day (adding some more metal into the mix).

Since then, I've been adding about 1 lb. of dichlor a day over the last week and now the water is white cloudy. We are unable to see the main drain through the water and I fear I'm on the verge of an algae bloom. After the acid treatment, I put 64 oz. sequestrant, and the filter has been running 24/7.
Here are my numbers today:
FC: 0
TC: .5
pH: 7.4
TA: 125
CH: 300
CYA: 35
Obviously, I need to get the chlorine levels up. I have added 5 bags of dichlor this week, and I added 85 oz. of polyquat. I'm planning to bring the chlorine up to shock level tonight (15ppm). If there's anything else I should do, or if any of this sounds off, please let me know.

Thanks again for all your help.

[Watermom]

When you shock the pool, you may get staining again. Whenever you have metal-contaminated water, it is critical that you never let your chlorine level get lower than the minimum advised in the Best Guess Chlorine Chart. That way, you won't have to shock for an impending algae bloom. Otherwise, you just have a repeating cycle. If you have algae, you have to get the chlorine level up enough to kill it and then, if you have staining, you'll have to do another ascorbic acid treatment.

[PoolDoc]

The only problem is that while the acid was working, I had the filter on Recirculate, and lost about 5 inches of water depth. I had to add a lot of water the next day (adding some more metal into the mix).

You may need to look into repairing or replacing your multiport -- you shouldn't have lost any more water than normal, while on recirculate.

Follow Watermom's caution - it's best if you can avoid having to shock a pool with metal problems. You can add dichlor or bleach via the skimmer, which will tend to drop out metals onto the filter.

Also, you need to keep HEDP on hand, and add a small (maybe 1/8 normal) dose TOGETHER with the fill water, when ever you add water. If you have a CuLator bag, it would be good if you can put it back in, for at least a couple of days after each water addition.