I did a Metal Magic sponge test late last season and it indicated that I treat my stains with the maximum dose of MM. (Here are the highlights of that battle: Sequestrant vs. CYA Bound Chlorine ).
The MM lifted nearly all my dark gray stains and I continued to treat with a maintenance dose of MM until I closed the pool and then did a maintenance treatment again when I opened the pool early last month. In time, (about a couple of months total) my Culator Ultra 4.0 even turned yellowish-brown, swelled, and then shrank back down and got all crunchy inside. Whaddaya know, Culator skeptics (perhaps chem geek notwithstanding), but that's what Culator says will happen when the contents of an "egg" fill up and become spent!
Now I'm left with lighter tan stains that do not respond to a MM sponge test. Trichlor pucks do nothing to them. Ascorbic acid tends to darken the remaining stains (adds a gray color). but citric acid lightens them a little. The only thing that has lightened them significantly (yet not completely) is the Copper and Scale Stuff in Jack's Stain Test. The ID kit O2 and Iron Stuff combinations do not enhance the stain removal action compared to Copper and Scale Stuff alone, so I guess I'm left with mostly copper stains, which isn't surprising, given that the previous home/pool owner left a nearly empty giant blue bucket of nasty blue-speckled trichlor pucks in the pool shed. A professional lab result says our spring water contains 4.4 ppm iron and 0.0185 ppm manganese but essentially no copper, so the "plus-enhanced" trichlor pucks are almost surely the source of the remaining stain problem.
I'm thinking about treating with citric acid or perhaps sulfamic acid to see if the stains will lift (leaning towards sulfamic acid, because the Jack's Copper and Scale treatment produced the best results).
Both citric and sufamic acid treatments appear to impose post-treatment challenges. Citric acid chews up chlorine like crazy during post-treatment re-balancing and sulfamic acids seems very likely to knock alkalinity and pH off the map! I guess either method might produce another big dust cloud in the water like the one that cost me the end of the swimming season last year so maybe I'll wait for the water temp to hit 65 F before I begin my next full-on stain assault (too cold for pleasant swimming but still barely warm enough for stain treatments). It's now a very pleasant 78F.
What to you experts here at TFP think? Citric or sulfamic?
Are the specialty formulations of Jack's sequestrants worth the extra money over just the plain ol' HEDP in MM?
Thanks a bunch for thoughts and advice!
The MM lifted nearly all my dark gray stains and I continued to treat with a maintenance dose of MM until I closed the pool and then did a maintenance treatment again when I opened the pool early last month. In time, (about a couple of months total) my Culator Ultra 4.0 even turned yellowish-brown, swelled, and then shrank back down and got all crunchy inside. Whaddaya know, Culator skeptics (perhaps chem geek notwithstanding), but that's what Culator says will happen when the contents of an "egg" fill up and become spent!
Now I'm left with lighter tan stains that do not respond to a MM sponge test. Trichlor pucks do nothing to them. Ascorbic acid tends to darken the remaining stains (adds a gray color). but citric acid lightens them a little. The only thing that has lightened them significantly (yet not completely) is the Copper and Scale Stuff in Jack's Stain Test. The ID kit O2 and Iron Stuff combinations do not enhance the stain removal action compared to Copper and Scale Stuff alone, so I guess I'm left with mostly copper stains, which isn't surprising, given that the previous home/pool owner left a nearly empty giant blue bucket of nasty blue-speckled trichlor pucks in the pool shed. A professional lab result says our spring water contains 4.4 ppm iron and 0.0185 ppm manganese but essentially no copper, so the "plus-enhanced" trichlor pucks are almost surely the source of the remaining stain problem.
I'm thinking about treating with citric acid or perhaps sulfamic acid to see if the stains will lift (leaning towards sulfamic acid, because the Jack's Copper and Scale treatment produced the best results).
Both citric and sufamic acid treatments appear to impose post-treatment challenges. Citric acid chews up chlorine like crazy during post-treatment re-balancing and sulfamic acids seems very likely to knock alkalinity and pH off the map! I guess either method might produce another big dust cloud in the water like the one that cost me the end of the swimming season last year so maybe I'll wait for the water temp to hit 65 F before I begin my next full-on stain assault (too cold for pleasant swimming but still barely warm enough for stain treatments). It's now a very pleasant 78F.
What to you experts here at TFP think? Citric or sulfamic?
Are the specialty formulations of Jack's sequestrants worth the extra money over just the plain ol' HEDP in MM?
Thanks a bunch for thoughts and advice!
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