Warning to readers: Do not do this until Chem Geek has commented.
This one is definitely for Chem Geek,
Chem Geek as you are aware I just tried the "Hydrogen Peroxide Method" (see other post- "Used Hydrogen Peroxide for Removing Metal Stains - Results" adding 304 ozs of the 3% solution to my pool.
As you also know I add an HEDP sequestrant to the pool, Jack's Magic Purple Stuff, which contains phosphates. Many months ago I took a diluted phosphate reading and I stopped after 20,000 ppb. The phosphates as so often mentioned on this site are not an issue so long as the Free Chlorine and CyA are kept in check. Still a little annoying to know they are there. My guess is that they were in excess of 40,00 ppb when I started this method.
Being a little concerned that Hydrogen Peroxide and phosphates together might create an issue or problem in my pool I "Googled" this and found the following article at the "Journal of Hazardous Materials", titled "Removal of phosphate from secondary effluent with Fe2+ enhanced by H2O2 at nature pH/neutral pH":
If I read the article correctly too much Hydrogen Peroxide is not of benefit and can be detrimental to the process, but the presence of iron in the process is beneficial, but what would be the ideal quantity per 10,000 gals of 3% and 27.5% Hydrogen Peroxide solution.
Today, 6 days after the "Hydrogen Peroxide Method" and after adding 6 ozs of the Purple Stuff this morning I got my trusty Phosphate testing kit out and it seems that the reading is now 2,500 ppb. This with adding just 304 ozs of Hydrogen Peroxide in my SWG 10,000 gal pool, 6 or so days ago, a possible drop of around 37,000 ppm.
Very Important Warning: When you add Hydrogen Peroxide you remove all your chlorine and should only be done at night so there is no chance of an algae bloom see other post mentioned above for further details. You must add back chlorine before sunrise to get to your maintenance level in my case 5 or 6, 2 x 184 oz jugs of Clorox Non-Scented and acid to rebalance your pH
It seems from the article that the ideal pH to do this at is 7.2, which is where I started "Used Hydrogen Peroxide for Removing Metal Stains - Results".
This seems like a very inexpensive and less bothersome way of removing phosphates, with added benefit of removing metal stains. There was very little stuff in the filter, when I backwashed after 4 days, so where did the phosphates go to? Chem Geek please help.