Were not monitoring orp, our threads are strictly driven by pics and testimony, pure highly repeatable anecdote!
Tanks are unique with many variables so reliable repeatablility of dosing levels based on anecdotal experiences in different aquariums dosing levels is very imprecise if not unlikely. For just one example a tank with high orp might tolerate less H2O2 than otherwise.
ORP measures a condition of the water and is a bit more universal. I could give a clue as to when generally harmful oxidation levels are reached, say 500mv in a particular aquarium. This is why folks use ORP controllers with ozone.
In doing online reading we can see how orp is initially lowered by the first tankwide dose, never bothered to follow it long term. Our collective dosers are usually pretty frustrated by the time they show up looking to join the challenge
H2O2 is an oxidizer . It raises orp ; it does not lower it.
Here is a reference, an article by Randy:
http://reefkeeping.com/issues/2003-12/rhf/feature/index.php
and this from it:
If the solution is dominated by atoms, molecules, or ions that want to pick up electrons, then the measured ORP will be high. In a sense, they want to pull electrons out of the ORP probe, raising the measured voltage. Examples of oxidizing species are shown in Table 1.
<table align="center" bgcolor="#CCECFF" border="2" cellpadding="2" cellspacing="1" width="99%"> <tbody><tr> <td colspan="3">
Table 1.� Oxidizing species in marine aquaria.
</td> </tr> <tr><td width="33%">
[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Oxidizing Species:[/SIZE][/FONT]</td> <td width="36%">
[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Product After Reaction:[/SIZE][/FONT]</td> <td width="31%">
[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]Relative Oxidizing Ability:[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
O[SIZE=-2]2[/SIZE][SIZE=-1] (oxygen)[/SIZE][/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
H[SIZE=-2]2[/SIZE]O (water)[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
High[/SIZE][/FONT]</td> </tr> <tr> <td width="33%" height="18">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
O[SIZE=-2]3[/SIZE][SIZE=-1] (ozone)[/SIZE][/SIZE][/FONT]</td> <td width="36%" height="18">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
OH<sup>[SIZE=-2]<sup>-</sup>[/SIZE]</sup> (hydroxide ion)[/SIZE][/FONT]</td> <td width="31%" height="18">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Extremely High[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
H[SIZE=-2]2[/SIZE][FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]O[SIZE=-2]2[/SIZE][SIZE=-1] (hydrogen peroxide)[/SIZE][/SIZE][/FONT][/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
H[SIZE=-2]2[/SIZE]O (water)[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Very High[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Fe[SIZE=-2]<sup>+++</sup> [/SIZE](ferric iron)[/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Fe[SIZE=-2]<sup>++</sup> [/SIZE](ferrous iron)[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Medium[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
I[SIZE=-2]2[/SIZE] (iodine) [/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
I[SIZE=-2]<sup>-</sup>[/SIZE] (iodide)[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Medium[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
IO[SIZE=-2]3[/SIZE]<sup>-</sup> (iodate)[/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
I[SIZE=-2]<sup>-</sup>[/SIZE] (iodide)[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
High[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
MnO[SIZE=-2]4[/SIZE]<sup>-</sup> (permanganate)[/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Mn<sup>++</sup>[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Very High[/SIZE][/FONT]</td> </tr> <tr> <td width="33%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
NO[SIZE=-2]3[/SIZE]<sup>-</sup> (nitrate)[/SIZE][/FONT]</td> <td width="36%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
NH[FONT=Arial, Helvetica, sans-serif]3[/FONT] (ammonia), N[FONT=Arial, Helvetica, sans-serif]2[/FONT](nitrogen gas), etc.[/SIZE][/FONT]</td> <td width="31%">[FONT=Georgia, Times New Roman, Times, serif][SIZE=-1]
Medium[/SIZE][/FONT]</td> </tr> </tbody></table>